Beware the first leaves of spring

Invasive weeds are among the first plants to leaf out in early spring

Think of them as bait-and-switch artists. They're among the first to leaf out in the shade of backyards, street edges, town parks, and forests.

But take a closer look.

The aggressive, invasive, thorny Japanese barberry (JB for short, or Berberis thunbergii) is an escapee from backyard horticulture. Three Connecticut researchers determined a few years ago that where JB flourishes, tick populations flourish, too. (See report on ticks and barberry.) As if that weren't enough, thorny, twining multiflora rose stems take on an electric green hue this time of year. Invasive Japanese honeysuckle begins its smothering climb over the spring landscape. (Photo: The first leaves of Japanese barberry in March.) 

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

“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.

To learn more about this seasonal advantage, visit "Beware the First Leaves of Spring" at (Or download the PDF below.)

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

• Connecticut’s invasive plant working group at

• IPANE, the Invasive Plant Atlas of New England:


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

• For shrubs and trees, I visit the UConn plant database 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 native plant database.