Japanese Barberry: Substitute Warriors
by Mary Jasch
Counties and states in the Northeast are stepping up the war on Japanese barberry and other invasive species that assail our forests and other Eastern habitats. Barberry’s “15 minutes” will be cut short in four years.
Its treachery is plentiful: changing forest soil chemistry that promotes weedy growth, reduces biodiversity and regeneration of native species, reduces habitat and supports Lyme Disease.
The Battle of Long Island:
Given the assault on eastern forests by invasive plants, several states and organizations are taking action to curb their use. Japanese barberry may perhaps be the most ruthless and pervasive invasive but its death sentence is nigh. But what will take its sanctimonious place? Read on.
In 2007, New York’s Nassau and Suffolk Counties passed legislation that prohibits the sale, transport, distribution and propagation of dozens of invasive species, including Japanese barberry, Berberis thunbergii. In January 2009, the ban began for 45 species; 32 more will face prohibition between 2011 and 2016. Japanese barberry will be outlawed on January 1, 2014.
The Long Island counties follow Massachusetts and New Hampshire in targeting barberry. Connecticut, Maryland and New Jersey are close behind, developing invasive management strategies.
Because many of these invasives have been important to the horticulture industry, Alexis Alvey, nursery and landscape specialist of Cornell Cooperative Extension of Suffolk County, and seven others: landscape architects and designers, nurserymen, growers and arboretum people including Vincent Simeone, director, Planting Fields Arboretum State Historic Park, began to think about alternatives to the banned plants.
They formed a task force, the Plant Selection Committee for Alternatives to Invasive Plants, and devised a list of substitutes for 77 plants on the counties’ Do Not Sell Lists.
“We try to be as reasonable as we can but there are specific things that we know are invasive in many areas,” says Simeone. “Barberry is a problem in many areas. We’ve seen it in garden situations most often and in woodland areas. It’s pretty much everywhere – even along the beaches of Jones Beach. It’s becoming problematic.”
The Do Not Sell List extensions allow nurseries on Long Island to clear out their invasive stock “because if they already have barberry in production, for instance, they would lose all the money they have invested already,” says Alvey. After January 1, 2014, a nursery with barberry in stock will be fined. Some have already burned their barberry.
The purchase and growing of barberry is based on designers and landscape architects specking them out in large quantities, Simeone says. They are now asking for barberry alternatives with similar texture, color and size to use on big job sites. The committee cites alternatives that are not only non-invasive, but are similar so designers will have choices.
Brid Craddock, certified landscape designer, Association of Professional Landscape Designers, speaks for Connecticut. Craddock and her husband grow many of the plants she uses in her business: native first, then non-native, non-invasive or hyper-aggressive – and no barberry.
“Barberry is so attractive because it’s deer resistant, sun and shade tolerant, and cheap. It’s a tough one to replace apples to apples,” she says. Barberry is often used in foundations plantings because “people want plants that will stay small or can be clipped and look under control for many years.”
Barberry is getting harder to find and nurseries don’t prominently display it anymore, she says. Nurseries stock it but you must ask for it. These days, landscapers use it only when they replace plants, usually in commercial landscapes at gas stations, big box stores, groceries – “around the parking lots because you can’t kill the stuff. You can dump snow on it, salt it, and it’s not going to die. When you’re warranting those plants as a landscaper, you want things that are really tough. You don’t want to spend the money to go back and replace the plants. That’s another reason it is a hard plant to replace.”
Says Ken Druse, renowned plantsman, garden author: “There is nothing quite like barberry – especially from a grower's and landscaper's standpoint. If one were to substitute a plant for barberry, the home owner or landscaper or retailer would have to do it for conscientiousness. If caring for the environment meant enough to enough people, then the ‘substitute’ should be a native, indigenous or local plant – one that has some of the characteristics of barberry – fruit for example, useful food for animals that co-evolved with the plant.”
Native plants are not always the recommended alternatives, although that is usually the first line of thought, says Alvey. “Non-native, non-invasive plants are the second line of defense. Perhaps in the future when people start focusing more on native plants, better cultivars of native plants will come out and they’ll be more available. For the meantime, we’ll not limiting alternatives just to native plants.”
All agree that alternatives exist for different forms of barberry but they understand the industry’s challenges. Mark Brand, professor of ornamental horticulture, University of Connecticut in Plant Science and Landscape Architecture Department, is involved in several studies on barberry: “I would say it shouldn’t be used but on the other hand there are a lot of people who are having difficulties due to heavy deer pressure, or they’re just working difficult landscape sites. Increasingly more native plants are being developed and selected for, so that’s helping too.”
The bottom line, though, is barberry’s effects on soil chemistry, forest composition, native plants, diversity, and increased incidence of Lyme disease that cannot be ignored.
Says Simeone: “There is this big push, this big movement in horticulture, whether you’re talking about the mid-west, the far west or the northeast or the southeast, we’re looking for alternatives to these invasives that are becoming a problem. Barberry is just the tip of the iceberg.
“You’re going to see coming down the pike lists of alternatives for landscapers or professionals or growers so they can at least let landscapers do their trade and not have to worry about the invasiveness of plants. People have to make a living and they have to perform their craft and they have to have their tools at their fingertips. We’re trying to give them alternatives so they spec out certain things and have different things at their discretion.”
Plant Selection Committee for Alternatives to Invasive Plants Alternatives:
Standard Purple Barberry like atropurpurea ‘Rosy Glow’:
Smoke bush, Cotinus coggygria
Purple cultivars of old-fashioned weigela: Wine and Roses, Fine Wine, Dark Horse, Midnight Wine
Eastern ninebark: Physocarpus opulifolius 'Summer Wine' and 'Diablo'. Very hardy, purple foliage, substantial in size. Use as cut back shrubs. Cut back Diablo to one foot in March so it shoots up three to four feet every season with good purple foliage. This height is a good alternative for purple barberry. You would not be encouraging flowers but you can’t have everything.
Dwarf Purple Barberry like Red Pygmy:
Dwarf purple weigela: Wine and Roses, Midnight Wine, Dark Horse, Fine Wine, many varieties with same mounding effect. Different flowers, but you’re not growing barberry for their flowers anyway. You grow them for foliage and form. Non-invasive, hardy, gives the same look.
Yellow foliage Glossy Abelia: Francis Mason, Golden Glow, Silver and Gold Anniversary. Hardy to Zone 6, flowers all summer, takes shade, nice foliage. Abelia is emerging an easy, durable shrub that can be used in a variety of ways, says Simeone.
Chamaecyparis pisifera ‘Aurea Nana’
Dwarf forsythia: Gold Tide grown for its foliage, hardy to Zone 4, 5.
Honeysuckle: Baggesen’s Gold Boxleaf. Evergreen, low-growing, mounded, hardy to Zone 7A. Not invasive, easy, sun or shade.
Weigela Gold varieties: Troubadour with intense gold leaf, red flower, good cut back shrub. Cut back every other spring for nice flush of foliage. Grows to four feet.
Eastern ninebark, Physocarpus opulifolius: new varieties, suggests Brand
Standard Green Barberry:
Cranberry cotoneaster: Cotoneaster apiculatus 'Tom Thumb'
Bush cinquefoil: Potentilla fruiticosa
Dwarf fragrant sumac: Rhus aromatica Gro-Low
Old-fashioned weigela: Minuet, Dwarf Red Prince, White Knight. Drought tolerant, grows in infertile soils, compact with similar shape, color and growing requirements.
Thorny Barrier Hedge
William Penn, wintergreen barberry, B. julianae, evergreen to Zone 5 & 6.
Druse suggests the hardy trifoliate orange, Poncirus trifoliate
Juniperus: harmless, evergreen, deer resistant and pretty tolerant of foundation conditions: reflected light of the building and dry conditions in summer months. Many low-growing junipers turn burgundy, silver, grey or blue in winter. Great for situations where the snow plow is dumping snow on things. “You can’t be too much of a plant snob,” she says.
Other choices: leucothoe, clethra, itea
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published January 30, 2010