Washington Gardener March 2018

MARCH 2018 VOL. 13 NO. 1

WWW.WASHINGTONGARDENER.COM

WASHINGTON WAS ASHINGTO AS HINGTO W

gardener

he magazine for gardening enthusiasts in the Mid-Atlantic region

The Secrets to Growing Plentiful Peanuts Brighten Up with Native Zizia Aurea Latest Research on Renewing Urban Landscapes New Invasive Pest on the Horizon: Allium Leafminer Digging into the Soil Microbiome

A New Look at Mahonia

Your Garden Task List 5 Easy Steps to Fabulous Lilies DC-MD-VA Gardening Events Calendar

Haven’s Natural Brew Tea conditions the soil so your plant’s root system can better absorb nutrients needed to build a strong, healthy root base. The manure tea can also be applied to compost piles to accelerate the composting process.

Order some today at: www.manuretea.com

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RESOURCESsourc

Need a Garden Club Speaker?

Washington Gardener Magazine’s staff and writers are available to speak to groups and garden clubs in the greater DC region.

Call 301.588.6894 or email KathyJentz@gmail.com for available dates, rates, and topics.

RARE AND EXCEPTIONAL PLANTS FOR THE DISCRIMINATING GARDENER AND COLLECTOR Barry Glick Sunshine Farm and Gardens 696 Glicks Road Renick, WV 24966, USA Email: barry@sunfarm.com

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Contact kathyjentz@gmail.com or call 301.588.6894 for ad rates. The ad deadline is the 10th of each month. Please submit your ad directly to: KathyJentz@gmail.com.

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WASHINGTON GARDENER MARCH 2018

www.greenspring.org

A “must visit” for everyone in the metropolitan Washington, DC, area. It’s a year-round goldmine of information and inspiration for the home gardener. It’s an outdoor classroom for children and their families to learn about plants and wildlife. It’s also a museum, a national historic site that offers glimpses into a long, rich history with colonial origins.

Located at 4603 Green Spring Rd., Alexandria, VA. Information: 703-642-5173.

INSIDEcontents

FEATURES and COLUMNS

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Many peanut cultivars can also be grown in large, wide containers such as whiskey or wine halfbarrels with drainage holes. The width is necessary so the pegs can descend into the potting medium and the peanut pods have plenty of room. Pictured here are ‘Tennessee Red’ peanuts. Photo courtesy of Baker Creek Heirloom Seeds.

Dr. Timothy Beatley’s work focuses on the subject of sustainable communities and creative strategies by which cities and towns can fundamentally reduce their ecological footprints, while becoming more livable and equitable places. Beatley believes that sustainable and resilient cities represent our best hope for addressing today’s environmental challenges.

Beatley is the author or co-author of more than 15 books on these subjects.

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Mahonia is still called holly-leaved barberry by some.

New introductions like ‘Soft Caress’ Mahonia are making gardeners rethink their use of the plant. Photo by Southern Living® Plant Collection.

BOOKreviews 6-7 Composting; Bountiful Bonsai; Visual Guide to Harvesting EDIBLEharvest 16-17 Peanuts GOINGnative 5 Golden Alexanders GREENliving 18-19 Green Matters: Restoring and Renewing Urban Landscapes HORThappenings 12 Seed Exchanges; RootingDC; Flower Show Trips; Orchid Show INSECTindex 22 Allium Leafminer NEWPLANTspotlight 11 Zinnia ‘Forecast’ NEIGHBORnetwork 14-15 Dr. Timothy Beatley PLANTprofile 14-15 Mahonia TIPStricks 10 Lily Growing Tips; Soil Microbiome; Spring Project Prep

DEPARTMENTS

ADVERTISINGindex BLOGlinks EDITORletter LOCALevents MONTHLYtasklist NEXTissue RESOURCESsources

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ON THE COVER

‘Marvel’ Mahonia Photo courtesy of Southern Living® Plant Collection.

In our April 2018 issue:

Azalea Plant Profile

A Visit to Poplar Forest and much more...

If your business would like to reach area gardeners, be sure to contact us by April 10 so you can be part of the next issue of our growing publication!

Be sure you are subscribed!

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EDITORletter

Credits Kathy Jentz Editor/Publisher & Advertising Sales Washington Gardener 826 Philadelphia Ave. Silver Spring, MD 20910 Phone: 301-588-6894 kathyjentz@gmail.com www.washingtongardener.com Call today to place your ad with us!

Allison O’Reilly Kelly Zheng Interns Ruth E. Thaler-Carter Proofreader Cover price: $4.99 Back issues: $6.00 Subscription: $20.00 Address corrections should be sent to the address above.

• Washington Gardener Blog: www.washingtongardener.blogspot.com • Washington Gardener Archives: http://issuu.com/washingtongardener • Washington Gardener Discussion Group: http://groups.yahoo.com/group/ WashingtonGardener/ • Washington Gardener Twitter Feed: www.twitter.com/WDCGardener • Washington Gardener Facebook Page: facebook.com/ WashingtonGardenerMagazine

Flower Show Madness

In a few days, spring will have officially sprung, but I can tell it is already here by the huge increase in emails and social media messages I have been getting over the past few weeks. Everyone is eager to get out and clean out their garden beds.

The earliest-blooming bulbs, shrubs, and trees are telling us the time is nigh!

For me, spring begins with my trips up to the Philadelphia Flower Show. That wonderful Disneyland-esque experience is a full immersion into the season ahead.

A B12 shot for the green soul. I always leaving there practically vibrating with plans for my own home garden and many story ideas to share with all of you. I hope you enjoy this issue and get inspired to grow something fun or new in your own garden.

Happy gardening!

Kathy Jentz Editor/Publisher, Washington Gardener, KathyJentz@gmail.com 4

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• Washington Gardener is a womanowned business. We are proud to be members of: · Garden Writers Association · DC Web Women · Green America Magazine Leaders Network · Green America Business Network To order reprints, contact Wright’s Reprints at 877.652.5295, ext. 138.

Volume 13, Number 1 ISSN 1555-8959 © 2018 Washington Gardener All rights reserved. Published quarterly.

No material may be reproduced without prior written permission. This magazine is purchased by the buyer with the understanding that the information presented is from various sources from which there can be no warranty or responsibility by the publisher as to legality, completeness, or technical accuracy.

All uncredited photos in this issue are © Kathy Jentz.

GOINGnative

Golden Alexanders (Zizia aurea)

By Barry Glick

Of the three native species in the genus Zizia, Zizia aurea is the most widely cultivated. Zizia is a member the very large Apiaceae family, the same family as carrots, celery, fennel, cilantro, etc.

Most of the plants in this family are annuals and biennials. Fortunately for us, the charming Zizia aurea is a perennial. Many consider it to be a short-lived perennial, but due to its proclivity to gently seed itself into a nice little colony in my garden, it’s difficult for me to tell.

Zizia aurea AKA “Golden Alexander” is a virtually indestructible plant and a bright spot in the garden for an extended period from late spring to early summer. In nature, it occurs in moist woodland thickets, but it grows happily for me in average soil in full shade and also in full sun.

I’ve heard tales of Zizia reaching heights of 36", but in my garden, they seem to top out at 12–18".

Zizia aurea is native to all across the

continent, excepting 10 Western states, and I can’t imagine a climate or garden situation where it wouldn’t thrive, even in clay soils.

The clusters of long-lasting, brightyellow flowers are a welcome sight not only to us bipeds, but to many of our important pollinating friends. They are an important nectar source for many species of “short-tongued” bees and other insects. The leaves are a significant food source for the caterpillars of several species of swallowtail butterflies.

Zizia aurea has no serious insect or disease problems. It is also 100% deerproof in my experience.

As far as the name goes, although I can’t tell you who the particular “Alexander” is, I can share that the genus name is in honor of German botanist Johann Baptist Ziz. Aurea is from the Latin word for “golden-yellow.”

Beware! A nasty look-a-like is Wild

Parsnip (Pastinaca sativa), which is a highly invasive Eurasian biennial often seen along roadsides. Wild Parsnip can cause a painful rash if handled.

Zizia aurea looks good in mass plantings and combined with Indian Paintbrush, Blue Eye Grass, and Geranium maculatum. o Barry Glick, a transplanted Philadelphian, has been residing in Greenbrier County, WV, since 1972. His mountaintop garden and nursery is a mecca for gardeners from virtually every country in the world. He writes and lectures extensively about native plants and Hellebores, his two main specialties, and welcomes visitors with advance notice.

He can be reached at barry@sunfarm.com, www.sunfarm.com, or 304.497.2208.

Photo taken by Superior National Forest (Zizia_aurea_2 Uploaded by AlbertHerring) [CC BY 2.0 (http://creativecommons. org/licenses/by/2.0)], via Wikimedia Commons.

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BOOKreviews

Square Foot Gardening—Growing Perfect Vegetables: A Visual Guide to Raising and Harvesting Prime Garden

By Mel Bartholomew Foundation Publisher: Cool Springs Press List Price: $17.99 Reviewer: Kelly Zheng Square Foot Gardening (SFG)— Growing Perfect Vegetables is written for everyone; whether you are a beginner, experienced home grower, or even a market shopper looking to maximize the value of your produce purchases.

The guide explains how to know when your vegetable is ripe enough to harvest and consume.

The guide is a visual one, so you can only imagine the number of the photos in it. I appreciate them, since I learn the best this way. There are three main chapters, excluding the introduction and index in the contents.

The book tells you about What is Ripe, The Ripeness Listings, Inside the Box, Outside the (SFG) Box, Market Produce, and Making the Most of Ripeness.

In the introduction, the author discusses his founding of SFG and its theories and practices in no more than five pages. Bartholomew also refers to the SFG method throughout the book, but that does not take away from the actual purpose. He did say, “SFG limits harvests to what you can realistically use and makes it easier to determine ripeness,” for those interested.

As suggested by its title, the chapter “What Is Ripe” explains the definition along with tips on how to identify ripeness. Yellow boxes highlight certain top6

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ics. This chapter is not long, either. It mentions specific fruits and vegetables as a preview for the next one.

“The Ripeness Listings” is split into three sections: Inside the SFG box, Outside the SFG box, and Market Produce. This chapter is also the bulk of the guide, which is perfect since there are 63 fruits and vegetables altogether. They are listed in alphabetical order in each section with a brief introduction, In the Market and Extending Ripeness information, and a bar showing “Optimal Planting and Harvest Times.”

I found the photos vibrant and useful, since Bartholomew shows different examples on what is ripe, under-ripe, or overripe. They were also captured in engaging ways to bring life to the guide; they are not too similar.

After cabbage, there is a spread of the “10 Healthiest Ripe Fruits and Vegetables” with kale ranking first and carrots last. This provided different insights, showed “10 Incredibly Beautiful Ripe” later on in the next section. Exotic fruits were also shown the in next.

More vegetables are mentioned in the first section, while more fruits are in the other two. Since there are only five listed under “Market Produce,” this shows how simple it is to grow the rest yourself.

The last chapter, “Making the Most of Ripeness,” provides a chart of short-term produce storage for quick reference; how long it can stay in the refrigerator, on the counter, or counter then fridge.

This is not a pocket guide, but it is a useful read or reference—who does not want beautiful produce after expending so much time, energy, and money?

I would recommend this guide as you get ready for your spring gardening.

Kelly Zheng is a junior multiplatform journalism major, with a minor in technology entrepreneurship, at the University of Maryland, College Park. This spring semester, she is an editorial intern at Washington Gardener.

Composting for a New Generation

By Michelle Balz Publisher: Cool Springs Press List Price: $22.99 Reviewer: Allison O’Reilly

Composting for a New Generation

by Michelle Balz is the perfect guide to composting. She covers everything from why composting is important to how to get started, different techniques, and what to do with finished compost. The book breaks down the issues simply and cohesively, and even features great explanatory images by Anna Stockton.

The book is split into eight sections: The Expected and Unexpected Benefits of Composting; The Science of Composting; Composting Basics; Maintaining Your Compost Bin; In-Vessel Composting Techniques; Integrated Composting; Vermicomposting; and Harvesting and Using Your Finished Compost. The book also features two appendixes—one for composting recipes and another for deciding on a composting style. This may seem like a lofty read, but it’s image-heavy and only 192 pages in total.

The first two sections provide a lot of great context about why composting matters and how good compost comes to be. They give helpful background for the remaining chapters and could even serve as inspiration for when composting gets tough and you need to remember reasons to do it.

The Composting Basics chapter uses images and graphics to describe what can and cannot be composted and the skills and tools needed to do the job. The chapters on Maintaining Your Compost Bin, In-Vessel Composting Techniques, Integrated Composting,

BOOKreviews and Vermicomposting go more in-depth on the topic, but still manages to avoid being complicated.

The entire book is very image- and graphic-heavy, making the written words much easier to understand and follow. A myriad of composting options is featured in this book—there’s bound to be something that works for any one person or household.

The final chapter on Harvesting and Using Your Finished Compost breaks down the end to various composting techniques and shares unique uses for compost.

Overall, this book is a very easy read and simplifies the complicated subject of composting in minimal pages. The images and graphics serve as a wonderful guide to the world of composting and the narrative was written in an easy-to-understand manner. The book leaves no questions unanswered and is a dynamic look at modern-day composting.

Allison O’Reilly is originally from WinstonSalem, NC, and is a sophomore majoring in journalism as well as government and politics at the University of Maryland, College Park. This spring semester, she is an editorial intern at Washington Gardener.

Bountiful Bonsai: Create Instant Indoor Container Gardens with Edible Fruits, Herbs and Flowers

By Richard W. Bender Publisher: Tuttle Publishing List Price: $6.99 Reviewer: Erica H. Smith Bonsai, the artistic shaping of miniaturized potted plants, is a centuries-old tradition in Japan and China.

We are lucky here in the Washington area to have the National Bonsai and Penjing Museum at the U.S. National Arboretum; pay a visit if you want to see some striking, long-maintained specimens and learn more about the techniques used to create them. The majority of plants trained into bonsai are trees such as pines, maples, elms, etc.; you will also see some flowering shrubs like azaleas and camellias.

But what if you want to grow bonsai that will provide you with an edible harvest? This book will teach you how to plant, shape, and maintain fruiting trees and shrubs, perennial herbs, and

more. Will you end up with a specimen that resembles traditional bonsai?

Possibly not, but you can still produce an esthetically pleasing houseplant usable for preserves, wine, food flavorings, etc.

Bender explains the ways in which your edible container plant may vary from what you see in a tree bonsai collection: It may grow more quickly and require maintenance at a larger size; it will probably need a deeper pot and more watering; it may need to be pruned with the production of fruit in mind; it may want to be moved outside in summer but come inside again in winter (as opposed to outdoor-grown bonsai that require a chilling period).

Many of Bender’s photographed examples, especially of citrus plants, look like ordinary potted trees at first glance, but on examination, you can see how the branches have been pruned carefully to create the desired dramatic shapes. He spends a chapter on explaining how bonsai can be “carved” out of plants purchased at local nurseries or ordered through the Internet. Often, these are left to grow naturally for a period of time and then shaped, but even if the result isn’t “instant,” it can be achieved within the first year.

The main section of the book provides individual descriptions of plants suitable for edible bonsai. These include everything from bay laurel and black olive, to coffee and tea, to figs,

pomegranates, hibiscus, hot peppers, and the full range of citrus plants and herbs, plus many more.

Not every plant is pictured; the growing information is brief but sufficient for making decisions (including light and water needs). You might want to seek out additional information from other sources after making your choice, including how to deal with pests and diseases.

The following chapters explain how to shop for “future bonsai,” how to maintain plants over time, and some of the possibilities for using the harvest. The last are more-general suggestions than specific recipes.

If you have good conditions for growing houseplants and are willing to spend just a little more time to shape and maintain a specimen in a beautiful pot, you can use this book to get started on an edible bonsai adventure. o Erica H. Smith is a Montgomery County Master Gardener whose volunteer activities include the Master Gardener Demonstration Garden in Derwood, MD, the Grow It Eat It program, and speaking engagements on food-growing topics. She is the author of several novels; visit her website at ericahsmith.wordpress.com.

Garden Book Club Meeting Thursday, April 5, 6:30–8pm We will discuss A Southern Garden by Elizabeth Lawrence. We will meet at Soupergirl, right next to the Takoma Metro stop. RSVP to washingtongardener@rcn.com. The Washington Gardener Garden Book Club is free and open to all.

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TOP AREA GARDENING EVENTS DC-Area Gardening Calendar ~ Events ~ March 16—April 15, 2018 • Tuesday, March. 20, 7–8pm Microgreens: What They Are, Why They Are So Fabulous, and How to Grow Them Microgreens—You’ve likely seen them, but what makes them so good for you?

Attend this popular class to learn their many benefits, and some simple ways to grow these delicious, nutritious, and inexpensive baby plants and sprouts in your own home. Free. Advance registration requested at mgnv.org.

Held at the Shirlington Library, 4200 Campbell Ave, Arlington, VA. Questions: telephone 703-228-6414 or email mgarlalex@gmail.com.

• Wednesday, March 21, 7:30 pm Successful and Sustainable Gardening in a Changing Climate Learning some strategies for adapting to climate change and adopting climate-friendly gardening strategies will both improve gardening success and act to reduce future climate change.

This event is free and open to the public. Hosted by the Takoma Horticultural Club. Details at TakomaHort.org.

• Saturday, March 24, 8:30am–3pm Lahr Symposium Native Plants: Biodiversity in Managed Landscapes Held at the U.S. National Arboretum, this year’s Lahr Symposium explores the mounting evidence that you really can have it all—a landscape that balances artistry with sustainability.

Speakers will share their insights on landscape designs that use native plants to work in harmony with nature.

The researchers’ data and landscape professionals’ assessment both confirm: a pleasing landscape that protects ecosystems just works, and it has never been more critical to the planet’s future. Fee: $97 (FONA $76) Registration required. See http://www.usna. usda.gov.

• Saturday, March 24, 9am–3pm Garden Party & Spring Fundraiser Community Forklift’s annual Garden Party is a fun-filled event offering a ton of landscaping and garden supplies, gardening demonstrations, local experts and vendors, local bands, and 8

WASHINGTON GARDENER MARCH 2018

a local food truck. See full details at http://communityforklift.org/newsevents/calendar/.

$25 Hillwood member. Held at Hillwood.

4155 Linnean Avenue NW, Washington, DC. Register at HillwoodMuseum.org.

• Sunday, March 25, 2pm Rose Rosette Disease: An Update Dr. Mark Windham will discuss current research being conducted on Rose Rosette Disease (RRD), as well as the latest research identifying diseaseresistant varieties. Held at the U.S. National Arboretum. Hosted by the Potomac Rose Society. PRS Members: Free; FONA Members: $10.00; Nonmembers: $12.00. Register by March 24 at http://usna.usda.gov/Education/ events.html.

• March 31–May 6 Spring Blooms Relish being outdoors as Longwood’s 1,083 acres herald the arrival of spring.

Enjoy our spectacular outdoor spring bulb display, culminating in a rainbow of more than 250,000 blooming tulips in the famed Flower Garden Walk and Idea Garden. Flowering trees, shrubs, and other burgeoning blooms entice guests to explore the splendor of our landscape. Longwood Gardens is near Kennett Square, PA. Adult admission is $23. Details at longwoodgardens.org.

• Monday, March 26, 8pm Hydrangeas and Magnolia Talk Find out what’s new in two beloved genera of plants from U.S. National Arboretum Head of Horticulture and Education Scott Aker. We’ll learn about the floral morphology, new developments, and old but reliable cultivars. There will even be a sneak peak of a new shrubby magnolia that may be a game-changer.

Hosted by the Silver Spring Garden Club at Brookside Gardens’ Visitors Center/ Education Building. The meeting is free and open to all.

• Wednesday, March 28, 7:30pm Perennially Yours: Herbaceous Perennials Need Love, Too Dr. Richard T. Olsen, director of the U.S. National Arboretum, who admits his first love is woody perennials, shows some love for herbaceous perennials, too. He will highlight perennials observed in his travels to foreign lands and gardens, and ones worth experimenting with in your own gardens. Hosted by the Beltsville Garden Club in the multi-purpose room of the Duckworth School, 11201 Evans Trail, Beltsville, MD. The public is welcome and admission is free.

• Saturday, March 31, 10am—12n Branching Out: Beyond the Ubiquitous Phalaenopsis This workshop will profile a dozen orchids that go beyond the ever-present grocery store Phalaenopsis. Fee: $30,

• Tuesday, April 3, 6:30–8pm Pansy Boy with Busboys and Poets Books Artist and writer Paul Harfleet will introduce and read from his first book, Pansy Boy, a picture book he wrote and illustrated. The artist has created various incarnations of the Pansy Project, from clothing and jewelry to an award-winning garden design at the largest flower show in the world, the RHS Hampton Court Palace Flower Show, where he won a Gold Medal and Best Conceptual Garden award with his designer brother Tom Harfleet. Held at Busboys and Poets in the Takoma neighborhood of Washington, DC. • Sunday, April 7, 9am–3pm Spring Native Plant Sale Flowers, shrubs, trees, vines, and ferns will be available for purchase from a trio of Virginia-based vendors: Watermark Woods Nursery in Hamilton; Hill House Farm and Nursery in Castleton; and Nature by Design in Alexandria. The sale, sponsored by Loudoun Wildlife Conservancy, is staffed by volunteers who have knowledge of native plants.

Held at Morven Park, 11623 Southern Planter Lane, Leesburg, VA. • Sunday, April 7, 1pm Gardening with the Monarch Butterfly in Mind Delve into the world of Monarch’s with Barbara Fennelly as she discusses

TOP AREA GARDENING EVENTS DC-Area Gardening Calendar ~ Events ~ March 16—April 15, 2018 their life cycle and migration patterns.

Discover the benefits of protecting the Monarch and principles for creating a butterfly-pollinator habitat in your garden. Learn how you can make a difference in the conservation of a unique and fascinating species that without our help may become lost. Free, but registration requested at Behnkes.com.

Held at Behnkes, 11300 Baltimore Ave, Beltsville, MD. • Saturday, April 7, and Sunday, April 8 Beautiful Blooms: Flowering Plants on Stamps This event includes stamp art featuring flowers and other elements of a garden, such as birds and flowering trees and features preliminary art and conceptual designs, as well as finished stamps. You can learn more about the exhibition here: https://postalmuseum. si.edu/beautifulblooms/index.html. In support of the exhibition, NPM will host a Garden Party Family Day in collaboration with Smithsonian Gardens and Smithsonian Institution Libraries. This is the first year we have held this specific event, but our Family Days are one or two days of educational fun, demonstrations, curator talks, games, children’s stories, and craft workshops all centered on a specific theme or exhibition.

• Friday, April 13 and Saturday, April 14 Spring Garden Market Vendors from across the Mid-Atlantic region will be selling a wide variety of plants and seeds, along with garden decor, accessories, books, and botanically themed art at River Farm, home of the American Horticultural Society, Alexandria, VA. A food truck will offer refreshments, or you may bring a picnic to enjoy.

• Saturday, April 14, 10—11:30am Eco-Friendly Gardening Practices Join horticulturalist Brenda Skarphol as she highlights practical spring gardening tasks in the gardens at Green Spring Gardens in Alexandria, VA. Get tips on eco-friendly plant selection, planting, and maintenance for your own garden. Learn how to keep your garden showy throughout the seasons while

keeping a healthy environment in mind.

Dress for the weather. $18/person.

Register online at www.fairfaxcounty. gov/parks/parktakes using code 290 201 5601 or call 703-642-5173.

• Saturday, April 14, 2–7pm, and Sunday, April 15, 9am–1:30pm 68th Annual Daffodil Show The Washington Daffodil Society is holding its annual daffodil show at the Alexandria Scottish Rite Temple, 1430 West Braddock Road, Alexandria, VA. The show features different forms and colors of this spring flower, including the popular trumpet and large-cupped daffodils, along with lesser-known small-cup, double, split-cup, and miniature daffodils. In addition to exhibits of daffodils, the show includes a design category and a multi-category photography contest, with photographs to feature daffodils. For more information, see the WDS website at http://thewashingtondaffodilsociety.org/.

• Saturday, April 14, 6—8pm Botanical Cocktail Complements: Herbal Tonics, Bitters, Shrubs, and Sodas The practice of pairing spirits with botanical infusions and syrups for both medicinal and epicurean purposes has a colorful history spanning the globe and human culture. Join Dwight Grimm, of Little Alchemist Farm for an evening of tasting adventure and travel back in time to sample and discuss the recipes and practices driving cocktail concocting from antiquity to the present. Program is intended for those 21 years of age and older. Small bites and beverage samples will be provided. Doors open at 5:45 p.m. Fee: $30/$35. Pre-registration required, visit www.USBG.gov/Programs. This program takes place at the U.S. Botanic Garden.

Save These Future Dates • Saturday, April 28, 12n–4pm MD Grow It Eat It Spring Open House A fun event about growing anything edible! Meet with master gardener consultants, attend classes, demonstrations, tables of information, and visit

our plant sale. Held at the Agricultural History Farm Park, 18400 Muncaster Road, Derwood, MD. See: https://www. eventbrite.com/e/university-of-maryland-grow-it-eat-it-spring-2018-eventtickets-41384245392.

• Sunday, May 6, 1–5pm Potomac Rose Society Presents: 3rd Annual Mid-Atlantic Symposium on Disease-resistant Roses The event features Paul Zimmerman, internationally recognized rose expert and author of Everyday Roses. Learn how to establish and maintain healthy garden roses without the use of synthetic chemicals, as well as which roses perform well locally in challenging conditions such as low light, poor drainage, tight spaces, etc. Participate in a guided tour of the Brookside rose garden. Held at Brookside Gardens, 1800 Glenallan Ave., Wheaton, MD. The symposium is free and open to the public.

• Sunday, May 20 from 10am-12noon Herb Festival Washington Gardener magazine will host an Herb Talk and Tasting on at the Takoma Park Farmers Market. The event will include a seed-starting activity and samples of different culinary herbs. See http://takomaparkmarket. com/ for location details.

Still More Event Listings

See even more event listings on the Washington Gardener Yahoo discussion list. Join the list at http://groups.yahoo. com/group/WashingtonGardener/.

How to Submit Local Garden Events

To submit an event for this listing, contact kathyjentz@gmail.com — put “Event” in the subject line. Our next deadline is April 10 for the April 2018 issue, for events taking place April 16–May 15.

Spring officially begins with the Spring Equinox on Tuesday, March 20! o MARCH 2018

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TIPStricks

Use Cold Days to Plan for Spring Garden Projects

Success with Lilies

Lilies are native to the entire Northern Hemisphere. They have been seen as a flower of significance for thousands of years because of the extensive symbolism that surrounds them. The lily represents femininity, love, purity, and a sense of transience, but lilies also have a wonderful history. In 1150, King Louis of France used an image of a lily on his shield as a symbol of his name (Louis or Loys) and power. The lily is also portrayed as a focal point in many historical paintings.

The lily was selected by iBulb.com to be the official Summer Bulb of 2018, making it the perfect flower for your garden this season. Follow these five steps for a successful lily planting.

• Step One: Pick a spot with a lot of sun to plant your lilies. They prefer a bright area.

• Step Two: Dig a 4- to 6-inch hole for your lilies. It’s better to plant lily bulbs too deep than too shallow—planting them deep keeps them cool and encourages the development of strong stems.

• Step Three: Loosen the soil at the bottom of the planting hole and put in the lily bulbs. Keep the bulbs six inches apart, so each plant can receive enough sunlight.

• Step Four: Cover the holes with soil.

• Step Five: Immediately give the lily bulbs water. This helps their roots start growing sooner.

Lily bulbs can also thrive in pots or plant containers, but make sure they have holes in the bottom, so excess water can drain out.

Lily bulbs should be planted as soon as they are purchased for optimal growth and beauty. If you can’t plant them after purchase, store them in a cool, dark place like your refrigerator to keep small shoots from growing out of the bulb.

When your lilies are flowering, cut off spent flowers, but leave two-thirds of the stem. This keeps your lilies strong and healthy for years.

The best time of year to plant Madonna and Trumpet lilies is in the fall to ensure the best possible flowering.

Other kinds of lilies can be planted in either the spring or fall. o 10

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Soil microbes living under your turfgrass help your grass get nutrients and contribute to the world’s largest collection of biodiversity. Credit: SV Fisk.

Soil Microbiome

Microbes are in a lot of places—our bodies, medicine, and even in the soil. Soil is home to the world’s greatest biodiversity. In an early February “Soils Matter” blog post, the Soil Science Society of America (soils.org) explained how much of an impact the soil microbiome has on the health and productivity of plants.

According to the blog post, the soil microbiome is the combination of fungi and bacteria in the soil.

“The health of the soil microbiome can affect the health of the plants living in it,” Jo Anne Crouch, USDA-ARS, wrote in the post. “Many of the worst diseases in crops or other environments are linked with changes in the soil microbiome. And many of the changes made in soil affect both the soil microbiome and the plants that live in them.”

The U.S. National Mall hosts an incredible population of microbes, even though that is a mostly urban area—1,600 species were found during renovations to the lawn in 2010.

“Just like humans live in towns and cities where people cooperate, soil microbes rarely act alone. They normally occur as populations within complex communities, the soil microbiome,” Crouch wrote.

The soil microbiome also affects food supply—agricultural and natural spaces are incredibly vulnerable to change.

“Microbiomes offer a new and almost entirely untapped opportunity to influence interactions among plants and microbes to improve plant productivity and health,” Crouch wrote. o

There is no time better than winter to plan for spring landscaping and design projects. The Outdoor Power Equipment Institute (opei.org) offers some suggestions for getting a jumpstart on spring projects.

• Map out a plan for improving your outdoor living room. Yards are an extension of the home, providing a space for families to gather, and for kids and pets to play. Think of amenities that would improve this space for your household.

Additions like an outdoor kitchen, firepit, pergola, and patio are larger, morecostly items that you should start planning and saving for far in advance.

• Determine which plants are best for your climate. Selecting the proper plants, trees, and shrubs for your climate zone is important to keep minimizing maintenance and maximizing benefits to your environment and ecosystem. Reference the USDA’s plant hardiness zone map to determine which plants will work best in your area now so your spring shopping trip to the local nursery will be a breeze.

• Take stock of your lawn and landscape tools. Does your outdoor power equipment need a tune-up or maintenance before the spring season? Have you been living in an apartment and now need to purchase equipment such as a lawn mower, edger, or leaf blower for your home with a lawn? Now is a good time to take care of these tasks, so you will be prepared as soon as spring comes around.

• Decide now if you need professional assistance. You might be able to take on your outdoor home improvement projects on your own, but if you think you might need professional assistance, it’s better to line up consultants and obtain bids sooner than later. Organizing this now will put you far ahead the spring rush! o Tips column compiled by Allison O’Reilly.

She is originally from Winston-Salem, NC, and is a sophomore majoring in journalism as well as government and politics at the University of Maryland, College Park. This spring semester, she is an editorial intern at Washington Gardener.

GARDENnews

Quick Links to Washington Gardener Blog Posts

• Hellebore Plant Profile • How to Plant a Crocus Lawn • DIY: Succulents in Sand Terrarium • Winter Jasmine Plant Profile • Milkweed for Monarchs Project See more Washington Gardener blog posts at: WashingtonGardener.blogspot.com o

March-April Garden To-Do List

New Plant Spotlight

Zinnia ‘Forecast’ The forecast is for zinnias all summer long with a new variety of seeds called ‘Forecast’ Zinnia. This long-lasting zinnia blooms almost endlessly, and the plants are tenacious enough to thrive in virtually any growing conditions.

‘Forecast’ Zinnia boasts mildew resistance that makes it a great choice for cut flowers in damp, humid growing zones like the Mid-Atlantic U.S. The annual plants bear purple, pink, orange, salmon, yellow, or cream petals that surround bright-yellow stamens for a bloom that measures 2-3 inches across. The flowers reach up to 30 inches tall and the plants can reach a spread of 24 inches.

Zinnia may be grown from seed sown early indoors and transplanted outside after frost, or sown directly in the garden after frost. A packet of 50 seeds sells for $5.99 exclusively from www. burpee.com, 1-800-888-1447. o

Zinnia photos courtesy of Burpee.

• Avoid walking on and compacting wet soil in the garden.

• Prune grapevines.

• Put up trellises and teepees for peas, climbing beans, etc.

• Plant peas, potatoes, beets, turnips, radishes, cabbage, mustard greens, onion sets, carrots, and kale.

• Set out traps for mice, moles, and voles.

• Get a soil test.

• Do soil preparation—add lime, compost, etc., as needed.

• Mulch beds with a light hand.

• Start or update your garden journals.

• Clean out any old debris from last season from your growing beds.

• Turn your compost pile.

• Repot root-bound houseplants and start fertilizing them.

• Clean leaves and debris from your water garden.

• Do not be alarmed if your pond turns green from algae bloom—this is natural until your water plants fill the surface area. Add a barley ball to combat it for now.

• Cut back ornamental grasses.

• Water during dry spells.

• Cut your Daffodils for indoor bouquets, but do not combine daffs with other flowers in one vase. They give off a toxic substance that may kill off your other blooms prematurely.

• Weed by hand to avoid disturbing newly forming roots.

• Walk your garden—look for early signs of fungal disease.

• Divide perennials and herbs.

• Fertilize new growth.

• Plant and prune roses.

• Transplant small trees and shrubs.

• Buy or check on your stored summer bulbs (such as dahlias and caladiums). Pot them and start to water if you want to give them an early start on the season.

• If you started seeds last month, thin them and start the hardening-off process.

• Start some more seeds—try flowering annuals like impatiens and petunias.

• Prune fruit trees as their buds are swelling. Check for dead and diseased wood to prune out. Cut a few branches for indoor forcing, if desired.

• Build a raised bed for vegetables. Add lots of manure and compost.

• Buy an indoor plant to liven up your office space. Try an orchid or African violet.

• Cut back and clear out the last of your perennial beds.

• Feed birds and provide nesting materials (try dryer lint), as well as houses for the start of their family season.

• Plant a tree for Arbor Day. Arbor Day falls on different dates in different states.

In our area, it is the first Wednesday in April for Maryland. Virginia has it on the second Friday in April, and DC has it on the last Friday in April. In addition, many local groups and towns have their own celebrations.

• Read a good gardening book or magazine.

• Cut some branches (Forsythia, Quince, Bittersweet, Redbud, etc.) for forcing into bloom and enjoying indoors. o MARCH 2018

WASHINGTON GARDENER

11

HORThaenings

Seed Exchanges

Washington Gardener magazine held its 13th annual Seed Exchanges at Brookside Gardens on Jan. 27 and Green Spring Gardens on Feb. 10.

Similar to previous years, gardeners brought seeds to swap with others.

Attendees received expert advice from three speakers at each event. Each participant left with a bag full of seeds and Corona gardening tools.

Kim Roman, a Square Foot Gardening Certified Instructor, and Elizabeth Olson, a Certified Professional Horticulturist with the Maryland Nursery, Landscape, and Greenhouse Association, spoke at Brookside Gardens. Roman told attendees how to plan and organize with a calendar for quicker planting this spring.

Olson gave gardeners a better sense of where to obtain cover crop seeds, when and why to use them, and which varieties grow best here in the Mid-Atlantic.

Olson was joined by Niraj Ray, founder of Cultivate the City, to speak at Green Spring Gardens. He talked about local vertical farming, a method that uses stackable growing containers on rooftops, balconies, abandoned lots, or front yards. Olson explained how planting flowers year-round provides honey bees with pollen and nectar.

Washington Gardener editor and publisher Kathy Jentz gave a bonus talk at both exchanges on the importance of seed saving.

USBG Orchid Show

The U.S. Botanic Garden presents Orchid Spectrum from now through April 8. This annual orchid exhibit, in partnership with Smithsonian Gardens, highlights the world’s largest plant family and the USBG’s most-extensive plant collection.

The amount of flowering plants provides many creative photos, since they 12

WASHINGTON GARDENER MARCH 2018

are open to wide interpretation.

This orchid showcase has a diversity of color, habitat, scent, shape, and size. There are thousands of blooms arranged in unique displays so visitors can appreciate rarely seen ones. Some of these include an orchid arch filled with over 700 orchids, a hanging curtain of colorful orchids overhead, an orb made from 90 orchid plants, and more than 1,000 orchids mounted vertically on palms and columns in the Tropics house.

Throughout the Conservatory, visitors can find examples to answer questions in a brochure to get an orchid stamp at the end. USBG is also offering orchidthemed programs and activities for adults and children, including orchid care demonstrations and workshops, art and photography workshops, and lectures on orchid diversity and conservation. For more about the exhibit and associated programs, visit USBG at www.USBG.gov/OrchidSpectrum.

RootingDC 2018

RootingDC had record attendance this year, with more than 1,400 attendees.

The annual event took place on March 3 at Woodrow Wilson High School in Washington, DC. An information fair was held throughout the day, while various hour-long workshops took place in the classrooms. Around 60 nonprofits, green businesses, and government and educational institutions had tables during the information fair. Workshops ranged from beginner to advanced and touched on a myriad of topics.

Workshop topics included Seed Saving, Eating Well on a Budget, Advancing Racial Equality through Urban Agriculture, Worm-Powered Composting at Home, and even Cannabis Homegrowing—there really was a little bit of everything.

Mid-Atlantic Fruit and Vegetable Conference

Around 2,200 people attended the 2018 Mid-Atlantic Fruit and Vegetable Conference, which took place from Jan. 30 to Feb. 1 at the Hershey Lodge and Convention Center in Hershey, PA. It cost $90 to attend for members of an organization sponsoring the event, while others paid $125 for a one-day

pass or $165 for a three-day pass.

The keynote speaker was Charlie Arnot, CEO of the Center for Food Integrity. His speech was called “Values, Trust, and Science: Building Trust in Our Post-Truth Tribal World.” There were a variety of other speakers and workshops, as well as a trade show.

Philadelphia Flower Show

Washington Gardener magazine took two sold-out trips to the Philadelphia Flower Show, which had the theme “Wonders of Water” this year. The trips took place on March 7 and 8 at the Pennsylvania Convention Center. The show aimed to “capture all the sensory elements of the rainforest,” according to Sam Lemheney, Pennsylvania Horticultural Society chief of Shows & Events.

There were also features to highlight how eco-friendly infrastructure can work to preserve water. The William Penn Foundation gave a grant to the PHS to build an exhibit to display how plant systems cleanse and sustain the Delaware River Watershed and put together a “Water Summit” at the Flower Show.

Attendees were able to engage in the Lectures and Demonstrations series, Gardener’s Studio, and “Make & Take” workshops. o This issue’s “HortHappenings” were compiled by Allison O’Reilly and Kelly Zheng.

Both are editorial interns at Washington Gardener.

See many more photos from events listed here, as well as many more photo albums of recent local garden events, at the Washington Gardener Facebook Page: facebook. com/WashingtonGardenerMagazine. Recent albums include pictorials from the events listed on this page. Click on the PHOTOS tab, then select from the ALBUMS.

MARCH 2018

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13

History

Meet Mahonia

There is a new plant for Washington, DC-area gardeners to consider: Mahonia sps., otherwise known as Berberis sps. The time is right to take a fresh look at this genus.

Attributes

Spineless Mahonia doesn’t mean without a backbone. Narrow-leaved Mahonia doesn’t mean the spines are gone. Orange-leaved Mahonia makes the message clear for the designer, the gardener, and the appreciator.

Traditionally, Mahonia has meant prickly, broadleaf evergreen shrubs, with a quirky, overall rough, textured look. Dark-green, horizontally held leaves attach in a whorl down the stalk.

Each leaf consists of pairs of spiny, holly-like leaflets attached along the central, often red, extended stalk (it can be over a foot long), ending in a terminal leaflet.

New growth often starts with light shades of greens, and cold weather brings out a range of colorful bronze, burgundy, orange, and red leaves.

Mahonia’s rhizomes send up shoots that spread slowly but inexorably, while birds spread the seeds indiscriminately.

It is highly recognizable once identified. You may, in fact, encounter it on a walk in a local park (sightings have been reported at both Wolf Trap Park in Fairfax, VA, and Rock Creek Park in DC).

14

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Leatherleaf Mahonia at the Smithsonian's Ripley Garden, Washington, DC.

By Judith Mensh

In 2012, the Exotic Plant Management Team of the National Capital Region National Park Service wrote an “Invasive Plant Alert for Leatherleaf Mahonia (Mahonia bealei),” identifying it as invasive throughout the southeast.

While M. bealii invades the southeastern U.S., M. aquifolium—long a popular garden shrub in Europe—has created equal concern, with widely established populations in the forests of eastern Germany. British hedgerows reportedly include naturalized Mahonia aquifolium among their plant community. These two species of Mahonia are poster seedlings for scientists who work on understanding the how and why of plant invasions.

In 2018, there are new choices. New cultivars include disease resistance, non-invasiveness, color variations and intensity, narrow prickly leaves, narrow soft leaves, tall growth yet ground-hugging, shade-adapted and drought-tolerant once established Look for fragrant yellow flowers in winter and colorful blue/purple edible berries in spring. A wildlife-friendly plant, Mahonia offers color, fragrance, nectar, pollen, berries, and shelter. It’s also gardener-friendly: Its tough, (usually) spiky leaves deter deer browsing. With both color and scent, it attracts insect pollinators, while its spring berries attract birds and small animals.

Mahonia (Berberis) exemplifies the phenomenon of disjunct biogeography, observed in many instances of flora and fauna: In this case, the East Asia-Northwest America/Mexico/Central America connection, where the same genus, with individualized species, is found in unconnected locations on the planet.

The mid-20th–century discovery of intergeneric crosses between Mahonia and Berberis, named x Mahoberberis, caused a reconsideration of the validity of the two taxa being separately named, and the challenge to reabsorb Mahonia into Berberis continues today.

Two of these naturally occurring hybrids (xMahoberberis aquisargentii and xMahoberberis meithkeana) can be found through Internet sites, but not for any particular reason (and there are no recommendations from Michael Dirr).

Mahonia’s designation as a separate genus was the result of friendship and admiration, rather than science: to pay homage to Bernard M’Mahon (1775– 1816), the man who mentored Thomas Jefferson in the garden, opened the first American seed store, and was one of only two entrusted with curating the botanic collection of the Lewis and Clark expedition; Berberis was named

by Linnaeus (1753), and used by Lewis in his notes. All Mahonia are members of the family Berberidaceae.

As deserving as M’Mahon is, historically, a new biography and a garden named after him might be more appropriate, since today we have a genus with two scientific names. The two versions are commonly given as synonyms in current references to Barberry and Mahonia, one appearing in parentheses alongside the other; for example, Berberis aquifolium (Mahonia aquifolium).

The Asian Mahonia and the American native Mahonia both arrived in commerce about the same time—in the early 19th century—and gained popularity here and in Europe.

Mahonia aquifolium is well-known to the indigenous peoples of northwestern USA, who used it to make everything from yellow dyes for baskets and paints to a restorative tea from shaved roots.

They also enjoy its edible berries. Its deep-yellow dye combines well with other dyes for greens and oranges, and

PLANTprofile is still in use as a traditional natural dye.

The Lewis and Clark expedition brought M. aquifolium and M. nervosa east. Concurrently, plant explorers looking for new plants in east Asia brought us the Leatherleaf Mahonia and others of a similar prickly nature.

The history of Mahonia aka Berberis continues to unfold. Recent hybrids have focused on mining the inherent color possibilities, resulting in one called M. ‘Orange flame’, another called M. ‘Dark Star’ with burgundy leaves, and the soft-touch wave of spineless species. Mahonia x media cultivars include the popular ‘Charity’ series and ‘Winter Sun’, a hybrid Mahonia with height, drama, and no loss of fragrance as often is the case. All are available for purchase this spring in local garden centers, including Lowes, which is benefiting from a partnership with Monrovia to have more than the usual amount in stock.

As recently as 2009, a new species of Mahonia found in China was described and named. The 2013 winner of the RHS Chelsea Flower Show Plant of the Year was M. eurybracteata subsp. Ganpinensis ‘Soft Caress’ epitomizes the ongoing adventure that Mahonia offers today.

Even more recently, in 2017, a newly patented Mahonia arrived in retail, called Mahonia ‘Beijing Beauty’ (a trademarked name) and described as a new and distinct Mahonia hybrid. Developed through the Plant Development Corp. for the Southern Living Plant Collection, this new Mahonia has narrow leaves (spiny), tops out at 5' tall, and is quite handsome in situ. These also are available for purchase locally.

So far, these alternate choices have not shown up in unplanned places.

Medicinal Uses

There are medicinal and decorative uses for this genus. It has been used in Chinese traditional medicine and by the Northwest Indigenous peoples for millennia.

Cut into the vertical stem to see the bright-yellow inner bark and wood, which, along with its yellow roots and rhizomes, contain Berberine. Berberine, a bioactive compound (specifically an

alkaloid) in all Mahonia with almost mythical qualities: antibiotic, antifungal, anti-inflammatory, and known to provide relief from the stomach to the heart and outward to the skin. An ointment of Mahonia root extract is used to treat psoriasis.

Growing Conditions

Mahonia/Berberis enjoys a woodland setting, but not a swampy one; it likes moist soil, but standing water is ruinous. One great characteristic is its shade tolerance, and its comfort with a northern exposure (as long as that area is sheltered from harsh winds). It is one of the few shrubs to work in a recessed area, as is often found in townhouse front gardens.

Water faithfully in the first year. Planting is best done in the fall, giving it plenty of time and water to establish itself over the winter and spring, before the ruthless heat arrives. Once established, it is drought-tolerant.

Prune after flowering, if necessary, and always remove dead wood or damaged branches.

Mahonia species sprout from old wood, which makes cutting them to the ground a dependable and easy rejuvenation technique. This type of renewal can be done every third year, every year (for the neat and tidy landscaper), or never: gardener’s choice. Advice: Remove suckers promptly or prepare to welcome a grove, over time.

Best Cultivars

A quick look around town turns up an inventory with a nice range of choices.

‘Compacta Oregon Grape Holly’, a selection of M. aquifolium, with all of its good points, but smaller, at 2–3' tall with a 5' spread, considered a dwarf form, has established a reputation as a stalwart plant and is generally available in the spring and fall in our area.

Spineless narrow-leaved Mahonia has arrived, and like the Cinderella sister among the mean step-siblings, it’s a beautiful attention-grabber. Discovered in Japan by an intrepid American plant explorer in 1990, it is now offered commercially under the name M. eurybracteata ‘Marvel’. Its compound pinnate leaflets (slim and nearly spineless) look more like gentle fronds than the oldfashioned menacing, spikey leaflets.

Leatherleaf mahonia (Mahonia bealei) may fade into the past tense in the very near future: Along with flats of Hedera helix and Pachysandra, it may be retired from the marketplace in recognition of its invasive nature, an unintended consequence of our use of this taxa in our gardens—not to serve an ecological niche, but to provide pretty color all year-round and be undemanding. Yet, its best qualities continue to endear it to us: fragrant flowers followed by colorful berries, new foliage and winter foliage coming in shades of burgundy and orange, attracting hummingbirds with nectar and insects with its sweet smell and pollen.

Companion Plants

Comfortable in a woodland setting, in an Asian-style garden, and as a foundation plant or hedging and barriers, today there are Mahonia for a number of situations. Surrounded by Hellebore, Violets, Woodland Phlox, Pachysandra procumbens, and Pakera aurea, along with Red Twig dogwoods, Redbuds, Callicarpa, Viburnum, Rhododendron, Kalmia, and Illicium floridanum, it creates seasonal color rolling throughout the year. It’s only a question of having enough shade.

Further Sources

The Missouri Botanical Garden website describes seven species of Mahonia in its always-helpful and up-to-date Plant Finder feature.

It’s Michael Dirr’s wisdom that we consider Mahonia (and that’s the name he’s sticking to, for the time being) for its fragrant, cheerful yellow flowers in winter and eye-catching berries, leaving the work of the broadleaf evergreen to the cherry laurels of the world.

Thanks to today’s good qualities, this is a genus to keep your eyes on for adding to the diversity of your garden, and one that is moving into the future with innovation and vigor. As the old Leatherleaf Mahonia fades to dark, let the new Berberis come forward. o Judith Mensh is a local horticultural consultant. She is available to walk your yard with you and identify plants and possibilities.

She can be reached via email at JudithMenshNurtureNature@gmail.com.

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15

EDIBLEharvt

Plentiful Peanuts

by Elizabeth Olson ‘Carolina African Runner’ peanuts. Photo courtesy of Southern Exposure Seed Exchange.

Peanut plants are intriguing to grow and produce the delicious, nutritious, and familiar peanuts. Although the peanut is not a true nut, it is usually regarded as a nut for culinary purposes. It is a source of protein, dietary fiber, several B vitamins, vitamin E, and minerals including iron, magnesium, phosphorous, and zinc.

Peanuts are wonderful by themselves. They are easy to shell and can be eaten raw, or oven-roasted or fried.

Peanuts can also be boiled in their pods. Culinary products made from peanuts include cookies, mixed nuts, protein bars, peanut butter, spicy peanut sauce, and candy (see the recipe for peanut brittle on page 17.)

All peanuts have a pale, creamy-white to a very pale yellow-tan nutmeat. The skin surrounding the seeds can be a solid bright-red, brown, black, violet black, or white, and can even be multicolored or striped, depending on the cultivar.

This crop is an annual legume. Its scientific name is Arachis hypogaea.

Peanuts belong to the same plant family as beans and peas, and benefit from crop rotation. Like beans and peas, peanut plants can host nitrogen-fixing bacteria in nodules on their roots. This greatly reduces or eliminates the need for added fertilizer.

Unlike beans and peas, peanuts are formed underground. Peanut flowers 16

WASHINGTON GARDENER MARCH 2018

are self-fertilizing, after which each flower forms a peg that grows down and into the soil where the peanut pod develops and matures. Healthy plants are very productive: Each plant can produce 50 or more—sometimes a lot more—peanut pods.

How to Grow Peanuts

Peanut plants require full sun all day long throughout a long growing season.

Depending on the cultivar, the plants need 110 to 130 days or more to produce mature peanuts.

The plants grow best in slightly acidic, loose, fertile soil with good drainage.

Heavier soils should be well-worked and amended with lots of compost.

Growing peanuts in raised beds is helpful.

In the greater Washington, DC, growing region, the soil becomes sufficiently warm to plant peanuts no earlier than the last half of May. In some local micro-climates, this might not occur until the end of May. Although cultivars that require 110 days to mature can be sown directly in the garden or started indoors, the latter is the safest bet and works for all cultivars. Starting seeds indoors should be timed about four weeks early—so the seedlings are ready to be installed in the garden near the end of May. Peanut plants need good air circulation and adequate room to grow.

Both seeds and transplants should be spaced about 12 inches apart in rows 30 to 36 inches apart.

When starter plants are installed in the garden, any rims from biodegradable pots have to be trimmed down to the soil line. Seeds planted directly in the garden should first be carefully removed from their shells/pods, then planted about 1 inch deep, tamped down, and watered. They may sprout in as little as one week to as long as three weeks.

All seedlings or starter plants need to be protected with a floating row cover until they are well-established in late spring. A floating row cover can also be used to protect mature plants from early light frosts in autumn. Gardeners can guard against rabbits throughout the season by surrounding the peanut patch with a chicken wire or similar small-gauge fence.

Peanut plants need a minimum of an inch of water every week. This is especially important once the plants begin to produce pegs and while the seed pods are developing and maturing.

Using a soaker hose is the best way to supplement rainfall.

A layer of compost or fine pine mulch placed on top of the hose and any open ground in the peanut patch will help keep the area weed-free and prevent the soil from crusting when the plants are young.

Many gardeners hill the peanut plants—add soil on top of the ground around the plants—after the plants are about 12 inches tall. This is similar to the hilling done for potato plants.

It is essential that any mulch layer not be too thick for the pegs to easily enter the ground. The mulch can be carefully raked away from the plants when pegs start to form. Gentle, shallow hand cultivation can be used to keep the top of the soil loose and to eliminate any weeds without disturbing the developing and maturing peanut pods.

Availability and Sources

Starter plants and seeds are sometimes available in early spring at selected garden centers and farm markets and in seasonal displays at some big-box stores. Gardeners should check to see if a cultivar name and

EDIBLEharvt days to maturity are listed. It is best to ‘Carolina Black’ and have a darker avoid seeds and plants of jumbo- or violet-black skin. SESE. large-sized peanut cultivars, as well • ‘Talbert Small Red’. 110 days. Three as starter plants that are available too to four small-sized seeds with solid early in the season. deep red skin per pod. SESE. Seed companies that offer seeds for • ‘Tennessee Red’ or ‘Tennessee Red a variety of peanut cultivars suggested Valencia’. 110 to 115 days. Three to for the greater Washington, DC, growing four medium-size seeds per pod. The region include Baker Creek Heirloom peanuts have a uniform, deep-red skin Seeds (at RareSeeds.com) and a rich, sweet flavor. and Southern Exposure These are the easiest peaSeed Exchange (at nuts to grow in heavy soil.

SouthernExposure.com).

BC, SESE. They are the sources for • ‘Texas Red and White’. the cultivars in the follow110 days. Two to four ing list, and are noted as medium-size seeds per BC and SESE, respectively. pod. The peanuts have The list is composed of white skin that is heavily medium- to small-sized splashed with red. The peanuts, all of which can plants have a compact be used for the same culigrowth habit and can grow nary purposes as jumbowell in heavy soil. SESE. or large-seeded cultivars.

• ‘White Spanish Pearl’.

The number of days to 120 days. One to two ‘Fastigiata Pin Striped’ expected maturity is listed peanuts. Photo courtesy of small-sized seeds with directly after the name of Baker Creek Heirloom Seeds. very pale, creamy white each cultivar. skin per pod. BC. To ensure enough time in the growHarvesting and Storing ing season and the availability of a Harvest time for peanuts is when the specific cultivar, peanut seeds should plant leaves start to turn yellow as the be ordered early. Both Baker Creek season comes to an end. Mature peaand Southern Exposure choose to ship nut pods that are left in the ground too peanut seeds in their natural shells long may start to sprout in their shells. to ensure freshness and protect them Each plant should be uprooted by digduring shipping. Peanut seeds can be ging around the outside edges of the stored in their shells until just before plant and lifting it, shaking off excess planting. soil, and turning it upside down so the Recommended Cultivars peanuts can air-dry for two or three • ‘Carolina African Runner’. 130 days. days. The pods can then be pulled off One to two small, dense, tasty seeds the plant and spread in a thin layer with brown skins per pod. Plants can (preferably indoors) and allowed to dry spread 3 feet or more. This cultivar is for a few weeks before being stored in boarded on the Slow Food USA® Ark of airtight containers. The harvested peaTaste. SESE. nut pods always have to be protected • ‘Carolina Black’. 110 days. Two to from rain and vermin. three medium-small sweet seeds with Peanuts that are well-grown, -harblack skin per pod. SESE. vested, -dried, and -stored can keep • ‘Fastigiata Pin Striped’. 120 to 125 fresh in their pods and have excellent days. Three to four medium-size seeds culinary quality for many months. Any with purple-striped pink skin per pod. seeds that are not consumed during Sweet, nutty flavor. BC. the off-season can be saved for next • ‘Negrito Manduvi’. About 115 to 125 year’s kitchen garden. o days. One to two tightly packed small, Elizabeth Olson is a Maryland Certified Problack-skinned seeds per very small fessional Horticulturist. She is also an avid pod. BC. home gardener who is fascinated by the • ‘Schronce’s Deep Black’. 110 days. plants that she grows. She can be contacted Three to four medium-size seeds per through Washington Gardener magazine. pod. The peanuts are larger than

Golden Buttery Peanut Brittle Recipe and photo courtesy of Land O Lakes, Inc.

Peanut brittle makes a great gift.

Package this peanut brittle in a decorative glass jar, tin, or gift box and add a holiday decoration or bow on top.

Preparation time: 5 minutes Total time: 1 hour, 10 minutes Yield: 2¼ pounds.

Ingredients: 2 cups sugar 1 cup light corn syrup ½ cup water 1 cup butter, cut into chunks 2 cups raw peanuts 1 teaspoon baking soda Directions: Butter two (15 x 10 x 1-inch) baking sheets; set aside.

Combine sugar, corn syrup, and water in 3-quart heavy saucepan. Cook over medium heat, stirring occasionally, 8– 12 minutes or until sugar is dissolved and mixture comes to a full boil.

Add butter; continue cooking, stirring occasionally, 15–25 minutes or until candy thermometer reaches 280°F, or small amount of mixture dropped into ice water forms a hard but pliable strand.

Stir in peanuts; continue cooking, stirring constantly, 10–12 minutes or until candy thermometer reaches 305°F or small amount of mixture dropped into ice water forms a hard, brittle strand. Remove from heat; stir in baking soda.

Pour mixture immediately onto prepared sheets; spread evenly to about ¼-inch thickness. Cool completely.

Break into pieces. Store in container with tight-fitting lid. o MARCH 2018

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GREENliving

Restoring and Renewing Our Urban Landscapes

future. Her presentation was on “Lessons in Landscape Design, Integrating Natural Systems into the Built Environment.” She showed how historically we buried waterways, flattened topography, and removed vegetation, which caused massive issues when large storms hit these regions.

A big takeaway from the conference was that whether we do things to improve our garden, work as a neighborhood group, or as a business, we can improve our environment for everyone’s benefit. The speakers indicate that the most effective progress on protecting the environment will likely occur at the local level.

Anne Hilliard is the recording secretary of the Silver Spring Garden Club.

Creating Healthy Soils Green Matters 2018

By Anne Hilliard On February 23, landscape professionals, horticulturalists, master gardeners and other interested parties gathered at the civic center in downtown Silver Spring, MD, the 2018 Green Matters Symposium to learn about regenerative landscape design and gardening practices that help restore our ecosystems on a large and small scale.

The keynote speaker for the event, Dr. Timothy Beatley, presented “Biophilic Urbanism: A New Approach for Creating Sustainable Environments.”

What is biophilia you ask? The biophilia hypothesis suggests that humans possess an innate tendency to be drawn to nature, we want to engage and participate in our natural surroundings. (See more about Dr. Beatley and Biophilia on pages 20-21 of this issue.)

Following the big picture of making cities nature-friendly, we move on to the nitty gritty of soil. The second speaker Jeff Lowenfels came all the way from Anchorage, Alaska, and presented “Creating Healthy Soils Through Regenerative Gardening Practices.” Jeff discussed the Soil Food Web along with discussion on bacteria and fungi.

He described how we, as individual gardeners, can improve on garden soil and therefore the environment.

From soil discussion we moved to 18

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“Restoring Ecosystem Functionality and Biodiversity” by Heather Holm. She described the process of how her neighborhood worked together to clean up an empty lot, removing invasive plants and replacing them with natives. It was a tremendous task from start to finish, but working together, they met their goal and improved the biodiversity in their neighborhood to benefit pollinators, wildlife and themselves.

Holm noted that the use of pesticides and large amounts of turf grass, 40 million acres in the US, deteriorates the urban ecosystem. “By maintaining one’s landscape without pesticides, reducing inputs and disturbance, and creating new, or enhancing existing plantings with native flowering plants, everyone can play a small but important role in supporting bee and pollinator populations,” she said. “I want people to come away thinking differently about how they manage their landscape. I want to make their lives easier. We spend all this time in our gardens doing all these things we don’t need to be doing, and it is often counterproductive.” Her website suggestions: www.nwf.org/nativeplantfinder and www.audubon.org/nativeplants.

In the final portion of the program, Kate Hayes of SCAPE explained how a business can improve the landscape and design for change coming in the

By Kelly Zheng With humor, Jeff Lowenfels (www.jefflowenfels.com), award-winning author and columnist, provided abundant information accompanied with relatable memes and photos. He spoke to the more than 400 guests on how to create healthy soil through regenerative gardening practices. Some of these practices involve working with organic matters that already exist in the soil such as microbes, nutrients, and fungi.

Lowenfels referred to Teaming with Microbes, his first book, as he told the crowd that healthy soil is not just about earthworms and insects, but working with microbes and the soil food web.

Microbiome is the combination of bacteria and fungi within the soil.

He said the web is a community of organisms that are interconnected, because they live all or part of their lives in the soil. He added that people can strengthen the web by creating a nurturing environment for plants.

This relationship will also help improve drought tolerance.

He believes that gardeners have been brainwashed about using fertilizers, since they seem to work without question. However, multiple questionable formulas are harmful chemicals. Chemical fertilizers ruin the microbial life that sustains healthy plants and become increasingly dependent on toxic substances, according to Lowenfels.

Aside from fertilizers, he explained

GREENliving why gardeners should use compost, mulch, and compost tea instead to cultivate the life of soil. Lowenfels said everyone can create rich, nurturing, and living soil this way.

He then referred to Teaming with Nutrients, his second book, as he explained the basics of plant nutrition from an organic gardener’s perspective.

Lowenfels said most gardeners realize that plants need to be fed, but do not know about the nature of the nutrients involved.

Lowenfels talked about the role of both macronutrients (food required in large amounts) and micronutrients (normal amounts). He also showed gardeners how to provide these essentials through organic, easy-to-follow techniques, most of which focused on soil.

He said the importance of understanding the role of nutrients will result in healthy, productive organic gardens.

He added it will help gardeners become better informed, more successful, and more environmentally responsible.

Not only is understanding the food web and nutrients important to creating healthier soil, but also knowing about fungi. He referred to Teaming with Fungi, his third book, which talked about the symbiotic relationship between soil-dwelling mycorrhizal fungi and plants. Almost every plant in a garden forms a relationship with fungi, and many plants would not exist without them, according to Lowenfels. Using this essential fungi will improve the immune systems of plants.

He said gardeners should take advantage of fungal benefits after understanding the relationship. Fungi can help plants increase nutrients, resist droughts, and promote early fruiting.

Lowenfels said gardeners should know how fungi interacts with plants as they grow.

As he concluded his hour-long presentation, he emphasized that the relationships within the soil were what a successfully grown plant needs as its basic foundation.

Kelly Zheng is a junior multiplatform journalism major, with a minor in technology entrepreneurship, at the University of Maryland, College Park. This spring semester, she is an editorial intern at Washington Gardener.

Integrating Natural Systems into Landscapes

By Allison O’Reilly Kate Hayes is a registered Landscape Architect and an associate at SCAPE, a design-driven studio based in New York. She discussed her work at SCAPE and founder Kate Orff’s book, Toward an Urban Ecology.

The description for Hayes’ talk described SCAPE (www.scapestudio. com) as “a leader in creating ecological designs that integrate natural systems within urban landscapes,” which she outlined well with examples of prominent works by the company. Hayes went through chapters in Orff’s book and explained them with examples.

The first chapter she went over was “Engage,” which she contextualized with SCAPE’s Safari 7 project. “Safari 7 is a self-guided podcast tour of urban wildlife along New York City’s 7 subway line,” the project’s online description said. “The project engages the broadest range of New Yorkers, from commuters and school children to urban explorers and designers, in active research and exploration of their own environment.”

Hayes described herself and her colleagues as “educators through the creation of space.” The Safari 7 project uses their tools of engagement—connect the dots, enable landscape literacy, and create intergenerational spaces. Hayes said the project is one of her favorite SCAPE projects.

The next chapter she covered was “Cohabit,” which encapsulates advocacy in the landscape architecture field and seeks to show “this mass extinction driven by humans as an opportunity” for collaboration across various fields like landscape, architecture, biology, and sociology, according to Hayes. She listed these criteria for the Cohabit concept: Design for Adaptive Management; Design Participatory Habitat; Design to Share Space with Insects, Animals, Etc.; and Design Living Infrastructure. She used SCAPE’s Living Breakwaters project to showcase this concept.

SCAPE’s website describes the Living Breakwaters project as: “Planned for the neighborhood of Tottenville, Staten Island, the project links in-water infra-

structure with on-shore education and outreach, to help increase awareness of risk, enhance ecologies, and bring local school curriculum to the waterfront. SCAPE was commissioned by the [Governor’s Office of Storm Recovery] to lead the schematic design process with a strong coalition of ecological and engineering partners ... The team has worked closely with members of the community to create a design that benefits the community while positively affecting regional ecosystems and resiliency efforts.”

Hayes then went into the “Revive” section of Toward an Urban Ecology where she shared details of SCAPE’s American Copper Building Plaza, which is located near the East River in New York City. The project is described by SCAPE’s website as one that “serves as both an active civic space and a functional water filtration system. The water plaza, located over a parking structure, is activated by a layered water-collection system that responds to multiple types of inundation.”

The last chapter Hayes shared at Green Matters was “Scale.” In this section of her talk, she provided details of SCAPE’s Ohio Creek Watershed Resilience Project in Norfolk, VA. Hayes is the project manager of the Ohio Creek Watershed Resilience Project.

“Scale” addresses the difficulty of drawing boundaries around complex open systems. For example, “it focuses on scaling up the nitrogen cycle and water quality and down to streetscapes and more detailed and human-scaled and more tangible items,” said Hayes.

SCAPE’s website says the Ohio Creek Watershed Resilience Project “consists of an interdisciplinary team of civil engineers, stormwater engineers, architects, environmental consultants, and ecologists. SCAPE is working closely with the team to realize a watershedscale design that will make neighborhoods in Norfolk, VA, more resilient to storm surge, sea level rise, and stormwater flooding.” o Allison O’Reilly is originally from WinstonSalem, NC, and is a sophomore majoring in journalism as well as government and politics at the University of Maryland, College Park. This spring semester, she is an editorial intern at Washington Gardener.

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NEIGHBORnwork

Professor Timothy Beatley

By Kelly Zheng We recently caught up with Dr. Timothy Beatley at the Green Matters Conference, where he gave the keynote address on “Biophilic Urbanism.” He is Teresa Heinz Professor of Sustainable Communities in the Department of Urban and Environmental Planning, School of Architecture, at the University of Virginia (UVA).

and fieldwork in these cities has been an important source of insight and inspiration. I aim to capture their stories and the innovative tools and strategies they employ, and to share these in my books and other writings. The books I write largely tell the stories of what the best, most-innovative cities are doing and what can be learned from them.

Tell us about yourself and your background—where you grew up, what subjects you teach, when you started your research, what influenced you to pursue green urbanism, etc.

I grew up in Alexandria, VA; attended TC Williams High School there, and later UVA, where I teach now. I have always had a deep love of nature, but also of cities, and these are two subjects I’ve managed to blend together and integrate in my teaching and research.

At UVA, where I have now taught for the past 30 years, I teach classes that focus in one way or another on design and planning of green cities—cities that are sustainable, resilient, and biophilic.

Two of my favorite classes, “Introduction to Urban and Environmental Planning” and “Cities and Nature,” both contain over 300 students.

What is a typical day at work like for you?

I am privileged to work at a wonderful university and to teach terrific students.

Almost every day involves teaching.

Sometimes this takes the form of lectures to larger classes; others, it’s leading discussions in smaller seminars.

We often tackle difficult issues in these classes—important ideas, methods, and urban planning practices that can result in significant improvements in the health and quality of life for urban residents.

My daily interactions with faculty and staff, and the students, make my job extremely stimulating. There are a lot of things that happen during a typical day in academia, including service and committee work, but it is the teaching and research that is so enjoyable for me.

Several years ago, I helped to start and now manage a global Network of Biophilic Cities. This network is gaining traction as more cities begin to understand the power of nature, and the need to design and plan with nature at

How did you come to your role as the author of renowned books on green urbanism?

Much of my research and writing is informed by what cities around the country and the world are doing. Travel 20

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the center. We believe that access to nature is not something optional, but absolutely essential to leading a happy, healthy, meaningful life. Much of my time lately is spent working on that network, participating in calls and Skyping with cities, helping to connect cities, developing new partnerships, and working on a new online journal called Biophilic Cities, among other tasks.

What is the best part of your job as a professor? As an author?

The best part of my job is, again, the interaction with students, and the privilege of exposing them to new perspectives, new ideas, new pathways for their own professional and personal futures.

The possibility of shaping, in even a small way, a future planner or mayor, or citizen, is a big key motivator behind my teaching. I aspire to helping shift and expand the ways that students see cities and the larger world. Equally true is the privilege to work in a setting that values creativity, the power of ideas, and applied scholarship.

Writing books is another way to have an impact in the world. My books explore the many creative ways cities around the world are becoming more sustainable, resilient, and natural.

Increasingly, I believe we need to supplement the books and the writing with other media, notably films and filmmaking. This is another especially fulfilling aspect of my work. I have been collaborating for several years with a Colorado filmmaker, Chuck Davis.

Among [my] films is, “The Nature of Cities,” documenting the ways that cities in Europe and North American were fostering new connections to the natural world. It was a successful film and shown on a number of PBS stations around the country (and now watchable for free on the web: https://topdocumentaryfilms.com/nature-cities/).

We’ve just released a new film called “Ocean Cities,” about ideas for connecting cities and the sea. It is based on one of my books, Blue Urbanism (https://islandpress.org/book/blueurbanism).

What are some mistakes and triumphs you’ve faced in your careers?

Each book or film is a triumph, cer-

NEIGHBORnwork tainly. And graduating thousands of students over a 30-year career (so far), is very gratifying and a big triumph overall. Many of these students are doing really remarkable things in their lives and careers, making a remarkable difference in the world. While we can take only partial credit, it is humbling and exciting nonetheless, and overall a feeling of triumph.

In terms of mistakes, there are too many to mention! They include failing to equip our students with the skills and knowledge they need for the challenges they face (an ongoing discussion and struggle). With the larger lecture classes I have taught in recent years, I regret not being able to know them all more fully as individuals.

Can you tell us more about the concept of a “biophilic city”? What are its essential elements? Which cities have already integrated these elements?

The concept of Biophilic Cities begins, of course, with the important concept of biophilia—our innate connection with nature and living things. We know that humans as a species respond powerfully to nature: it positively affects our mood, enhances cognition, moderates stress. There is even evidence now that we are more generous and more cooperative in the presence of nature.

Nature, again, is not something that is optional, but absolutely essential.

We need nature around us where we live and work. It is not something just to experience once or twice a year on holidays, perhaps by visiting a national park. It has to be the everyday nature that we will experience daily if not hourly—trees, greenery, gardens, birds and wildlife, etc. Biophilic Cities emphasize getting people outside, and they invest in urban trails, parks, and ecological connectivity. These are also cities that look to design-in nature, for instance through ecological rooftops and living walls, among many other biophilic design elements.

So, Biophilic Cities are nature-rich cities that put the protection, restoration, and celebration of nature at the center of their design, planning, and management. They are cities that invest in abundant opportunities for residents to experience and enjoy the nature around

them. Each city will have different forms of nature; different native species and ecosystems, of course; and different ways to connect and celebrate this nature.

There is no single or perfect model of what a Biophilic City is, and many cities in our Biophilic Cities Network are experimenting with many new ways to engage with the nature around them— new ways of mapping nature, citizen science programs, greening schoolyards, etc.

[Washington, DC, officially joined the Biophilic Cities Network in 2016.]

What advice would you give to urban planners to create more sustainable cities?

There are many things we do to make cities more sustainable, of course: investing in bicycle and pedestrian infrastructure, as well as public transit, low or zero-carbon buildings and neighborhoods, and promoting a more circular metabolism for cities, among others.

We believe that the vision of Biophilic Cities will also help in important ways to make cities more sustainable and resilient. Providing more opportunities for urbanites to grow food, for instance, will advance sustainability but is also a biophilic strategy.

Green rooftops and living walls can insert important elements of nature.

At the same time, they help to contain storm water and reduce carbon emissions, among many other benefits.

Urban trees and forests provide habitat and urban nature while also moderating urban temperatures. Biophilia and sustainability can be achieved together!

What kinds of interactions have you had with other researchers, and urban design and planning practitioners you’ve encountered?

We are constantly interacting with other researchers and practitioners. Part of the excitement of exploring a new vision for cities—Biophilic design and urbanism—is to share (and test) ideas with colleagues at other universities and

cities. What works in one place may not work or be appropriate somewhere else, but there are always ways to learn and benefits to sharing.

One of the key lessons we have learned is that designing and building the next generation of cities will require collaboration between a host of different disciplines and professions—city planning, landscape architecture, civil engineering, urban ecology, public health, among many others. It is an exciting time for partnerships and new forms of collaboration.

What do you enjoy doing when you are not working?

Lately my family and I have been watching a lot of birds, though we by no means qualify as birders. We have enjoyed our Ruby-throated hummingbirds and are anxiously awaiting their return from the south (soon, we hope).

Family travel has been a major source of enjoyment—the Netherlands and recently Australia, where it has been possible to dovetail the professional and the recreational.

Is there anything else you’d like to add and share with our readers?

These are exciting times as well as daunting and challenging. I often choose to emphasize the hopeful and responding to major global challenges like climate change and biodiversity loss. There is the possibility of profoundly enhancing the quality of our lives and deepening a sense of meaning and purpose. There are so many ways that readers can become involved in creating this new world, so many ways of making a difference, professionally, and personally. We need your contributions and good work! o Responses edited for length and clarity.

Kelly Zheng is a junior multiplatform journalism major, with a minor in technology entrepreneurship, at the University of Maryland, College Park. This spring semester, she is an editorial intern at Washington Gardener.

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INSECTindex

Allium Leafminer

by Carol Allen

As our world seems to shrink and goods move rapidly and freely from one country to another, so do pests. Sometimes pests enter a new area attached to a plant they feed on, but often not. They can come into the U.S. on packing material and the boats and planes that transport goods.

One of the most fruitful places for Animal and Plant Health Inspection Service (APHIS) agents to search for these intruders is at military bases, where military family possessions are shipped in and out of the country. As an invasive pest enters, the new pest’s habits and locations are important information for gardeners to know.

In 2015, a new pest was identified in Pennsylvania. A grower in Lancaster County reported a complete loss of his leek and onion crop. Samples were submitted to the Pennsylvania Department of Agriculture Entomology Division for identification and the pest was identified as the allium leafminer (Phytomyza gymnostoma).

The allium leafminer is native to Europe and was first described in Poland in 1858. The insects found in Pennsylvania were the first reported in North America. It has since been reported in New York and New Jersey and is presumed to be in Delaware and Maryland, although there are no confirmed sightings as of yet.

This pest is a small fly, with adults ranging from 2.5–3.5 mm (less than 1/8"). Its color is matte-black with yellow markings along the sides of the abdomen and on the head. The adults emerge in the spring (mid- to late-April in 22

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Pennsylvania) and feed on various onion species. The females leave characteristic puncture wounds in a linear fashion along the leaf as they feed.

The eggs are laid on or in the plant and the larvae feed on tissue as they migrate to the base of the bulb to pupate. The white larvae can be 8 mm long as it nears pupation. The reddishbrown pupae (less than 1/8" long) can be found between the leaves, in the bulb, or in the ground near the base of the plant. Since there are two generations per year, there is another emergence of adults in September. This second generation feeds through the fall and then overwinters as pupae in the bulb or in the soil near the bulb.

The feeding damage done by the larvae in the lower leaves and in the bulb allows pathogenic fungi and bacteria to rot the bulb from the inside out.

Undetected larvae damage foreshortens storage life. In the garden, the leaves can be seen as twisted or distorted.

There are often multiple pupae per bulb.

The initial damage from the allium leafminer was found on leeks (Allium porrum), onions (A. cepa), green onions (A. fistulosum), and chives (A. schoenoprasum). Since then, nine out of 13 species of allium found in Pennsylvania have shown damage or the presence of the insect, including wild garlic (A. vineale) and garlic chives (A. tuberosum).

Ornamental allium species and cultivars are also susceptible, with damage having been observed on Allium Globemaster (A. giganteum).

The home vegetable gardener can cover onion plantings with insect-excluding mesh from before adult emergence in early spring to harvest. It should be

noted that perennial crops such as garlic chives can provide a constant food source and a repository for the pest.

Wild onions (A. canadense) would also serve as safe havens for the pest. Late plantings (May) could also be considered, although covering with a barrier would be necessary to avoid the second brood.

At this time, there are no specific biocontrols. There are several natural enemies in Europe and they have their counterparts here in the U.S., but there are no confirmed instances of predation on record.

There are some pesticides* labeled for leafminer control that would be appropriate. For the organic gardener, AzaDirect (azadirachtin) and Entrust SC (spinosad) are two of the available chemical controls. A more-complete list can be found here: http://ento. psu.edu/extension/vegetables/insecticides-labelled-for-leafminers.

If you think you see allium leafminer damage or the insect, contact your local extension service or master gardeners for confirmation. o Carol Allen describes herself as a committable plant-a-holic. She has more than 25 years’ experience in the horticulture industry, with a special interest in plant pests and diseases; is a Licensed Pesticide Applicator in the state of Maryland; and is an ISACertified Arborist. She can be contacted at carolallen@erols.com.

Allium leafminer photos are courtesy of Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org. *Please use pesticides safely! Read and heed all label directions!

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