Northern Gardener - Summer 2025 by Northern Gardener®

R E ASONS TO G ROW A VE RT ICAL GARDEN

Gardener Northern

SUMMER 2025

HOMEGROWN

HEAT

GARDEN TO TAB LE

PRESERVING PEPPERS

How to spice up your garden GARDEN GREENER

Monarch Butterfly Magnets

TH IS SEA SON

Houseplant Summer Camp

A Resilient Garden Lovely Lady’s Slippers Back to the Land Display until Aug. 19, 2025

U.S. $8.99 Can. $9.99

Premium colored mulch, compost blends, and soil amendments for all your outdoor projects and landscaping

dakotaprairiecomposting.com | 952.233.9191 1 2 3 8 6 C H E S N U T B LV D . S H A K O P E E , M N 5 5 3 7 9 O W N E D A N D O P E R A T E D B Y T H E S H A K O P E E M D E WA K A N T O N S I O U X C O M M U N I T Y

Contents S U M M E R 2025 / VOLU M E 153 / NUMBE R 2

21 50

38 SEASONAL GUIDE 12 Houseplant Summer Camp 13 The Unkillable Weed 14 Shade Palettes 16 Carefree, Colorful Cacti 18 Ask the Expert 19 For the Love of (New) Lilacs 20 Garden Plan 21 Let’s Get Vertical 24 5 Plants that Attract

Hummingbirds

25 DIY Bee Water Station

GARDEN FOR GOOD

GARDEN TO TABLE

26 Abuela’s Mission

38 Homegrown Heat

GARDEN GREENER

42 Preserve Your Peppers

Garden-in-a-Box helps cultivate community and future gardeners.

28 Butterflies on the Brink You can help monarchs in your garden.

SPOTLIGHT 50 Back to the Land

A landscape architect gives his farmstead a sustainability makeover.

56 Minnesota’s Favorite Lady Dainty lady’s slippers have the power to charm everyone.

IN EVERY ISSUE 4 Editor’s Letter 61 Gardener’s Market 64 Growing Together

How to grow and process paprika and chili powder. Think beyond hot sauce when preparing homegrown chili peppers.

45 Farm to Fire

Two Minnesota chefs share their hottest recipes.

46 Bountiful Bells

Yes, you can grow sweet bell peppers in cold climates.

48 Secret Spice

What makes some brassicas bring the heat?

49 No Horsing Around

Rein in the horseradish, an aggressive-growing, kicky herb.

ON THE COVER Edible and ornamental Candlelight pepper plants are loaded with fruit (100+ peppers per plant!) and light up Meg Cowden’s Orono, Minn. garden. Photo by Meg Cowden.

SUMMER 2025 / NORTHERNGARDENER.ORG

THIS SEASON

Houseplant Summer Camp Will fresh summer air help your houseplants thrive? Yes, absolutely. But consider these pros and cons before sending your precious houseplants to camp on the patio. With some care, your plants can enjoy the summer outdoors and come back in as healthy and lovely as ever. STO R Y A N D P H OTO S M A RY L A H R S C H I E R

PROS

CONS

You will need to harden off plants as they go outside. Wait until nighttime temperatures are safely in the 50s to move plants. You must give them the correct light or they will struggle. Succulents and cacti can take full sun, but most houseplants like dappled shade or morning sun. If the sun is too bright, leaves will burn. If plants are large, such as citrus trees, moving them in and out can be a challenge. Fall cleanup is essential. Clean pots and plants thoroughly with soap and water. Once inside, watch for fungus gnats, which lay eggs in soil. Make sure the soil is not too wet before bringing plants indoors, and stock up on the yellow sticky traps to prevent an infestation from getting out of control.

SUMMER 2025 / NORTHERNGARDENER.ORG

B OT TO M P H OTO : B E R N A R D H E R M A N T O N U N S P L A S H

Once outdoors and in proper light, plants will grow quickly, making them lush and lovely when they come back inside. Some may even bloom. Outside, it’s easy to fertilize them, repot and deal with diseases and pests that may have surfaced in winter. Just be sure to use a non-systemic product, such as horticultural oil or insecticidal soap. Nature helps with rainwater, which has the perfect pH for plant growth, and air circulation, which mitigates fungal diseases. Beneficial insects outdoors can help control pests, such as scale or mealybugs. Finally, houseplants add a tropical flair to your outdoor spaces and having them outside gives you a chance to dust all the shelves where they usually live.

THIS SEASON

The Unkillable Weed Sure, it looks like a hosta flower—but this invasive bellflower is a creeper, not a keeper. STO R Y A N D P H OTO S JENNIFER RENSENBRINK

t thrives in sun. Shade, too. Sand, salt and clay? No problem. And if you try to pull it out, it laughs in your face. My south Minneapolis yard and neighborhood are riddled with this monster: creeping bellflower. I’ve been on a journey with this plant that many gardeners can relate to, from “oh, that’s pretty!” to “this plant is the bane of my existence.” Native to Asia, Campanula rapunculoides was sold for many years in the U.S. as a garden plant. I can see the appeal—it grows anywhere, is nearly impossible to kill and has pretty purple flowers. These days, it’s considered invasive in the state of Minnesota. What makes creeping bellflower so impossibly hardy? The roots. If you try to simply pull it out, slender roots near the surface of the soil will break off. Unfortunately, the tuberous rhizomes that make up the critical part of the root system will still be underground, and they will send up new shoots almost overnight. Those tuberous roots also make the plant virtually drought-proof.

Control options

I dig up the plants with a shovel, but I’ve never been able to completely eradicate them despite trying for 10plus years, likely because they are so prevalent in my neighborhood. To battle bellflower, dig at least 8 inches deep all the way around the plant to loosen the soil. Gently turn over the clump and

The story of this plant’s resilience is in its roots.

carefully tease out the tubers and fine roots. Try to get them all. Do not throw pulled bellflower plant parts into your home compost—it will not get hot enough to kill them. Bag and toss them in the garbage or, better yet, burn them. Herbicides like glyphosate kill creeping bellflower, but most require multiple applications as the roots continue to resprout. The University of Minnesota Extension recommends clopyralid, dicamba or triclopyr, but with these and all herbicides it’s critical to follow the instructions on the label to avoid harming yourself or non-targeted plants, such nearby trees and shrubs. Use the bare minimum amount necessary and remember, the label is the law.

I like to dig mine in May, when the ground is softer and it’s easier to pop another perennial in the spot where I removed the bellflower. Identifying it in early spring takes some practice, but once you dig it up and see the tubers, all doubt will disappear. When it first appears, it has heart-shaped leaves with hairy undersides and coarsetoothed edges. If you can’t dig it out, pulling it in mid-summer before it goes to seed is better than letting it spread unchecked. Some gardeners successfully smother the plant under a plastic tarp, but you have to leave the material down for an entire growing season. Another irritating bellflower trait? It’s confusingly similar in appearance to desirable native varieties, such as American bellflower (Campanula americana) Identification and harebells (Campanula It’s easiest to identify rotundifolia). Native creeping bellflower when Identify creeping varieties aren’t nearly as it’s in full bloom in late bellflower by its small, widespread, so if you notice summer. Find any unkempt purple flowers. yard or alleyway and you will purple, bell-shaped flowers see the small, purple, bellin late summer and you shaped flowers everywhere. Get rid of don’t remember planting them, it’s it before the flowers go to seed—each probably creeping bellflower. plant is capable of producing more than 10,000 seeds.

NORTHERN GARDENER / SUMMER 2025

4 WAYS TO

STORY AND

PRESERVE YOUR

ILLUSTRATIONS

HOMEGROW

TAYLOR

CHILI PEPPERS

TINKHAM

had five big bottles of homemade hot sauce in my refrigerator a couple years ago. I had just started growing a wide variety of chilis and was overwhelmed by how many each plant produced. Hot sauce was an easy way to burn up a big batch of peppers; let the chilis sit in vinegar for a few days, blend them up, strain the mixture, bottle it and done. The problem? Even the biggest spicy food lovers only go through a small amount of hot sauce in a day. I was drowning in sauce, and it wasn’t versatile enough. And so began my quest to find new ways to preserve chilis. I cook spicy food almost every day and am proud to say I haven’t purchased a grocery store chili pepper in years. I’m sharing a few of my favorite preserving methods, and I hope you find a couple of recipes or techniques to try. Come midwinter, you’ll be grateful when your chilis are bringing the heat.

SUMMER 2025 / NORTHERNGARDENER.ORG

METHOD

DRYING & DEHYDRATING With a combination of warmth, air flow and low humidity, you can safely dry foods at home. Hang drying peppers is the easiest method, requiring only string and a needle. Most northern climates are too humid for sun drying, a technique famously used in the Mediterranean for sun-dried tomatoes. Instead, we northerners hang dry chilis in a wellventilated spot out of direct sunlight. Using heavy thread and a large craft needle, pierce peppers at the stem base and hang the loaded string in an attic window, screen porch or dark, ventilated pantry. Thin-skinned peppers like habanero, Thai chili and cayenne are best for hang drying. Using a dehydrator to dry whole chilis takes a painfully long time, so I cut the stems off and slice the chilis in half. I set my dehydrator to 140 degrees Fahrenheit and, depending on the type of chili, humidity level and how many peppers you pack into the dehydrator, they can take anywhere from 8 hours (thin-skinned chilis) to 12+ hours (thick-skinned) to dry fully.

PRESERVE YOUR PEPPERS

METHOD

PICKLING

Pickled chili peppers are a treat in sandwiches and salads and as a topping for soups, pizza and nachos. Slice peppers into rings or cut them in half after removing the stem—I like to make a few jars of each. If you prefer less heat, remove the seeds and membranes before pickling. The best chilis for pickling have thicker skins; think jalapeno, serrano, Fresno, banana and Cherry Bomb.

PICKLED PEPPERS RECIPE For about 5 pints of basic pickled peppers, you’ll need: 3 lbs hot peppers 6 cups white vinegar 3 cups water 2 ½ tsp pickle crisp (optional, but nice) 2 ½ tsp canning or pickling salt (optional, but nice) 5 pint-size jars with lids and rings To process peppers: 1. Prep chilis by either cutting them into ½-inch rings or slicing them longways down the middle and removing the stem. 2. Combine vinegar and water on the stove and boil for one minute. 3. Pack each jar very tightly with pepper rings or halves, then add ½ tsp pickle crisp and salt to each jar, if using. 4. Add hot vinegar mixture to each jar, leaving a ½ inch of headspace. 5. Process in a water bath canner for 10 minutes. Learn canning basics at northerngardener.org/ food-preservation-basics

RED ALERT An important reminder when working with chilis: always wear gloves, avoid touching your face or other parts of your body after processing them and work in a well-ventilated area, especially when processing dried and powdered products.

METHOD

FERMENTING

There are two fermented pepper products I cannot get enough of: sliced jalapenos and chili pepper paste. For sliced jalapenos, I fill a jar with as many slices as I can fit, cover them with a 3 percent salt brine, use a weight to keep the slices under the brine, close the jar with a pickle pipe or airlock lid and leave it out in a dark place until the slices are bubbly and funky. Then I store them in the fridge and put them on tacos and sandwiches. For the paste, I follow the same process, but when they’re done fermenting I blend them up, pack the paste into a jar and top it with a little reserved brine. I like using the paste in sauces, dressings and even in soups and stews.

A RAINBOW OF PEPPERS Harvest peppers regularly when they are mature size. You do not need to wait for all varieties to turn red before harvesting— many varieties (jalapenos, Thai chilis and even cayenne) are just as delicious when green. The plant will continue to produce flowers and fruit while you harvest. PICK YOUR PEPPERS Generally, the smaller the chili, the more of them you’ll harvest. Small chilis like Thai dragon, cascabel and Chilis de Arbol will yield a large harvest. Larger chilis (hot Hungarian wax, poblanos and Anaheim) will produce a more moderate harvest. SOME LIKE IT HOT Like it super spicy? Try habanero, ghost peppers or scotch bonnet. Hoping for something milder? Try Cubanelle, poblano or pepperoncini. If you’re looking for medium spice, try Fresno, cayenne or serrano.

NORTHERN GARDENER / SUMMER 2025

Minnesota’s Favorite Lady

SUMMER 2025 / NORTHERNGARDENER.ORG

The lady’s slipper— a native pink and white orchid wildflower —has the power to charm everyone. STO R Y A N D P H OTO S MICHELLE MERO RIEDEL

NORTHERN GARDENER / SUMMER 2025

MINNESOTA’S FAVORITE LADY

“C. reginae is best enjoyed in the wild,” says Gardens of Rice Creek owner Betty Ann Addison.

t’s a rare sighting. I caught my first glimpse decades ago while photographing a wedding. The elusive lady’s slippers were growing under a grouping of shade trees. I will never forget the enchanting scene; I felt like I was in a fairytale and hoped that someday I’d grow these beautiful ladies, too. Years ago, a friend gifted me a mail-order plant consisting of one shoot (stem and roots). The first year I saw one flower. The second year, three flowers. From there, it just kept growing. The plant is finicky, as it doesn’t fit into every cool-weather garden location. The lady’s slipper is best suited to the advanced gardener, but hopefully I can provide you with enough information so you, too, can grow this delicate plant. Commonly called the showy lady’s slipper, Cypripedium reginae is also called the pink and white lady’s slipper.

Forty-three orchid species grow in Minnesota—C. reginae is one of them, though scarce and endangered in the wild. Seed-grown plants are available from nurseries (see pg. 54 for specifics), and they take up to 15 years to bloom for the first time.

Tale of the lady

It’s been 123 years since the pinkand-white lady’s slipper became the Minnesota state flower. Due to opposing opinions, she almost didn’t get her affirmation. The dandelion almost got the vote. An opposer to the lady’s slipper thought the state flower should be common and popular. But who wants a prolific weed to represent Minnesotans? In 1893, The Woman’s Auxiliary Board endorsed the lady’s slipper as the state flower. The women, not persuaded by the dandelion recommendation, pushed their preference through the legislature. The bill was finally passed in 1902.

SUMMER 2025 / NORTHERNGARDENER.ORG

Protected property

In the early 1920s, overexploitation of the lady’s slipper nearly destroyed its foothold. The plant takes about 15 years to blossom, and people were concerned it would go extinct. In 1925, it became illegal to sell the lady’s slipper unless the secretary of state granted special permission.

Vision of blooms

View Minnesota’s state flower blooming in its natural habitat at these locations: » The Eloise Butler Wildflower Garden in Minneapolis hosts a dramatic showing of them early to mid-June. You’ll find them along Lady’s Slipper Lane. Free admission. » If a road trip entices you, check out the Lady Slipper Scenic Byway, a 28-mile country drive between Blackduck and Cass Lake in north central Minnesota. The ladies bloom from late June to early July.

MINNESOTA’S FAVORITE LADY

Fairytale Features Lady’s slipper is a rare perennial, coolweather orchid that grows in USDA Hardiness Zones 2-7. Bloom time is May through July, depending on your zone.

One of the plant’s most notable features is the pouch, a distinctive, vividly magenta-pink slipper that protrudes out, topped with white petals and sepals. Each stem can hold one to three flowers. Each flower lasts about two weeks.

Leaves are broad, oblong, ribbed and hairy with a velvet sheen. Each stem holds about three to five leaves.

Most of the plants I’ve seen are 2- to 3-feet tall while in bloom, but they can grow as tall as 4 feet in the right setting.

NORTHERN GARDENER / SUMMER 2025