CAF Seasons: Fall 2022

FALL 2022 BALTIMORE, MARYLAND

Malus, more commonly called crabapple, is a genus of about 35 species of deciduous trees from Europe, Asia and North America. These trees are beautiful with color and flowers in the spring, but in the fall season the trees’ fruit offers a glorious range of color to enjoy. Our collection, found on Vista Road, ranges from deep red to yellow “apples”. The fruits are bountiful at this time of year and attractive to birds.

"Autumn leaves don't fall, they fly. They take their time and wander on this their only chance to soar."

–Delia Owens, Where the Crawdads Sing

Welcome!

As I sat down to write this letter, waiting for inspiration, suddenly the scattered thoughts about what to say lined up. By coincidence I had attended a conference on conservation and the environment last week while Hurricane Ian crashed into the state of Florida, leaving millions without power and water. The climate deniers rallied, accusing NASA of admitting these storms were normal and just a simple act of Nature. Wrong.

In this Seasons we have a Q&A with Doug Tallamy. You’ll discover an interesting statistic that accompanies his response to the question of public land leading the way in conservation, creating habitat to sustain wildlife, planting for the future. An amazing percentage of land east of the Mississippi (greater than 85%) is privately held. Public lands (read parks and wildlife centers) cannot alone sustain the conservation effort. We as homeowners need to invest in native plants and trees to guarantee the planet for future generations. We hope that Cylburn Arboretum can be a place of inspiration for your future planting!

Meanwhile, the Nature Education Center (NEC) is well underway: soil appears in large piles one day and disappears the next. We are trying to plant as many trees as possible before the first frost to hit our target for replacing trees (the forest conservation plan) felled by construction of the NEC. For those of us heavily involved in this project, we see hope for the future everywhere. The goal is to help people discover what they can do to guarantee a healthy future for our woodlands and Nature in general.

Also in this issue, Fig brings a gardener’s perspective to the challenge of an intense forest conservation plan. We have a mandate to protect Cylburn’s surrounding woodland and cultivated garden spaces by offering a what, when and how approach to increasing the biodiversity of the property, again ensuring the viability of this treasured place. Lead by example.

There is a reason we refer to Mother Nature; Nature supplies what is necessary to sustain life of all kinds on this planet. We need to become sustainers and nurturers of the natural world. It’s hard to imagine a world without birdsong or buzzing. Thanks for all you do to support this effort.

Liquidambar styraciflua 'corky', or Sweetgum, is a large forest tree. Its common name refers to the aromatic gum that oozes from tree cuts. While this picture shows only some leaves changing color—as November progresses the tree becomes brilliant. The 'corky' cultivar is particularly interesting because the stems and bark look like cork.

Patricia Foster, Executive Director Cylburn Arboretum Friends

BOARD OF DIRECTORS

Rebecca Henry President

Nancy B. Hill

Vice President

Hilles Whedbee

Secretary

Robert A. Cook

Treasurer

Mariayne Brodnicki

Linda Wright Butler

Will Clemens

Beverly Davis

Emily Dillon

Alan Gilbert

Sandra P. Gohn

Mae Hinnant

Sorrel King

Maryellyn Lynott

Jo Middleditch

Ramesh Moorthy

Douglas Nelson Jack Owens

Nell B. Strachan

EX OFFICIO

Melissa Grim

Chief Horticulturist, Baltimore City Department of Recreation and Parks

Colleen Vacelet Owner, Intreegue Design

SEASONS is published by Cylburn Arboretum Friends

Written and edited by Patricia Foster Executive Director

Brooke M. Fritz Director of Development Erika Castillo Director of Education

Brent Figlestahler Head Gardener

Bill Geenen | Communication Design Layout and Design 4915 Greenspring Ave. Baltimore, MD 21209

Info@cylburn.org

Phone: (410) 367-2217 Cylburn.org

It became abundantly clear that our invasive plant problem was serious issue for insects (who can’t eat them) and for the birds who eat insects.” –Doug Tallamy

An Interview with Doug Tallamy

Doug Tallamy is the T. A. Baker Professor of Agriculture in the Department of Entomology and Wildlife Ecology at the University of Delaware, where he has authored 106 research publications and has taught insect related courses for 41 years. Chief among his research goals is to better understand the many ways insects interact with plants and how such interactions determine the diversity of animal communities. His books include Bringing Nature Home; The Living Landscape, co-authored with Rick Darke; Nature's Best Hope, a New York Times Best Seller; and The Nature of Oaks, winner of the American Horticultural Society’s 2022 book award. In 2021, he co-founded Homegrown National Park with Michelle Alfandari. His awards include recognition from The Garden Writers Association, Audubon, The National Wildlife Federation, Allegheny College, The Garden Club of America and The American Horticultural Association.

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The Cherry Scallopshell moth pictured above is just one of the 1,195 species of moths Doug Tallamay has photographed on his property in Pennsylvania. Photo Doug Tallamy

Cylburn Arboretum Friends:

What inspired you to study entomology and wildlife ecology? Then how did your research evolve into a focus on biodiversity?

Doug Tallamy: I was born loving nature and I say that seriously. I have a brother and sister who have the same background, same house and they’re kind of normal people. It’s not that they don’t like nature, but it doesn’t fascinate them, it doesn’t draw them in.

After an inspiring entomology course, I studied insect behavior for 25 of my 40-year career. Then we moved to a new house in Oxford, Pennsylvania. By the time we moved in the entire property was choked with invasive plants. It became abundantly clear that our invasive plant problem was a serious issue for insects (who can’t eat them) and for the birds who eat insects. I might have put it all together without moving but that was the catalyst.

CAF: We are an arboretum, so of course we have a focus on trees. The future Nature Education Center will have a focus on the “Hidden World” of trees. For example, people might not think of trees in relation to pollinators. Can you speak to the important role that trees play in the life cycle of pollinators?

DT: Everybody thinks of pollinators in terms of flowering herbaceous plants. Of course, most of our trees are flowering plants. For example, oak trees and cherry trees are host plants for butterflies—they create butterflies. A black cherry tree can produce 100,000 berries and every one of those berries was pollinated by an insect, so that provided a lot of pollen and nectar for those insects. Then there are trees like basswood that have specialist moth pollinators. Without the moth pollinator, you wouldn’t have the basswood. For every species of butterfly, there are 19

species of moths. Pollinators depend on far more than our flower bed.

CAF: How much of a plant is required to “make” a butterfly or moth? (How many leaves?) How many caterpillars does it take to “make” a bird?

DT: The only time I have seen a figure in terms of leaves required to make a caterpillar was with the spicebush swallowtail. It takes three complete leaves of spicebush to create the caterpillar that makes the butterfly. I ask people, can you spare three leaves of your spicebush to make a beautiful butterfly?

For a nest of chickadees, it takes 6,000-9,000 caterpillars just to get the chicks to the point where they leave the nest. After they leave the nest, they need caterpillars for another 21 days. If you add it all up, it’s tens of thousands of caterpillars to make one bird that weighs a third of an ounce.

“ For a nest of chickadees, it takes 6,000-9,000 caterpillars just to get the chicks to the point where they leave the nest.” –Doug Tallamy

Photo Doug Tallamy

CAF: You gave us permission to use your caterpillar data specific to the Baltimore area. This will go in a portion of our NEC exhibit called “The Woodland Sausage Cart.” What is it you would like someone to walk away with who is looking at this data set?

DT: I would like for them to sit and think: “Gee, if I put this tree in my yard, look at all the life I could create.” The tree will support the caterpillars, it will support the birds that eat those caterpillars, it will support the predatory insects that depend on those caterpillars, and it will support all of the parasitoids. That tree would literally support at least 1,000 species in a food web! It's like playing God.

CAF: We know you are a huge proponent of oaks. We are currently a part of a study on oak trees here at Cylburn in collaboration with the University of Delaware, University of Kentucky, and the US Forest Service. The study looks to advance the resilience of forests in cities,

and specifically the adaptive capacity of oak trees sourced from a climate gradient across climate zones. My question for you is: How should landowners think about what they plant (especially long-lived species like trees) in the face of climate change?

DT: The tendency is to take a southern tree and plant it farther north than its normal distribution because of climate change. I usually warn against that because climate change has really increased climate variability. We still get the cold snaps. Two years ago, there was a freeze that went all the way down into Mexico and even killed native plants that belonged there. If we start moving things farther north, the chances that they will suffer from climate variability are great. Generally speaking, I would plant the plants that have always been where you are, and I would focus more on matching soil type with the plant’s needs. For example, people say I want an oak tree. Well, there are oak trees that like acidic soil, there are oak trees that like basic soil,

there are oak trees that like bottomland, and there are oak trees that like rocky outcrops. I would match that rather than worrying about climate change.

As far as the diseases that are ravaging many of our trees, we need to find the trees that have some resistance. If 90% die, the 10% that live will be the future of our forests. If we stop planting species that are being attacked now, like oaks and beeches, we are never going to discover that 10% that are resistant, and then you lose an essential tree species. It’s the opposite of what most horticulturalists or arborists are suggesting. We’ve got bacterial leaf scorch on our property and I’ve already lost a red oak and two black oaks. But I've got several red oaks and black oaks that

are doing fine. They're the resistant ones that we need to favor.

CAF: What advice do you have for city dwellers with small (or no) yards or with limited economic means to landscape?

DT: If you have no money–start from seed that you’ve collected. I started most of the oaks on my property as acorns. That was 22 years ago and they’re now over 60 feet tall, so you don’t have to wait that long. You do have to go find the acorn and plant it and you’ve got to protect it from deer. If you have a tiny yard in a city, there are small trees you can plant. In the U.S., 82% of us live in cities, so you’ve got a lot of people with apartments or with no yard. If that’s the case, move to

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If we stop planting species that are being attacked now, like oaks and beeches, we are never going to discover that 10% that are resistant, and then you lose an essential tree species.” –Doug Tallamy

Photo Doug Tallamy

container planting. Let's say everybody in an apartment with a balcony had containers with fall asters in them. I saw this last weekend and it was spectacular. A migrating monarch would use those asters, even though they are in containers. Or bees, any of our 4,000 species of native bees will use native flowering plants that we put on our balconies.

CAF: Cylburn Arboretum is here for the citizens of Baltimore City. We try to show things you could do in your own yard and have a garden called City Backyards. Even with the best intention, sometimes planting an oak in a row home garden makes for a cramped situation. Would pollarding an oak negate its benefit to caterpillars? In other words, is an oak’s benefit correlated to its size and biomass?

DT: The benefits are in its leaves, for the most part, so if the oak is still making leaves

the caterpillars will use it. I am sitting next to a window and I am looking out at a Black cherry that grew up (I didn’t plant it) too close to the house. I went to cut it down two years after it started to grow and there were 11 tiger swallowtail caterpillars on it. I said, “I can’t touch that!” Then it got taller than the house so last fall I cut it down but left the stump and it came back as a cherry bush. It was heavily used by caterpillars with all the stems coming up. There were a number of Lunate zales and other caterpillars that were using it all summer long.

Let me make one request. Why don’t you call it city yards instead of backyards? People talk about backyard habitat and it implies that you can’t do it in your front yard, and it also implies it is so ugly that you have to hide it in the backyard. Neither is true.

“ All we have to do is put the native plants back” –Doug Tallamy

CAF: Our NEC will feature a teaching garden that demonstrates how a garden can be beautiful while also providing water management features and supporting wildlife. We hope these ideas educate and inspire people to bring these concepts back to their home gardens. Can you talk about your own message around Homegrown National Park and the issue of wildlife depletion?

DT: All we have to do is put the native plants back. As I said, our property was totally invaded! But we got rid of the multiflora rose and autumn olive and planted native plants. Then I started counting. I started taking a picture of every species of moth that is now making a living on our property and I'm up to 1,195 species so far and I am still counting. We have recorded 60 species of birds that breed here. So, can you reverse it? Absolutely, you can! If we put the plants back, we create the habitat our wildlife needs. That is the goal

of Homegrown National Park. The U.S. has parks and preserves, yet we’re in the sixth great extinction. Parks and preserves are not enough. We need to practice conservation outside of parks and preserves on private property. Seventy eight percent of the country is privately owned, and 85.6% of the country east of the Mississippi is privately owned. Without conservation on private property, we’re going to fail. For example, if we cut the amount of lawn in half, that would give us 22 million acres that we could put toward conservation. Everybody can be a part of Homegrown National Park. It’s simply a matter of recognizing that every square inch of the earth has ecological value and we need to treat it that way. We want to change the cultural relationship with nature as much as we want to actually restore land.

The future Nature Education Center Garden. Renderings and plan by Intreegue Design

Treeson:

Noun (Definition from Fig’s lexicon of Cylburn words) to counterintuitively destroy trees in the act of adding to or bettering an arboretum.

“The nonprofit admitted to treeson, for which they planted many new trees.”

An inconspicuous benefit of the NEC construction is the requirement to plant numerous mitigation trees here at Cylburn.

My preferred time to plant trees is Autumn. Personally, it’s a convenient time with predictable weather and a slow lead up to the spring and summer chaos in the landscape. Many trees are going dormant

for the year. Most root systems are not actively growing when ground temperatures dip below 50 degrees. Known as dormancy, this effect differs among tree species. Fall gives the nursery, gardener, or land manager

a splendid opportunity to sneak trees into hurricane season softened ground amid cooler temperatures.

The trees are given a chance to experience a winter's worth of moisture and frost action, which naturally settles a planting soil. Caution must be observed when the ground freezes amid winter's already desiccating environment. But these conditions are seen less and less here in Baltimore. Upon spring’s warming, trees can emerge from dormancy undisturbed, easing into that first summer of heat and stress. What’s more, in our Maryland climate the greatest intensity of rainfall will be captured beginning in March and peaking in July so that late fall planted trees have the greatest distance placed between them and the driest part of the year.

THE REQUIREMENT:

Survivability comes to mind when I think of many of our urban trees. What legacy do they leave and what legacy do they fall short of leaving. Last autumn, people gathered in the Inner Harbor to celebrate the legacy of William Donald Schaefer. He would have turned one hundred years old last November- a ripe old age for the river birch trees surrounding his metal cast likeness. In the 1990s, the ever controversial Schaefer, Governor this time around, put into motion the steps that would lead to the Maryland Forest Conservation Act of 1991. This legislation deals with forest conservation, protection, and reforestation primarily revolving around land development activity. Local jurisdictions enforce the accompanying regulations through the permitting processthe same process undergone by the Nature Education Center (NEC) project at Cylburn.

Now 31 years later on the eve of Schaefer’s birthday, CAF is required to mitigate for the removal of 138 inches of tree trunks and 28 inches of potential trees lost due to construction impacts. The rehab of the

Carriage House and construction of the NEC is clearly not without arboreal casualties. These 166 inches were calculated by a qualified forestry professional measuring the diameter at breast height of each tree larger than 8 inches. Invasive, those smaller than 8 inches, and dead trees are not counted toward the replanting requirement. Here, and in many other government interpretations, the reduction of the natural world into a point system is less than perfect. While the arithmetic is based on forest canopy, it is personally confounding that dead trees are valueless in this system, a 6-inch flowering dogwood doesn’t “count,” or even that thriving invasive canopy is also without any mitigation-worthy benefit. As is true of politicians like Schaefer and the construction process, neither is perfect. But, if asked in which season to plant a tree, Schaefer would most likely have said: “Do it now!”

Imbued with that level of enthusiasm, we’re excited to be required to plant trees here at the arboretum. Some of you may have noticed new trees added to our grounds over the past couple of years as part of our efforts. We have a couple more planting seasons to install our 166 inches. As you keep an eye out for new plantings, here is some of the thought process behind selecting and sighting all those trees.

THE STRATEGY: Breadth of Scope and Diversification of Collections

In general, our approach has been to spread the planting of young trees throughout Cylburn, in both the collections and our rapidly changing woodland. This approach ensures a distribution of diverse trees throughout the property and avoids one single collection being dominated by similarly aged and sized trees. In the woodland, our efforts ensure that voids in the canopy regenerate with desirable additions to the forest composition. By spreading planting

out over several years and planting nursery stock that ranges anywhere from one to three inches in caliper, we hope to diversify the rate at which our future collection canopy succeeds. To facilitate this goal our planting list is varied between understory, canopy, hardwood, and softwood plantings, each with somewhat different life expectancies. It’s also worth noting that our planting selection varies greatly in species. With few exceptions our new plantings are species or cultivars that we do not currently have at Cylburn.

Collection Succession

Since Cylburn’s collections vary so greatly, so does our proposed planting list. Broadly speaking, one of our planting goals was to add replacement trees to aging collections. In addition to growth, the past several years have seen a great deal of Cylburn removals too. Much of Cylburn’s collections are composed of trees planted around the same time and the same planting size resulting in glut patterned die-offs. One collection that we feel warrants addition is the Large Conifer Collection. This loose group of trees can be found throughout the property. Although now

in decline property-wide, these large, mostly evergreen, trees create year round visual divisions within the Cylburn landscape. It’s these evergreen curtains that shield the Small Tree Collection from the Maples, the Formal Garden from the East Lawn, and the Parking Lot from Mansion view. Many of them also serve as a greenhouse windbreak to boot.

Variation in Form

Another approach has been to consider canopy structure within our collections. One thing that makes the Cylburn landscape engaging is the varied forms of trees. We have consciously added trees to diversify viewsheds, such as adding the large textured Magnolia macrophylla on the East Lawn vista amidst trees with finer foliage or strategically adding colored foliage to the predominantly green viewsheds. Similarly, our Piedmont Woods planting at the property entrance is primarily composed of future canopy trees such as oaks and hickories. Adding structure to this portion of the collection meant planting a future understory and woodland edge suite of trees. In this way, the piedmont collection will be a collection of

trees and shrubs occupying different strata. On a macro scale, Cylburn is a great deal like an herbaceous perennial border. Additions should work among existing plants with considerations including care, aesthetics, and plant community.

THE LEGACY:

It’s fun to plan, source, and even plant all these trees. Their home at Cylburn will entitle them to a lifetime of care, stewardship and, hopefully, study. Few other trees in Baltimore City receive this level of dedication. Without our trees, Cylburn is just another park with a historic home associated with a wealthy dead person. That said, buildings can leave a legacy too. We have designed our building to complement a living legacy. Counterintuitively, the NEC subtly nudges visitors out the doors. Although an attraction in its own right, the NEC is designed to launch visitors out into the arboretum. We want folks to experience the ultimate legacy of Cylburn—her trees, gardens, and woodland.

The Atlas of the United States Trees is a delightful gift of the Federal Bureaucracy. The U.S Forest Service first published this gem in 1971. At that time, the USFS claimed 684 various species of trees grow in the continental U.S. According to the atlas, the location of greatest tree species richness is Liberty County, Florida. Incidentally, the quantification of this richness happens to be 138 species. Ironically, this is the same number of inches removed from the forest by the creation of the NEC. Interestingly, the total number of different species added to Cylburn via mitigation planting is projected to increase the arboretum’s collection biodiversity by 12-15%. Of the new trees, 60-70% are projected to be native to the Eastern United States. I have a suspicion that Cylburn might just become Baltimore City’s most arboreally biodiverse landscape— a legacy worth supporting!

So what is the legacy of these trees beyond lots of future tree care responsibilities and a boon to biodiversity? The potential of each tree lies in its ability to deal with climate change, its known or unknown benefits to the ecosystem, or maybe its Cylburn specific hybridized seeds peddled by future squirrels or caught in the Sinai Hospital winds. The saying goes, a tree planted today is hope for tomorrow. If any of the trees planted today become a family favorite, shade a proposal picnic, or memorialize a loved one, then our trees have fulfilled another important part of their legacy here at Cylburn—they have impacted the people of Baltimore.

WE ARE SO GRATEFUL TO OUR CAF MEMBERS.

Your membership directly helps us to support the Cylburn Arboretum through stewardship (think all of those tree plantings!) and educational programming (we have lots of monthly offerings for you to enjoy!). Entrance to the park is free but our work requires financial resources. We depend on your support to make this happen and we really appreciate you.

WAYS TO GIVE

DAHLIAS

We at Cylburn Arboretum Friends deeply enjoy growing and exhibiting dahlias. One of autumn’s most spectacular flowers, they exhibit amazing diversity in form and color. They belong to the Asteraceae family, which also includes zinnias, daisies, and chrysanthemums. Native to the highlands of Mexico and Central America, dahlias are treated as tender perennials in our Baltimore climate. We dig the tubers after frost each fall, store them for the winter and replant each spring for their glorious show in late summer and fall. If you did not get the opportunity to see them at Cylburn this year, some of the selections we featured are below.

1 Cherubino is a daisy-like bloomer with pure white petals circling around a bright yellow center. The delicate blooms are 4 inches in diameter. It is a collarette dahlia.

2 Robann Pristine starts as a bright white dahlia. As the flowers develop a slight lavender blush emerges at the center.

3 Vicki is a semi-cactus dahlia with a vibrant yellow color. The large blooms are 8-10 inches in diameter.

4 Pooh is a dahlia that pollinators seem to really enjoy. Orange blooms are outlined in yellow and take a collarette form.

5 Vassio Meggos is another of our very large varieties. With lavender pink blooms that are 9 inches in diameter—it is a showstopper. The petals taper to a point and curl as they arch back toward the stem.

6 Sissaroo is an extremely heavy bloomer. Flowers are about six inches in diameter. Bright pink blooms contrast nicely with a deep gold center.

7 NTAC Mia Li is a medium sized bloom with an unusual blend of peach, pink and gold. The color shifts with the season, darkening to a softer coral in the fall.

8 Robann Creamsicle is a tricolor orange, white, with whispers of soft pink large (5"+) informal decorative dahlia.

9 Crazy 4 Ieeshia is a formal decorative dahlia. The blooms are on the smaller size, only two inches in diameter. It is dark red but with a hint of yellow.

10 Hollyhill Black Beauty is a velvety dark red beauty with 6 inch blooms. It anchors our Dahlia demonstration garden on the east end.

11 Yankee Doodle Dandy produces large flowers of pink, white, yellow and mauve, each with a distinctive ‘collar’ of florets. This plant is compact and bushy.

THANK you to Nancy Blois, dedicated CAF volunteer and Dahlia garden caretaker.

THANK YOU