This article first appeared in the June 19, 2014 edition of the Vermont Standard.
By Katy Savage, Standard Staff
BARNARD — Mary Blanton has been battling the weeds in two meadows of North Perry Road in Barnard for the past five years.
She rips the four-foot tall plant with white flowers every summer on her walks. At first glance the plant looks like Queen Anne’s Lace, but it’s actually wild chervil — a weed that spreads rapidly and competes with other crops by taking sunlight and nutrients.
Invasive plants like chervil, wild parsnip and Japanese knotweed have been spreading rapidly in the state and have only gotten worse by mowing. Roadsides are typically mowed in the middle of summer, after the plants have gone to seed.
“It’s become more of a problem. The species are starting to become ever more abundant this time. Roadway mowing can be a way they take ahold of an area and end up spreading outwards,” said Paul Marangelo, a senior conservation ecologist at The Nature Conservancy.
But control is difficult when the plants go to seed at different times.
“You could be out there mowing for parsnip and meanwhile you’re spreading the seeds for other invasive species,” said Craig DiGiammarino, an environmental program manger for the operations division of the Vermont Agency of Transportation.
Due to the extensive mowing schedule the state has and the need to keep propagation down, mowing earlier is “economically not feasible,” DiGiammarino said.
Pomfet has mulled the mowing dilemma for at least the past year. This year, the town has tried to mow before June 15, before the grass is hardly long enough to mow.
“To do everything early and do it before the growing season comes in seems counter-productive,” said Selectboard member Phil Dechert at a past Selectboard meeting.
Pomfret Road Foreman Art Lewin said three contractors laughed when he said he wanted to mow so early. Those who responded to his bid request said they would mow the road twice, once in late summer and once before June 15 for $17-18,000. It would be more costly than last year, when the road was mowed once in August for about $11,000.
The town highway department has also discussed mowing the 67 miles of road itself, but that would put the road crew down one person for potentially six weeks.
Several residents have demanded change.
“It’s not simple,” said Joanna Long, a member of the Pomfret Invasive Plant Committee, which is now trying to identify where the invasives are in Pomfret.
Hartland has recently purchased a new $19,000 mower so the highway department can mow certain areas when it needs to—before the plants go to seed.
“We’ll have control of it,” Town Manager Bob Stacey said.
Woodstock hires a contractor to mow in the middle of growing season. Although Woodstock has Japanese knotweed with large bamboo-like stalks in the east end of town, Town Manager Phil Swanson doesn’t know of any invasive plants along the roadsides in Woodstock.
“You’re throwing away your money” to mow sooner, Swanson said.
VTrans has had Best Management Practice for Roadside Terrestrial Invasive Plants in place since 2012. The state doesn’t try to eradicate the plants, but does try to minimize how they spread. Employees are supposed to wash equipment every time after they mow, but DiGiammarino “cannot verify if it happens or not,” he said.
The Best Management Practices advises road crews to not mow plants like Japanese knotweed, purple looestrife and phragmites.
Controlling the plants is sometimes difficult. Chervil taproots can grow six feet deep. A report from the University of Vermont suggests repeatedly mowing it before it goes to seed or digging it from the roots before it flowers to get rid of it. Wild parsnip can cause skin reactions. The plant can be cut below the root before it seeds or hand-pulled using gloves, while Japanese knotweed can have roots 10 feet below the ground and can re-sprout with only a piece of the plant. The weed can be regularly pulled or the stalks can be repeatedly cut to offset growth rhizomes, according to a report from the University of Maine.
The state has limited mowing activity both for financial reasons and invasive plant reasons. VTrans used to take 3-4 passes on the roadsides, now it only takes one in late June or early July.
“We are managing our activities,” DiGiammarino said.
The invasive plants can also be spread by animals, equipment and people.
Wild chervil has taken over Barnard Selectboard chair Tom Morse’s house in the past 10 years.
“I don’t think I’ve made any progress on it but I don’t think it’s made progress on me either,” he said.
Morse is going to be running the roadside mower with the road crew this summer.
“If it’s convenient I would be happy to change anything,” he said about the town’s mowing practices.