Thursday, September 23, 2021

Life & Style

How to Win the Weed Wars

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Pennsylania sedge (Carex pensylvanica) appears grass-like, but it is a native sedge. It is very adaptable to dry, shady conditions but will thrive in brighter, wetter conditions as well. Appalachian sedge and white-tinged sedge are also excellent dense ground covers. Photo courtesy of Kathy Connolly

Pennsylania sedge (Carex pensylvanica) appears grass-like, but it is a native sedge. It is very adaptable to dry, shady conditions but will thrive in brighter, wetter conditions as well. Appalachian sedge and white-tinged sedge are also excellent dense ground covers. (Photo courtesy of Kathy Connolly)

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Nancy DuBrule-Clemente retired from Natureworks this year, but remains active as a speaker and writer. And she still works sometimes at Natureworks. She has had a 50-year career in Connecticut horticulture. Photo courtesy of Nancy DuBrule-Clemente

Nancy DuBrule-Clemente retired from Natureworks this year, but remains active as a speaker and writer. And she still works sometimes at Natureworks. She has had a 50-year career in Connecticut horticulture. (Photo courtesy of Nancy DuBrule-Clemente)

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Mugwort is one of the region’s most aggressive weeds and is on the state’s invasive species list. It spreads by powerful underground runners as well as seeds. Photo courtesy of Nancy DuBrule-Clemente

Mugwort is one of the region’s most aggressive weeds and is on the state’s invasive species list. It spreads by powerful underground runners as well as seeds. (Photo courtesy of Nancy DuBrule-Clemente)

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Dense plantings and undisturbed soil are two important ways to minimize the presence of “super-weeds” such as mugwort. Photo courtesy of Nancy DuBrule-Clemente

Dense plantings and undisturbed soil are two important ways to minimize the presence of “super-weeds” such as mugwort. (Photo courtesy of Nancy DuBrule-Clemente)

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Common juniper forms dense mats in difficult conditions. The variety depicted here is Juniperus communis ‘Repanda’, one of the author’s favorites. Photo courtesy of Krzysztof Ziarnek, CC 4.0

Common juniper forms dense mats in difficult conditions. The variety depicted here is Juniperus communis ‘Repanda’, one of the author’s favorites. (Photo courtesy of Krzysztof Ziarnek, CC 4.0)

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Barren strawberry, Geum fragarioides, forms a dense groundcover in the shade or part shade. The yellow flowers appear in May. The plant is native to the northeast. Photo courtesy of Kathy Connolly

Barren strawberry, Geum fragarioides, forms a dense groundcover in the shade or part shade. The yellow flowers appear in May. The plant is native to the northeast. (Photo courtesy of Kathy Connolly)

Nancy DuBrule-Clemente has encountered a few unwanted plants—aka weeds—during her 50-year career in the state’s landscape. Graduating from UConn in the 1970s, DuBrule-Clemente went to work in the landscape profession and stayed.

On Thursday, June 24, she’ll explain some hard-won insights in an online talk, “The Weed Wars: Dealing with Weeds Organically,” and proceeds of the event will go toward a scholarship fund that will benefit a cause near and dear to her heart.

“I am passionate about educating new horticulturists,” she says. “We need more people in the industry.”

Many know DuBrule-Clemente for the destination garden center and landscape company she founded in 1983, Natureworks. She ran the business at its current location on Forest Road (Route 22) in Northford since 1990 and has promoted nature-friendly, organic approaches to ornamental landscapes since the beginning.

As a member of the Connecticut Northeast Organic Farming Association (NOFA), she was on the committee that defined “organic” in the context of landscaping beginning in the late ’90s, similar to how the USDA defines “organic” in the context of agriculture.

Those standards are taught now in NOFA’s Accredited Organic Land Care Professionals program. See nofa.organiclandcare.net to find out more about that.

She is also known for witty, informative talks at the Connecticut Flower and Garden Show, among many other venues.

DuBrule-Clemente sold Natureworks to three employees in January 2021 and partially retired. The new owners are committed to keeping its spirit alive as ever.

Bringing It Home

How does a horticulturist with 50 years of experience manage the unwanted plants in her home landscape?

“My home gardens are not so neat and tidy as people might expect,” she says. “I don’t get too worked up about hensbit or creeping Charlie. Some clover is okay. I don’t worry about having a nice lawn.

“I haven’t used conventional mulch in over 12 years,” she adds.

Mulch, she says, generates a weedy cycle that gets ahead of the gardener quickly.

Her replacement for ornamental mulch?

“I use dense plantings that fill the garden and leave no soil exposed. They act as living mulch,” she says and adds that leaf litter is great mulch, too.

“I use a lot of self-sowing native plants such as asters, goldenrods, and fleabane,” she says. “I let them self-seed and spread by roots, but if they’re getting too aggressive, I edit them by cutting off the flower heads before they go to seed, or I trim them to the ground.”

She notes there are many aggressive natives that people are quick to call weeds. Among them are Virginia creeper, fleabane, and hay-scented fern, plus many others.

“Can a native plant get too aggressive? It’s an important question,” she admits. “A plant can have lots of ecological value but eventually overrun a landscape.”

Some natives are inconvenient to humans, too, such as poison ivy or thorny greenbrier.

Seeking a State of Balance

She adds, “In my home gardens, I’m looking for a state of balance. For me, that means covering the ground and feeding the pollinators.”

Given those guidelines, overgrown native plants are far from her top concern. The non-native super-weeds such as bittersweet, mugwort, and Japanese knotweed are more important. These destructive invaders can ruin vast landscapes in just a few years. Their impact is not only aesthetic, but environmental and economic.

How can the average homeowner manage super-weeds organically?

“We have to educate ourselves,” she says. “For instance, most people don’t know the difference between an annual, a perennial, or a biennial. When you’re targeting a particular invasive plant, that information is important.”

Japanese stiltgrass, for instance, is a warm-season annual grass that germinates in early summer and produces voluminous seeds in late summer. It’s essential to prevent the stiltgrass from going to seed. By cutting the plants short in late August or early September, we can interrupt the seeding cycle. The current year’s plants won’t come back a second year. After several years of this treatment, the soil-embedded seeds will be exhausted, and the problem declines.

On the other hand, mugwort is perennial. It spreads both by roots and seeds. A cutting strategy that works for stiltgrass will only barely dent a mugwort stand.

DuBrule-Clemente notes that in both cases, it’s important to leave soil undisturbed.

“There is almost no place for the rototiller in today’s home landscape,” she says.

No-till methods are the way to go, which she calls “gardening from the top-down.”

“We have to learn to manage land, to manage seeds for the long haul,” she says. “This isn’t your grandfather’s landscape anymore. We need different tools to operate successfully in the modern environment.”

Living Mulch Tips

Some plants form dense ground covers. Their thick roots make it difficult for other plants to invade the space, while the leaves or needles shade out the seedlings of unwanted plants.

When planted into an adequately prepared area, they reduce or eliminate the need for shredded wood mulch. Living mulch is not a new idea; witness the wide use of Japanese pachysandra. Now, designers and gardeners are choosing more native plants for this purpose.

Living mulch exists in diverse forms, from needled evergreens such as common juniper to grass-like sedges and flowering plants. Three examples are shown here.

Site preparation is key to success. Take the time to clear the living mulch area of unwanted plants. For instance, use a 12-inch cover of raw wood chips or a plastic smother for up to a year. This length of time eliminates most existing plants. It may be more time than we like, but it increases the success of the living mulch. After the space is as weed-free as possible, consider one or more of these plants to former this living layer.

“The Weed Wars: Dealing with Weeds Organically” will be Thursday, June 24, 7 to 8:30 p.m. Registration can be done at www.cthort.org. The program will cover how to understand and manage weeds organically. Topics include understanding weed life cycles and growing habits, dealing with the dormant seed bank in your soil, passive bed preparation and smothering, timely deadheading, and planting in layers to reduce weed competition.

All proceeds will benefit the scholarship fund operated by the Connecticut Horticultural Society at cthort.org/section/programs-events/scholarships.

Kathy Connolly is a writer and speaker from Old Saybrook who focuses on natural land care, landscape design, and native plant horticulture. For more information, email Kathy@SpeakingofLandscapes.com.






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