For most of us, a green leaf in the last weeks of winter brings out a smile. Unfortunately, there’s a wolf in green clothing, and it’s often the first shrub to leaf out in the shade of backyards, street edges, town parks, and forests. The aggressive, invasive, thorny Japanese barberry (JB for short, or Berberis thunbergii, if you want to be precise) is an escapee from backyard horticulture. Three Connecticut researchers determined a few years ago that where JB flourishes, tick populations flourish, too. (See http://bit.ly/barberry-ticks.)

If JB is spoiling your home or community landscape, here’s the good news: It is very visible during March and early April. According to David Gumbart, director of land management for The Nature Conservancy in Connecticut, cutting it after the first flush of leaves is more effective than cutting it later in the growing season.

Gumbart has battled just about every invasive weed that plagues our area. He oversees The Nature Conservancy’s 62 preserves in the state, including seven in our southeastern towns.

“I don’t know exactly how many times you have to cut Japanese barberry before the plant dies,” says Gumbart. “But every time we go back after cutting, we see smaller, weaker shrubs.” He says the mortality rate depends on local conditions and the maturity of the plant.

Why does repeated cutting work? Plants exhaust their food stores after they put out the first flush of spring leaves. If you cut JB or other invasives to the ground as soon as they leaf out, the plants have little resilience against the assault of well-sharpened loppers.

Take the Long View

Gumbart points to the Conservancy’s work at Walden Preserve in Salem, where they have used a mix of herbicides and cutting over the past several years against a host of invasive weeds. Even using the two techniques in combination, it has taken several attempts to weaken and eliminate unwanted plants.

Why not simply uproot JB and other invasive weeds?

First, live roots are usually left behind, and they sprout new top growth. Secondly, root-pulling disturbs the soil. The disturbance brings buried seeds into the upper layers of topsoil, where they are more likely to grow new plants. Repeated cutting, on the other hand, leaves soil undisturbed.

While cutting may not be as satisfying as pulling the plant by the roots, it may bring greater long-term success.

“Think about weed management with a long view,” says Gumbart. “Put it in the context of a three-year plan. If you’ve got a large area to manage, it’s okay to cut just a little bit at a time,” he says. “It takes away some of the feeling that the task is just too daunting.”

“Above all,” he says, “don’t take the weekend warrior approach. It’s the incremental actions that count.”

Gumbart points out the importance of involving neighbors when trying to eradicate invasive plants like JB. Weed seeds and roots don’t respect property boundaries.

Call the Neighbors

He suggests, “Tell your neighbors what you’re doing. It may inspire them to do the same. Imagine how, if everyone simply took care of the invasive plants on their quarter-acre, the overall number of invasive weeds would go down.”

When weed populations decrease, fewer weed seeds enter the bellies of birds and small mammals, or spread into waterways.

JB is not the only invasive weed that goes green early in the spring. Multiflora rose (Rosa multiflora), Japanese honeysuckle (Lonicera japonica), and others green-up early.

To learn more about invasive weeds and how to control them, visit these websites:

• Connecticut’s invasive plant working group at http://cipwg.uconn.edu

• Visit IPANE, the Invasive Plant Atlas of New England: www.eddmaps.org/ipane

• Or visit www.invasive.org.

Want a list of good native plants to replace invasives? Try a filtered database search:

• For shrubs and trees, I visit http://plants.UConn.edu and use the “search by trait” option. Then, I use the filter for CT natives—in addition to specifying the soil and light conditions (and other requirements as well)

• For native flowering perennials and herbaceous plants, try out the University of Rhode Island’s database: http://web.uri.edu/rinativeplants.

Above all, don’t be fooled by early greenery—removal only gets more difficult as the year progresses. Do yourself and your neighborhood a favor. Cut it now.

Kathy Connolly is a landscape designer, writer, and speaker from Old Saybrook. Contact her through her website:www.speakingoflandscapes.com.