Category: pollinator gardening

Mustard: It’s Not Just for Hotdogs

On By durhammastergardenersIn adding vegetables to annual flowers, annuals, bees, beneficial insects, container gardening, Durham NC, easy to grow plants, edibles, fall gardening, fall vegetable gardening, garden design, gardening, gardening in pots, Gardening information, gardening NC, growing mustard, landscaping for wildlife, mizuna, mustard plants, pollinator gardening, pollinators, sustainability, Uncategorized, urban garden, urban gardening, vegetable gardening

By Melinda Heigel, NC State Extension Master GardenerSM volunteer of Durham County

(Left) The big, bold leaves of ‘Red Giant‘ mustard take center stage in this large container providing texture, height, volume, and intense color. This mustard was fast growing, survived cold temperatures with minimal protection. It was also slow to bolt when the weather got warm in the spring. (Middle and right) The ‘Miz America’ mizuna-mustard hybrid was equally stunning in a built-in planter box and potted alongside pansies, violas, and a lemon cypress, (Hesperocyparis macrocarpa ‘Goldcrest’ ). While these head turners are edible, I planted them for their color and form. (Image credit: Melinda Heigel)1

Wait? I thought this was a blog about gardening, not cooking! Well, the mustard I am referring to isn’t the zippy condiment we all know but is the plant I discovered is a star in fall containers. I’ve written in the past about the herb bloody dock, also known as sorrel, and what a bullet-proof companion it is for pansies, violas, snapdragons, ornamental kale, cabbage, and other autumn-to-spring plants. Last year I tried adding mustard to my potted arrangements and was thrilled with the results.

A Question of Hardiness

Along with broccoli, collards, and kale, mustard is a cole crop that performs best in consistently cool temperatures when grown in the vegetable garden. But over the last couple of years I’ve started seeing different mustard plants at the local nurseries more and more alongside the annual cold-weather ornamentals. The mustard plants offered some really interesting leafy forms for planting in pots. I was dubious, though, about their hardiness over the winter, unprotected in containers, but what is gardening without experimentation? With the exception of a couple nights with temps in the teens in the dead of winter, I did not cover any mustard plants. To my surprise, they performed just as well as their cool-weather container companions.

(Left to right) Mustard plants already making a debut at the local nursery this month alongside fall’s usual suspects. In late spring of 2024, my ‘Miz America’ mustard plants produced bright yellow flowers when they bolted. The plants really earned their keep–providing interesting leaves for months followed by these showy late-spring blooms. And did I mention spring pollinators were drawn to their nectar and pollen? (Image credit: Melinda Heigel)

If the spring weather warmed up too quickly, as it is known to do in central NC, I also wondered whether these cool-temp lovers would bolt (flower) and fade too quickly given their prominent placements. Most of the containers were in the hottest place around our house–on a dark-colored deck that receives full sun. Happily, the mustard tolerated a good number of hot days in late April and early May before bolting. Even after flowering, they were still going strong when I removed them to make way for summer plants. While I may have just the right conditions in my landscape for these results, I can’t chalk this success up to anything remarkable. Mustard plants are easy to grow. And I’ve come to find out, one of the types I planted is actually bred to be bolt resistant, ensuring longevity.

Mustard Varieties for Annual Container Gardening

Red Giant Mustard (Brassica juncea ‘Red Giant’)

I found this to be a striking specimen. In my big container, it quickly grew to be over 3 feet tall, with gracefully arching leaves that reminded me of a classical acanthus—yes, you really can wax poetic about mustard. If grown in optimum conditions, this plant has been reported to grow as large as 4 feet. Though I have not experienced this, don’t underestimate its vigor. When planning your mixed pot, give it plenty of room. ‘Big Giant’ mustard leaves start off green but mature into a deep maroon with contrasting green stems, midribs, and leaf veins. This plant is specifically bred to be both cold-and-bolt tolerant. Frost intensifies the color. It grows best in full sun with well-drained soil. It paired nicely with the flowering cushion spurge ‘Ascot Rainbow’ (Euphorbia x martinii ‘Ascot Rainbow’) as a backdrop.

In terms of its characteristics as an edible, this mustard has a bold taste like wasabi or horseradish and can be pickled, eaten cooked (mature leaves), and eaten raw (young leaves). Hot weather sharpens the flavor, especially in the older leaves of the plant.

‘Red Giant’
‘Miz America’

Image credit: Melinda Heigel

Miz America Hybrid (Brassica juncea ‘Miz America’)

At once striking and delicate, the deeply lobed and serrated leaves of this mustard are a showy deep burgundy with vibrant hot-pink midribs and venation. Like ‘Red Giant,’ it is a fast grower and prefers full sun. It serves as an excellent filler in containers, given its upright and compact habit.

From a culinary perspective, ‘Miz America’ has a mild peppery flavor. It’s a hybrid plant that comes from crossing two distinct mustard varieties. One of the parents, mizuna, is a mild green mustard, which gives ‘Miz America’ its beautiful serrated edges and mild flavor. You can enjoy the leaves of all mustards in a salad by picking them young—under 6 inches. If picked at a more mature size, they can be added to a dish to impart a hint of sweetness with a mustard tang. Consider adding them to a bowl of hot, creamy soup such as butternut squash or tomato. Not only does it give you additional nutritional value without adding additional calories, but it adds a nice crunch and a bit of zing.

I’ve yet to replant my containers and built-in planter box this fall, but you’d better bet that mustard plants will be making a repeat performance in 2024. I’ve already seen ‘Red Giant’ in the nurseries, but I am also on the hunt for some other intriguing mustards to test out—namely ‘Brazen Brass’ and ‘Dragon Tongue.’ If you want something unusual, showy, and even tasty in your fall plantings, remember to go heavy on the mustard.

Notes

1–Want a closer look at a photo? Simply double click on the image for a better view.

2–According to Missouri Botanical Garden, Brassica juncea, known by its common names Chinese mustard or brown mustard, is listed as a noxious weed in some states including Michigan, Florida, and Alaska and considered invasive. Cultivars discussed here are bred to be used as annual edibles or ornamentals in gardens.

Resources and Additional Information

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Bringing Plants of the Piedmont back to Downtown Durham

On By durhammastergardenersIn bees, beneficial insects, birds, cover crops, CPTED, crime prevention through environmental design, Downtown Durham, NC, drought tolerant plants, Durham NC, garden design, gardening, Gardening calendar, Gardening information, gardening NC, green mulch, ground covers, ground covers for living mulch, how to improve soil, insects, landscaping for wildlife, living mulch, native plant list, native plant list for Piedmont NC, native plants, Natives, NC Native Plants, Perennial, phenology calendar, Piedmont Prairie Garden at Rotary Plaza, pollinator gardening, polyculture, renewable gardening, soil, soil health, sustainability, sustainable garden design, sustainable watering, sustanability, Uncategorized, urban challenges in landscaping, urban garden, urban gardening, urban heat islands, urban planning, urban prairie garden, urban wildlife, uuban service benefits in landscapes, water wise plants, wildlife

By Eric Wiebe, NC State Extension Master GardenerSM volunteer of Durham County

A once neglected site, Rotary Plaza in downtown Durham comes alive in July 2021 with sunflowers that produce seeds for wildlife. Millet, a grain used here in the design and novel to many urban dwellers, also serves as a great food source for gold finches and other birds. (Image credit: Ben Bergmann)

Have you noticed changes to the plantings in downtown Durham over the past few years? If not, you need to head on down, walk around, and appreciate the transformation of the many of the city-owned green spaces. This transformation, and the strategies behind it, point to a new way of thinking about our relationship to the landscape, both in urban settings like downtown, but also in our own yards. 

I had the pleasure of both walking around downtown Durham with and then sitting down and talking to Ben Bergmann, the architect of this transformation. Ben was hired by City of Durham in September 2020 and charged with re-envisioning and elevating horticulture in downtown Durham, including creating a Downtown Horticulture Crew within Landscape Services. Ben brought a widely varied background to this position, trained with BS, MS, and PhD degrees in plant sciences, and working as everything from small business owner and farmer to tropical agroecologist and research scientist. One thing all this work has in common is plants and his great love of them. Ben feels this broad range of experiences has helped prepare him for a job that has him applying both the art and science horticulture to a municipal government position with its many constraints and opportunities and multitude of stakeholders. 

“When I started, I realized I needed a mission statement to clearly and concisely communicate to my supervisors and the public what I and my unit in government is doing.” He stated that his landscape design and management are guided by the goal of enhancing

  • Environmental sustainability
  • Programmatic stability
  • Aesthetic appeal
  • Service benefits

He notes that it is important to recognize that these categories are not mutually exclusive, but each has a role to play in his horticultural work supporting the living landscape in downtown Durham. 

Designing Sustainably

Ben explains that a crucial re-orientation is to start planning a landscape by thinking about how it can best align with the ecosystem, and that means starting with native plants that can be used. “For urban contexts some people would say that there is nothing native to these downtown spaces, and they will use this as an ‘out’ to plant whatever they want. I don’t embrace this–something was native, originally, in these spots. Many times these native plants can and will grow and thrive in these spaces.”

When Ben thinks about which native species to use, he first looks for plants native to the North Carolina Piedmont and secondarily to the larger Piedmont of eastern U.S. He notes, however, that it is very important to select plants with a long-range vision. That is, when accounting for global climate change, plants that are going to be here in 20 years may very well be in an environment that looks more like the southern Piedmont, our coastal plains, or South Carolina.

(Left to right) By selecting plants that can cope with a warming environment, Bergmann installed dwarf palmetto (Sabal minor), a plant typically associated with climates in the native ranges east and south of Durham, NC, and shown in green on the USDA’s zone map. (Image credit: Ben Bergmann; https://plants.usda.gov)

While native species take the lead when planning bed renovations, Ben states that non-native plants can still play a role. Returning to his guiding principles, non-natives can help fill functional gaps that might be hard to resolve in the short run with native species. Similarly, there are times that a spot planting of a non-native will help achieve a particular aesthetic goal by providing highlight color, texture, or architecture.

(Left to right) Before, a non-imaginative flag pole bed at Durham Parks and Recreation building included a highly invasive and exotic species: Nandina domestica. After a re-imagining, the same bed demonstrates there is a place for non-native plants alongside natives, especially during transition phases. (Image credit: Ben Bergmann1

Because the legacy plantings downtown were almost 100% non-native, it means that during a bed’s transition period, some non-natives may be left to help visually and functionally stabilize the bed until new, native plants can get established and then take over. Among other things, the non-native plants retained just for the transition can provide shelter from the sun and wind during establishment.

(Left) The process of establishing an urban prairie at the Rotary Plaza began in September 2020 with beds filled with weeds and remnants of long past garden attempts. (Middle) In March 2020, the the beds are full of cover crops: crimson clover, a nitrogen fixer that is great for pollinators in early spring, and winter rye, which has high biomass production and deeply penetrating roots. The intricate planting pattern reflects intentionality and provides visual interest. (Right) By July 2022 the Piedmont Prairie Garden at Rotary Plaza is realized and chock-full of sustainable native plants. (Image credit: Ben Bergmann)2

Even given how much he has achieved is such a short time, Ben still takes the long view when planning and planting. For example, cover crops have been used in very purposeful ways in areas such as the Rotary Garden. During the initial transition of this space, cover crops were planted and maintained in ways that not only helped build the soil, but created visual interest. Over time, the cover crops matured and eventually replaced with native perennials, creating an evolving horticultural narrative in this space. As Ben said, “Some [landscape] designers shy away from transitions–they want to ‘put a tarp over it’ until it has reached its final phase. I don’t shy away from transitions; they are an important part of my plans.”

Ben notes that using select non-native plants, cover crops, and other annuals allows him to more easily use seeds, plugs, and small plants in the beds. In the case of herbaceous perennials and woody plants, besides being less expensive, younger, smaller plants will typically develop more robust root systems and quickly outgrow their bigger counterparts.

Addressing Urban Challenges

Ben was quick to remind me of the many contextual limitations and challenges the Downtown Horticulture Crew faces daily that home suburban gardeners rarely have to contend with. For example, CPTED (Crime Prevention Through Environmental Design), is an important set of guiding heuristics that often preempts other design considerations. In addition to making sure plantings do not screen illicit activities, it also disallows designs that interfere with security cameras or impair pedestrian safety, including driver site lines at street crossings. 

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The center of the Chapel Hill Street parking lot is a perfect example of an urban heat island with even hotter microclimates where landscapes are needed. (1) In January of 2022, the lot was cleared of weeds and other unhealthy, dated, and non-native landscape plants. (2-5) The view in 2024, after Bergmann and his team revitalized the area with an assortment of heat-tolerant natives. (Image credit: Ben Bergmann)3

Most of the beds Ben and his crew manage are surrounded by heat absorbing asphalt and concrete and buildings with glass that intensify solar radiation by reflecting light onto them. This creates heat islands much hotter than in surrounding communities. In addition, tall buildings funnel wind through these spaces and block rain, further desiccating plants. 

Humans also are unhelpful, by walking on, driving over, or otherwise physically challenging plantings. Some soils are more like landfill or construction sites, and many have the negative impact of overuse by dogs on their walks. Even with these challenges, Ben has identified quite a few native species that are up for environmental extremes while still fulfilling functional and aesthetic goals. Not surprisingly, he is currently exploring the possibility of a demonstration xeriscape-inspired bed. This one may very well include some non-native plants more typically found in desert environments.

Educating the Community

Ben understands that an important part of his job is educating not only the workers and residents of downtown Durham but all city residents and visitors as to a new way of envisioning landscapes. Landscapes that, while they exist in a human-built environment, much more clearly reflect real ecosystems of the NC Piedmont. This means not only planting predominantly native species but planting them in soil nourished by natural mulches created by the plants themselves rather than imported, dyed wood chips. He also allows the plants to go through full cycles, creating visual landscapes that sometimes predominate in browns, grays, and blacks, as much as greens, yellows, and reds. 

(Left to right) The Piedmont Prairie Garden at Rotary Plaza in early January with the last vibrant colors and in late February, when the remaining plants still create an almost black-and-white picture. (Image credit: Ben Bergmann)4 (Below) By designing a phenology calendar for his plantings, Bergmann pays careful attention to nature’s timing. This tool helps gardeners know when to plant, specific bloom times, and when colors, textures, and other elements are present throughout the seasons. For a closer view, click on the link for an electronic version of the calendar in our Resources and Additional Information section below.

He is heartened that there is a growing critical mass of professionals helping him in this educational work. The City of Raleigh and Wake County has been hard at work creating plantings that reflect this same vision. He also has strong allies at Duke Gardens, where Annabel Renwick, has provided both inspiration and plants for some of the bed designs. Ben recognizes that it will take a while both for his beds to reach the final stages of their design vision and for Durham residents to embrace this new look, but he has already received lots of positive feedback for his renovated beds. It will also be up to Durham Master Gardeners, and committed gardeners everywhere, to help continue to educate the public and support this work.

Plant lists for featured Downtown Durham Sites

1–The planting design at the Parks and Recreation administration site include a mix of natives (*) and non-native plants: threadleaf coreopsis* (Coreopsis verticillata), creeping phlox* (Phlox subulata), eastern ninebark* (Physocarpus opulifolius), panicle hydrangea (Hydrangea paniculata), lantana (Lantana camara), coleus (Solenostemon scutellarioides).

2–Plants in the Piedmont Prairie Garden at Rotary Plaza include swamp milkweed (Asclepias incarnata), blue mistflower (Conoclinium coelestinum), purple coneflower (Echinacea purpurea), Joe-Pye weed (Eutrochium fistulosum), Spotted Joe-Pye weed (Eutrochium maculatum), common sunflower (Helianthus annuus), scarlet rosemallow (Hibiscus coccineus), larger blue flag iris (Iris versicolor), cardinal flower (Lobelia cardinalis), switch grass (Panicum virgatum), garden phlox (Phlox paniculata), hoary mountain mint (Pycnanthemum incanum), brown-eyed Susan (Rudbeckia triloba).

3–Center of Chapel Hill Street parking lot showcases the following native plants: sedge (Carex bicknellii), purple love grass (Eragrostis spectabilis), Elliott’s lovegrass (Eragrostis elliottii), scarlet rosemallow (Hibiscus coccineus), swamp rosemallow (Hibiscus moscheutos), Virginia sweetspire (Itea virginica), tulip poplar (Liriodendron tulipifera), black-eyed Susan (Rudbeckia hirta).

4–The Piedmont Prairie Garden at Rotary Plaza in late February still offers color, texture, and winter interest. They include climbing aster (Ampleaster carolinianus), scarlet rosemallow (Hibiscus coccineus), switch grass (Panicum virgatum), hoary mountain mint (Pycnanthemum incanum), white goldenrod (Solidago bicolor), showy goldenrod (Solidago speciosa)–with touches of hopeful green, beardtounge (Penstemon digitalis), eastern beardtounge (Penstemon laevigatus), stoke’s aster (Stokesia laevis), adam’s needle yucca (Yucca filamentosa).

5– See below for Bergmann’s list of natives that are tried-and-true performers for Durham and central North Carolina.

Resources and Additional Information

Piedmont Prairie Garden at Rotary Plaza Bloom Time / Color Calendar (electronic version)

https://go.ncsu.edu/piedmontprairiecalendar

NC State Extension on landscaping for wildlife with native plants in urban environments

https://content.ces.ncsu.edu/landscaping-for-wildlife-with-native-plants

North Carolina Native Plant Society’s list of recommended native species

Recommended Native Species

NC State Extension on all things native plants

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