THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Saturday, July 29, 1995 TAG: 9507290313
SECTION: LOCAL PAGE: B5 EDITION: FINAL
SOURCE: ASSOCIATED PRESS
DATELINE: STATE COLLEGE, PA. LENGTH: Medium: 56 lines
From Pennsylvania to Virginia, spine-covered Japanese vines are suffocating samplings, crawling up walls and destroying gardens at a dizzying rate.
Polygonum perfoliatum, also known as tearthumb or the mile-a-minute weed, was accidentally introduced into Pennsylvania in the 1930s. It is being compared to kudzu, the tenacious green vine that has overrun much of the South.
Both were brought to the United States in the 1930s, but kudzu has done far more damage because it can grow up to 100 feet instead of 25 in a season and doesn't give up conquered territory during the winter. Tearthumb is an annual vine, dying in the winter.
Although the weed can't overrun an entire forest as kudzu can, tearthumb can pose significant problems in young forests with small, fragile trees and seedlings.
The weed has cost timber and pulp companies thousands of dollars by overrunning areas that were replanted after being clear cut, said Will Mountain, botanist with the Pennsylvania Department of Agriculture.
``If the tearthumb seeds are in an area when they clear the timber out, it germinates very prolifically and covers the whole ground,'' he said. ``It covers the pine seedlings, and they will be smothered out. ''
But unlike the deep-rooted kudzu, tearthumb vines can be killed easily by hand or with herbicides.
Mountain was a speaker at a two-day conference in York this month as scientists, state officials and foresters discussed the best ways to control tearthumb.
The vine is thin with triangular leaves, small spines and a saucer-like sheath around the nodes. In late summer, powdery blue, berry-like fruit appear on the weed.
Tearthumb was brought to Pennsylvania by a York nursery importing plants from Japan. It spread to at least 18 Pennsylvania counties and has been found in Delaware, Maryland, New Jersey, New York, Ohio, Virginia, West Virginia and Washington, D.C.
Scott Kurtzman, area forester with The Glatfelter Pulp Wood Co. in Spring Grove, said his company had its first encounter with the weed about seven years ago in York County. This spring, the company had to spray an additional herbicide on a 100-acre tract to control the mile-a-minute weed at a cost of $6,500. Mile-a-minute weed has also caused problems in prairies, city parks in Washington and forests that recently had fires.
Penn State weed scientist Nathan Hartwig said the school is researching less expensive ways to control the weed. The key is killing the vine before June, when it begins spreading seeds. by CNB