Invasive Species Are Crowding Native Plants, Habitat

By Kendra Bobowick

Beware of the Japanese barberry.

Among the invasive plants shocking native flora, this plant, now in bloom, is “particularly troublesome,” said Conservation Commission member Pat Barkman. A prickly plant with a series of small green eaves running the length of its branches harbors the white-footed mouse, which is associated with its role in spreading Lyme and other diseases to ticks. Tick-Borne Disease Action Committee member Mary Gaudet-Wilson also noted the plant’s connection to the mouse.

The barberry, which is a spiny shrub between two and eight feet high, will “take over the forest,” Ms Barkman said. “Pull it by the roots,” she advised, otherwise, it returns. Residents who spot it in the backyard may be inclined to cut it down.

“It will grow back,” she warned. “It seems to like to be cut.” Weed whack, then spray it with weed killer containing glyphosate, she advised.

The plant is in many backyards and “will do just fine,” in an understory or along roads, Ms Barkman said. For several years Ms Barkman has promoted the different segments of Al’s Trail, which is also home to the Japanese barberry. The section near the Pond Brook boat launch off of Hanover Road is bursting with the barberry.

“It’s all over the understory there,” she said.

Flowering takes place this month and into May with a show of pale yellow flowers that hang in small clusters. Bright red berries also grow close to the stalk. Leaves are green, bluish green, or reddish purple. Barberry grows in dense stands under canopy forests, open woodlands, wetlands, pastures, and meadows. According to the Plant Conservation Alliance fact sheet, the barberry “alters biological activity in the soil … displaces native plants and reduces wildlife habitat to forage.”

Japanese barberry was introduced to the United States and New England as an ornamental plant in 1875 in the form of seeds sent from Russia to the Arnold Arboretum in Boston. In 1896, barberry shrubs grown from these seeds were planted at the New York Botanic Garden. Japanese barberry was later promoted as a substitute for common barberry.

The plant conservation alliance fact sheet also warns, “Do not plant Japanese barberry. Because it is a prolific seed-producer with a high germination rate, prevention of seed production should be a management priority. Because barberry can resprout from root fragments remaining in soil, thorough removal of root portions is important.

Ms Barkman suspects that snowplows help sow the plant along roadsides, she said.

Manual control works well but may need to be combined with chemical in large or persistent infestations.

See www.nps.gov and search the National Park Service site to read more about invasive species.

An orientation meeting on May 13 with Deputy Director of Land Use Rob Sibley for the invasive plant removal volunteer group will be at the Newtown Municipal Center Land Use office at 3:30 pm. Anyone interested in attending and/or volunteering can call 203-270-4276.