Beyond Broccoli Part Five: Love Them and Leaf Them

Welcome back to Beyond Broccoli, the brassica blog series! You can find previous entries here. In this edition we’re going to explore the plants in the genus Brassica that are grown for edible leaves.

I think the best place to start is on the shores of the Mediterranean. This is likely the home of the wild relatives of what became the domesticated forms of Brassica oleracea. They would have looked something like what we know as kale. The lineage of these wild plants is still fairly obscured, but if you want to read more about it check out this scholarly article.

The kales we grow today are actually not all one species. Most of them are Brassica oleracea var. acephala(or Acephala Group), but the super-hardy kales like Red Russian and Siberian are Brassica napus var. pabularia, related to rutabaga. Even the B. oleracea kales are amazingly varied, having been bred for millennia into forms with curly leaves, flat leaves, small or enormous leaves, leaves with blue and purple tints, the cabbagey-looking ornamental kale that landscapers plant at the corner to carry through the winter, and kale that forms stems taller than people that are made into walking sticks. (I wish we could grow that kind here, but our heat and humidity don’t agree with it. At least you can read about it.) My favorite kind to grow and eat is the blue bumpy type known as Tuscan, Lacinato, or Dinosaur kale.

Looks like dinosaur skin, I guess? Kid- and adult-friendly!

I’ve never been a kale-massager, so I prefer softer leaves that could be eaten in salad but also cook up quickly. Also, remember kale chips? Still fun, even if less trendy.

Maybe kale is over now and collards are the new cool veg. I posted a couple of years ago about the Heirloom Collard Project, and I’m noticing that these varieties maintained by seed savers are starting to make their way into seed catalogs. I’ve been growing Yellow Cabbage Collards for the last couple of years, and I really like the tender pale leaves with bittersweet flavor that have held well for me in the freezer (after steaming) waiting to be put into a soup or sauteed with a little bacon.

Yellow Cabbage Collards in the garden and on the counter with full color developed

What are collards and how are they different from flat-leafed kale? The distinction is difficult and sometimes more culturally-based than anything else, but collards have been broken out from the Acephala Group into their own Viridis Group. They tend to be both cold-hardy and hold well in the heat, though that varies depending on cultivar.

Similar to both kale and collards is Brassica oleracea var. costata, known as Portuguese kale, tronchuda, Portuguese cabbage, or sea kale (which is also the common name of another plant, Crambe maritima, also in the Brassicaceae family). Tronchuda is a decorative plant with broad white ribs in large green leaves, used for traditional soup recipes, that is not very cold-hardy but can take summer heat (up to a point). I recommend trying it if you’re an adventurous gardener!

Let’s step back for a moment and think about plant evolution. Wild leafy plants developed into the wide range of forms the Brassica genus encompasses today in two ways: natural mutation, and breeding by human farmers. What that probably meant was that people gathering or growing the plants spotted a mutated form, thought it had value, and collected the seeds to grow more of it, gradually refining the new trait. One of those traits must have been the tendency for leaves to curl in on themselves and form a head. Those heads would have been loose to begin with, and only over time and through breeding became what we now call cabbage.

There are two kinds of cabbage that have completely separate origins: the European cabbage, Brassica oleracea var. capitata, and the Asian cabbage, Brassica rapa subsp. pekinensis. Depending on your cultural background, you may regard one of them as cabbage (or choy) and the other as an interesting foreign dish, but they’re really not that different: both leafy vegetables that developed into a heading form. European cabbage tends to be more tightly-formed, with a firm head surrounded by more open leaves that spread out widely. This is a big plant, which we don’t always realize when we buy the head in the market, and needs to be widely-spaced in the garden.

Cabbages in the garden

There are a bunch of types (red, savoy, and green/white in various shapes). I suggest concentrating on the modern quicker-growing varieties for spring, especially those with smaller heads, and the hardy storage types for fall. The tight heads mean that caterpillars and other pests don’t penetrate to the center, but they will make a mess of the outer leaves and often the bottom of the head, so row covers are still a good idea. Heavy rains can cause the heads to split, and rollercoaster temperatures can make the plant give up and bolt before heads form. But they are very fun to grow when all goes well!

Asian cabbage, generally known as Chinese or napa cabbage (“napa” is from Japanese for leaf vegetable), is usually somewhat quicker-growing than its European equivalent, but less tolerant of cold early spring temperatures when it’s young. It may be better grown in fall. Even the types that form a strong head are still somewhat open-leafed, and pests seem to love them, so row cover is a real plus. There are a huge number of varieties, but most seed catalogs (except those that focus on Asian crops) only stock one or two. Start with these and then branch out!

Cabbages of all sorts have a vast literature of recipes attached to them, from coleslaw to sauerkraut to kimchi. It’s the ancient storage vegetable, whether you’re talking about cellars or fermentation crocks, but of course it’s also great for a quick salad or stir-fry.

I can barely touch here on the world of Asian leafy greens, from the semi-heading bok choy and tatsoi to the loose-leaf komatsuna, chijimisai, and Tokyo Bekana, a kind of Chinese cabbage that looks like lettuce.

Tokyo Bekana

Most of these are Brassica rapa subspecies, but senposai, a loose-leaf green with huge leaves, is a hybrid of B. rapa and B. oleracea. These plants all hybridize very easily, across and between species, so there’s always something new growing out there. I strongly suggest trying a few Asian greens in your garden, even if you didn’t grow up eating them. Most of them grow speedily, which is an advantage in our uncertain weather and changing climate, and they can be used in a wide variety of recipes. The flavors range from spicy to bland and the textures from delicate to crunchy; there’s something for everyone.

Asian “mustards” like komatsuna and mizuna are the spicier end of the B. rapa rainbow, but the term “mustard” more often applies to plants in the Brassica juncea species. There are subgroups in the species with differing origins throughout Asia. I’m most familiar with growing the broad-leafed varieties such as Green Wave and Red Giant, but there are lots of fun ones with fancy feathered leaves and combinations of colors. If you like spice in your life, throw some mustard seed in with your salad mix or grow it to its full size (which is pretty big!). Mustard is tolerant of summer heat longer than a lot of greens (or, um, purples) and it deals with chill well too.

I shouldn’t have left the world of European cabbages without touching on the weird cousin—what’s up with Brussels sprouts? Somehow I always thought this plant with a tall stem and leaves like kale, but which grows tiny cabbages in its leaf axils, must be a modern invention, but in fact it’s been grown in Europe (including but not exclusively in Belgium) since at least the 13th century. It’s just emblematic of the strange ways brassicas develop. Sprouts are not the easiest plant to grow here, because they need a long season of cool weather, but if you can get them going in late summer they will deal fine with the cold and give you a harvest in December. They are terrific roasted; do not boil them to death and they will reward you. Or slice them thin and use them in salads. Oh, and speaking of strange brassica developments: I have not grown Kalettes® but look them up for fun—they are a cross between Brussels sprouts and kale, and look exactly like what you are imagining.

Next month, Beyond Broccoli will literally start with broccoli and go beyond. We’ll be talking about edible flower buds and related structures in the genus Brassica. Back in July for our final chapter. Hope you’re harvesting some brassicas right now as we head into summer!

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

Be Proactive to Prevent Vegetable Diseases

When it comes to vegetable diseases, an ounce of prevention is worth a pound of cure. Many diseases can be stopped before they start with smart garden practices.

Spring rains cause spots, dots, and fuzzy blots to pop up in everyone’s vegetable patch. That’s fungi having fun. But whether our weather is wet or dry, fungi, bacteria and viruses stand ready to harm plants. 

So, how do you keep them at bay? Be informed and watchful. Look at your plants often to spot small problems before they get big and use the following tips to prevent disease problems.

If you have repeat offenders – diseases that show up year after year – look for disease-resistant varieties. For example, there are varieties of tomatoes labeled as resistant to both verticillium and fusarium wilt. 

Early blight is a common disease of tomatoes. Photo:  J. Traunfeld, UME

Some plants are available in certified, disease-free starts. Choose potato tubers, garlic bulbs, and asparagus and rhubarb crowns that are certified and disease-free. 

Vegetables hate soggy soil. If your garden area is wet, consider creating a raised bed to improve drainage. Or, grow in containers or move the garden to an area that drains well.

You’ve heard me preach the gospel of compost time and again. But did you know that compost actually discourages some plant diseases? Garden smart by adding compost every year. 

Help prevent disease by spacing your plants properly to encourage good air circulation. Plant labels often give spacing tips as do garden books and websites.

Warm, humid weather invites powdery mildew on squash. 
Photo: UME Home & Garden Information Center

Rain can spread soil-borne diseases, splashing infected soil up on plants’ leaves. So keep your soil covered with an organic mulch such as untreated grass clippings or newspaper covered with straw.

Fungi love wet leaves, so water wisely. Water at the base of the plant using soaker hoses or drip irrigation. And water in the morning, not the evening, so leaves dry before nightfall. 

Practice tough love. Remove infected leaves or pull entire plants if they become badly infected. It’s better to lose one bad plant than the whole row. Don’t compost sick plants: bag and trash them.

Overripe vegetables invite disease organisms. So, harvest your vegetables before they get mushy. 

A thorough cleaning of your vegetable bed at the end of the season is crucial since many diseases can overwinter in the soil. Again, if anything had a serious disease issue, bag and trash it.

If you spot a problem, e-mail your local Extension horticulturist a photo or bring them a sample to identify. Here’s a list of our county offices. We can usually get back to you in a day or two with advice.

For other growing tips and diagnostic help, visit our Home & Garden Information Center website. It has photos, management tools, and a wealth of resources. There’s even an Ask Extension link to submit gardening questions to certified horticulturists.

Enjoy your vegetable garden this year. A few seeds and transplants, some rain, sun, and a watchful eye will have you enjoying fresh, healthy homegrown food all season long.

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension. This article was previously published by Herald-Mail Media. Read more by Annette.

This article was previously published by Herald-Mail Media.

Nurture Natives: 4-Hers Take a Stand to Protect Maryland’s Ecosystems, Economy, and Agriculture

This is a guest post by Esther Bonney, a student in Charles County, Maryland, and a member of the University of Maryland Extension 4-H Program.

Invasive plants are detrimental to Maryland’s well-being, and their damaging effects are becoming more evident each year as we witness declines in crop productivity, reductions in pollinators critical to maintaining stable ecosystems, and widespread displacement of native habitats. Between 2008 and 2013, wild bees declined by 23 percent across the U.S.—a serious concern to farmers and consumers alike. Through educational programs, guides, and native giveaways, Nurture Natives is taking a stand against invasive species to protect native plants and pollinators, restore natural habitats, and support farmers. Nurture Natives is led by University of Maryland 4-Hers Esther Bonney and Samantha Rutherford and Extension 4-H Educator Amy Lang and UME Charles County Master Gardener Marlene Smith. 

people line up for native trees at Maryland Day
Visitors line up for native trees at Maryland Day, stretching down the courtyard and around the sidewalk, sometimes longer than the line for free ice cream!

In March 2022, our team was selected to attend the National 4-H Youth Summit on Agriscience. There, we developed our project, Nurture Natives, to address a prevalent agricultural issue in our community: invasive plant species. Invasive plants choke out native species and are a major cause of crop loss and food insecurity. Invasive trees such as the Tree of Heaven rapidly overtake farmlands and attract invasive pests such as the Spotted Lanternfly, which is a serious threat to grape crops. In the U.S. alone, invasive species cause $40 billion worth of production losses to crops and forests per year. 

Nurture Natives is dedicated to increasing biodiversity through the planting of native trees and the eradication of invasive plants. In the past year, Nurture Natives has been featured on the National 4-H and University of Maryland Extension websites, won a Lead to Change Grant, and was selected by the National 4-H Council as one of two projects nationwide to receive the highly-competitive Scale for Success Award. Nurture Natives was also recently featured in the Southern Maryland Independent: Nurturing natives and the next generation of environmental scientists

Our team began our work by educating and raising awareness about invasive species in our community of Charles County. We hosted educational programs at schools and camps and, in October 2022, partnered with eight local organizations to host the first annual Nurture Natives Giveaway. We hosted games, crafts, presentations, and a honey-tasting to showcase the importance of native species and pollinators. In just two hours, we distributed 150 native trees and shrubs and reached over 70 families. 

Our team recently published Nurture Natives, a guide to the native alternatives of 12 invasive yet highly-popular ornamental plants, including the Bradford pear and burning bush. Take a look at the online version of our guide here: Nurture Natives (PDF). We are currently distributing hundreds of our guides to nurseries across Maryland. Through our guide, we hope to educate homeowners on the harmful impacts of invasive species and encourage more native purchases. We are also working on publishing an expanded version of the Nurture Natives guide by August 2023. 

The Nurture Natives display at Maryland Day
The Nurture Natives booth at Maryland Day showcased a variety of outreach and education materials, including tri-folds, flyers, and guides.

On Saturday, April 29, our team made a splash at the University of Maryland’s Maryland Day! We ran games, crafts, activities, and an information table, in addition to distributing 400 free native trees and shrubs in just 2 ½ hours! The line for the trees stretched down the courtyard and around the sidewalk, at times even longer than the line for free ice cream! Our team had the incredible opportunity to share our journey and mission with hundreds of Marylanders and the University of Maryland faculty, including Dr. Craig Beyrouty, Dean of the College of Agriculture and Natural Resources. We were thrilled to see so many people getting excited about native species and taking action to support them. 

Esther and Marlene speaking with the Dean of the College of Agriculture and Natural Resources
Esther Bonney and Marlene Smith speak with Dr. Craig Beyrouty, Dean of the College of Agriculture and Natural Resources at the University of Maryland, about the Nurture Natives journey.

Our Nurture Natives team is passionately working to protect Maryland’s native species. Our recent success at Maryland Day is only the beginning. We are working with legislators to pass a law prohibiting the propagation, importation, selling, and purchasing of the Callery pear in Maryland. The Callery pear tree (Pyrus calleryana), a non-native species from Asia, was one of the most popular ornamental trees in the U.S., with various cultivars, including Bradford pear, Aristocrat, and Cleveland Select. However, the MD Department of Agriculture now recognizes the Callery pear tree as an invasive species in Maryland due to its rapid growth, prolific seeding, and ability to outcompete native plants, wreaking havoc on our state’s biodiversity, agriculture, and economy (MDA). The tree’s invasive traits and probability of causing environmental and economic harm have led three U.S. states to prohibit its cultivation (Morning Ag Clips). 

Esther with the Governor and Lt. Governor
Esther Bonney speaks with Governor Wes Moore and Lt. Governor Aruna Miller about the Nurture Natives journey.

Follow Nurture Natives on Facebook to stay updated on our journey and future events (including free tree giveaways)!

Esther Bonney, a sophomore in high school and dual enrollment student at the College of Southern Maryland, is actively working toward a brighter and greener future for Maryland. Recognizing the urgent need to address the decline of local biodiversity, Esther founded Nurture Natives as a platform to engage youth in environmental initiatives, with a specific focus on planting native trees and eradicating invasive plants. Esther was recently selected as a 4-H Youth in Action 2023 Finalist for her work within 4-H and with Nurture Natives. Esther plans to pursue a career in environmental law, where she can continue her advocacy and drive transformative change on a larger scale. Alongside Nurture Natives, Esther enjoys playing the violin and caring for her five goats.

Grow It Eat It Celebrates 15 Years of Teaching and Promoting Food Gardening!

Food gardeners are an important part of any local food system. In Achieving Sustainability through Local Food Systems in the United States (PDF) (2013), agricultural economists Dale Johnson and James Hanson, Ph.D. state: “By far the greatest, but often overlooked, local food source in the United States is gardening.”

About 35% of Maryland households are doing some type of food gardening and have lots of important questions: What’s this worm eating my kale? How do I improve my soil and test it for lead? How do I start a school garden? Where can I take a vegetable gardening class?

Since 2009 many residents and communities have received science-based food gardening answers and help from Grow It Eat It (GIEI)– one of the six major sub-programs of the University of Maryland Extension (UME) Master Gardener Program that teaches and promotes home, school, and community food gardening. This article serves to introduce this amazing program and some of its successes. I plan to write a second article later this year on some of the exciting 2023 GIEI projects from around the state.

What is GIEI?

Grow It Eat It was developed late in 2008 by UME staff, faculty, and volunteers in response to the Great Recession. Many people were already interested in trying their hand at food gardening as a way to eat more fresh produce and connect with nature. The economic collapse forced folks to find ways to reduce household expenses.

The main GIEI objective has been to increase local food production by combining the power of grassroots education and technical assistance delivered by field faculty and Master Gardeners, with UME’s digital gardening resources. Master Gardeners (MGs) have taught hundreds of classes, developed demonstration gardens, and helped thousands of individuals and groups start food gardens and learn and use best practices. Residents can learn about GIEI classes and events by visiting their local Extension web pages and connecting on social media. MGs also help residents solve food gardening problems at Ask a MG Plant Clinics around the state. The Home and Garden Information Center (HGIC) supports GIEI by training MGs, creating and maintaining digital resources, and answering food gardening questions through the Ask Extension service.

GIEI intersects and collaborates with other MG sub-programs– Bay-Wise Landscaping, Ask a MG Plant Clinic, Composting, and Pollinators– and with UME’s nutrition, natural resources, youth development, and urban ag programs. This helps the program address four of the five Strategic Initiatives guiding the College of Ag & Natural Resources.

5 strategic initiatives of the University of Maryland Extension College of Agriculture and Natural Resources

As the faculty lead, I have loved every minute spent working with UME faculty, staff, and volunteers to shape, improve and expand the program. Master Gardener Coordinators and Volunteers decide how to best shape GIEI to meet local needs. The State MG Office organizes regular GIEI statewide planning/sharing meetings and continuing education classes, and provides seeds, teaching, and marketing materials. MGs responded to the pandemic by moving GIEI classes online. GIEI projects and activities steadily increased in 2021 and 2022 and should surpass pre-COVID levels in 2023.

packets of sunflower and green bean seeds
75K seed packets have been distributed to residents to promote food gardening and the UME MG Program. Sunflower and bean seeds in 2023!

Program Outcomes and Impacts (2009-2022)

  • 121,894 MG volunteer hours valued at $3.05M
  • 1,832 classes and workshops for 47,000+ residents
  • 70 tons of produce grown in MG demonstration gardens donated to local food banks and pantries
  • 87 MG advanced training classes on Vegetable Plant & Pest Diagnostics, Hydroponics, Community Gardening, Youth Gardening, Organic Gardening, and other topics
  • Hundreds of web pages, videos, and blog articles
  • Awarded “UME Signature Program” status in 2017
  • Technical assistance and support for dozens of community and school gardens
  • “Year of…” initiative featuring a different crop or vegetable family each year. 2023 is the Year of Sweet Potatoes!
  • Inspired Shauna Henley, Ph.D. to create Grow It, Eat It, Preserve It
  • Inspired the Bay-Wise Landscaping Program to create a Food Gardening Yard Stick (PDF)
  • Evaluation data:
    • 2009-2011 statewide survey of GIEI classes taught by MGs (n=2,532). When asked “Why do you want to start a vegetable garden?” 77% selected “to contribute to a more healthy diet” and 65% selected “to save money on food costs”
    • 2009-2011 6-month follow-up statewide survey of GIEI classes taught by MGs (n=349). As a result of taking the class, 36% started a vegetable garden, 37% became more confident gardeners, and 31% increased garden productivity
    • 2009-2010 statewide follow-up survey of the GIEI website (n=858). “Made my garden more productive” (44%); “Made me a more confident gardener” (40%); “Started a vegetable garden” (31%)

GIEI Delivers Public Value

GIEI projects add public value to communities. For example, MGs in Frederick County worked closely with homeless families and public housing residents to build raised beds and teach gardening skills, and MGs in several counties partner with SNAP-Ed educators to teach food gardening to students attending Title I schools that provide free and reduced meals.

Here are just a few of the many notable GIEI projects:

a woman and a girl planting a container garden
In addition to donating produce to the Manna Food Center, UME MGs in Montgomery County started the Cuidando Jardineros Program (“Growing Gardeners”). They gave 244 families (majority English as a second language) a 5-gallon bucket garden in 2015. A 6-month follow-up survey showed success in growing and using fresh produce.
boys harvesting carrots from a container garden
Youth in the Summer Youth Enrichment Program (SYEP) learn about growing and using herbs in the UME, Prince George’s Co. MG Demonstration Garden in Clinton, MD.
A luffa “highline” was featured in the MG Learning Garden at the Maryland State Fair last summer.
Master Gardeners ready to engage visitors to the Learning Garden at State Fair!
two people working on a trellis in a garden
Sandee Heredia and Derex Thompson, both UME, Charles Co. MGs, refreshing a bed in the  “Seeds of Hope” Community Learning Garden at the Southern MD Food Bank in Waldorf, MD. MGs help manage the garden and used it as a teaching/demonstration site.
a person holding a container of produce from a garden
Tori Chrichlow, UME, Charles Co. MG with produce from the food bank garden that feeds people in need.

What’s next for GIEI?

  • Move toward greater Diversity, Equity, Inclusion, and Respect (DEIR) by working with community partners and other UME programs to learn and meet the food gardening needs of under-served residents
  • Teach and demonstrate climate-resilient practices like Improving/protecting soil, growing heat-tolerant crops and cultivars, season extension, cutting greenhouse gas emissions and food waste, and supporting/promoting local agriculture
sign reading how to harvest banana peppers
Signage in Harwood Community Garden, Baltimore City

Enjoy your harvest this year!

By Jon Traunfeld, Extension Specialist, University of Maryland Extension, Home & Garden Information Center. Read more posts by Jon.

Q&A: Pros and Cons of the No-Mow May Movement

Q: Do you have any information related to the “no mow” movement? We have a very weedy lawn and are considering replacing it with Dutch clover. Is that a good idea? Bad idea? 

A: We do not recommend replacing lawn outright with clover. Clover goes dormant in winter, losing leaves, which leaves the soil surface exposed to weed seed colonization and potential erosion. The clovers used in lawns are also non-native and would not support the majority of our native bees (which are specialists, relying on certain native species for pollen, nectar, or plant oils). Generalist bees can use clover or other blooms but these tend not to be the local bees needing the most support from garden plantings.

If you prefer to augment your existing lawn with clover, consider microclover, which is a dwarf and less-aggressive variety of white clover that cohabitates with turfgrass more cooperatively. While not solving any of the other above issues, at least this is a more suitable choice when using clover in a lawn. Our Lawns and Microclover page provides some pros and cons plus links to a more detailed publication (PDF document) about how to go about creating and maintaining this mix.

a flowery lawn with unmowed grasses
Chanticleer’s flowery lawn interpretation, more of a no-mow-ever than a no-mow May situation, and thus of more benefit to wildlife. Photo: M. Talabac

Opinions among professional horticulturists about “No Mow May” actions are mixed because there are both benefits and drawbacks that it creates. You will probably find both proponents and opponents to this practice in Extension and other science-based web publications and articles. The main benefit of the movement is its ability to get gardeners thinking about their landscaping choices and actions and the impacts of these on the ecosystem. (And that’s a good thing!) That said, most of the flowering lawn weeds that no-mow is supposed to protect are non-native and do not support many of our native bees, and allowing them to set seed only enables them to spread further in places where native plants should ideally be growing instead. 

For gardeners interested in having turf serve double-duty as a “bee lawn” – that is, intentionally planted with seed mixtures containing low-growing flowering plants – the benefits and shortcomings of this approach are similar to those with clover lawn conversions or from reducing mowing for limited periods of time. University of Minnesota research shows that bee lawns do provide benefits for pollinators, including native ones. However, most commercially-available bee lawn mixes contain plants from Europe and/or Asia, and are perhaps not the best nutritionally for Maryland’s specialist bee adults or a resource they will be able to use for their young. Some Maryland native plants that can be incorporated into bee lawns, such as Self-Heal (Prunella vulgaris subspecies lanceolata), are not readily available in seed mixes here, and research on Maryland-native plants for use in bee lawns is not available at this time. Visit UMN’s “Planting and Maintaining a Bee Lawn” web page for more detail.

Our energies and efforts aimed at benefiting insects, birds, and other organisms may be better spent creating native plant gardens alongside of (or in place of) lawns, which will not only serve specialist bees more suitably but also will support a variety of other native wildlife in the process. In any garden setting, including when plant selections are native-focused, using a diversity of plant species has several benefits: it can support a greater diversity of wildlife (including pollinators and beneficial insects that help suppress pests), it adds aesthetic and seasonal interest, and it increases the resiliency of the planting as a whole, because different species won’t have the same degree of vulnerability to any one issue (like drought or flooding) that may arise.

white flowers of fleabane in bloom
 Native common fleabane (Erigeron philadelphicus) blooms in a front yard where a portion of the turfgrass was removed and replaced with little bluestem, switchgrass, and a mixture of flowering perennials. Fleabane supports a variety of native bees, solitary wasps, and other beneficial insects. Photo: C. Carignan

Not mowing lawns regularly also stresses the turf by creating a situation where, when mowing does resume, it’s removing much more of the turf’s leaf mass at one time, causing stress and interfering with its normal growth habit that creates a dense lawn. The “grazing response” that mowing triggers, promoting more low growth that fills-in gaps, won’t be happening to the same extent if the grass goes for weeks without being cut, especially as it diverts some energy for growth into producing pollen and seed. (This turfgrass flowering also might be a consideration for people with bad grass pollen allergies.)

This topic of bee resources in lawns as addressed by the no-mow movement is touched upon by wildlife biologist Sam Droege in the native bee special episode of the University of Maryland Extension Garden Thyme Podcast from last summer.

Lawn alternatives, even if not purely native species, are another option when dealing with a lawn that is struggling. While a healthy lawn is providing more environmental services (carbon sequestration, erosion control, nutrient filtering, etc.) than a struggling lawn, if you do not wish to devote resources to improving its health and vigor, then converting those areas to non-lawn is more practical, even if a bit more expensive at first than just rehabbing the lawn. If a tolerance to regular foot traffic from people or pets is needed, then lawn is the best groundcover for this use and you might want to work to improve its health, but otherwise areas not being stepped-on can be planted with other species.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.

Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask Extension. Our horticulturists are available to answer your questions online, year-roundYou can also connect with your local County/City Extension Office and Master Gardener local programs.

Azaleas and Home Gardens

Spring is incomplete without the bold and soft hues of azaleas in your home garden. These spectacular plants are prevalent and have dominated yards and countless gardens in North America. These plants originated in Asia and made their way to the US via Europe around two hundred years ago. Since then, according to the American Azalea Society (ARS), over 10,000 different cultivars, or cultivated varieties, have been registered or named. The high demand for cultivated azalea can be attributed to its small manageable dwarf sizes, diverse attractive colors, deep green leaves year-round, and adaptability to the climate, making them easy to grow.

However, there are equally beautiful native azaleas in North America that are seldom seen in home gardens and are still not as well-known as their Asian cousins. To find them, it would be best to wander from the landscaped yards into the woods. In this post, I talk about the extraordinary beauty and ecology of native azaleas, as they require more attention and care from the gardening community.

What are native azaleas?

Azaleas are members of the heaths (Ericaceae) plant family, which includes cranberry, blueberry, and huckleberries. Because there is often confusion among people between azaleas and rhododendrons, it is much easier to remember that all azaleas are rhododendrons, but that all rhododendrons are not azaleas. In fact, azaleas belong to the genus Rhododendron. Azaleas native to North America are usually medium-sized or tall shrubs with soft, deciduous leaves, funnel-shaped flower lobes, and long tubular flowers with stamens extending beyond their showy petals. There are eighteen North American native azaleas (visit the American Azalea Society and American Rhododendron Society to learn more).

Why grow native azaleas?

Native azaleas display shades of white, orange, pink, red, and yellow throughout the spring and summer. Although most people associate azaleas with spring, several native ones bloom in mid and late summer. It is often noticed that azaleas in their natural habitat show some staggering in their flowering timing, and their flowering durations usually range between 15 to 20 days. So, if you carefully select species based on their flowering timing, you can have azaleas bloom in your home gardens for at least four to five months. Unlike the evergreen cultivated ones, native azaleas have exceptional fall color before they shed their leaves for winter. Most native Azaleas can reach heights of 4’-8’ and can be used in hedgerows and as the background to other flowering dwarf shrubs. Some of the common native azaleas in the woodlands of Maryland, Virginia, and DC are smooth azalea (Rhododendron arborescens), swamp azalea (Rhododendron viscosum), pinxter azalea (Rhododendron periclymenoides), coast azalea (Rhododendron atlanticum) and early azalea (Rhododendron prinophyllum).  

Besides the colorful hues in your green space, growing azaleas will also help maintain the native pollinator network in your local environment. Native azaleas can sustain a variety of fauna through their flowers; they are attractive to bees, butterflies, moths, and hummingbirds. The quantity and quality of nectar and pollen among these plants are often observed to be higher than in the cultivated ones. In general, they have a high amount of concentrated nectar and string-like pollen threads that help attract myriad forms of floral visitors native to North America.

Some azalea species have attractive warm orange and red flowers, and birds can detect warm colors easily. At the same time, insects, including bumblebees and smaller bees (e.g., Andrena sp.), are attracted to light pink, purple, and white palettes. Certain native species, such as sweet azalea and piedmont azalea, have a strong sweet fragrance. Besides providing a sweet smell, their fragrance also helps attract night pollinators such as moths. Nectar volume among the azalea flowers is relatively low compared to its nectar concentration; therefore, the migratory ruby-throated hummingbird makes occasional visits, as birds usually prefer flowers with high voluminous nectar. Their unique floral characteristics also attract diverse butterflies, recognized as potential pollinators for these species. Commonly observed butterflies are eastern tiger swallowtails (Papilio glaucus), silver spotted skippers (Epargyreus clarus), and great spangled fritillaries (Speyeria cybele). The flapping of butterfly wings helps transfer pollen from the male to the female organ and facilitates successful reproduction in these plants. Therefore, growing different shades of native azaleas in your yards and home gardens will be a good idea to support native pollinators.

Native azaleas are also relatively free of pests and diseases compared to cultivars, making them low-maintenance plants. They do not require regular pruning and are moderately slow growers. However, knowing the ecology of these species may be helpful for plant growers. For example, in the forest, these plants are mostly found as an understory of other tall hardwood trees like oaks and chestnuts; therefore, they will do well in less light and shaded areas in the home gardens. Most of them require moisture with good drainage and humus-rich acidic soil. You can learn more about the detailed requirements of the conditions preferred by these plants at the American Azalea Society.

It is never too late to add these cool plants to your home garden.

By Shweta Basnett, Fulbright Postdoctoral Fellow, Department of Entomology, University of Maryland. Visit her website for more information about her current research.


Beyond Broccoli Part Four: Down to the Roots

In this edition of Beyond Broccoli (see parts one, two and three for background) we’re going to start exploring some specific species and subspecies (varieties, groups, etc.) within the genus Brassica. Rather than address each species systematically, I’ve decided on an approach based on the plant parts we usually consume. Never fear, I will inform you when introducing each plant how they fit into the genus.

So let’s start at the bottom, with root vegetables.

Fuku Komachi turnips
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