Green Up Day and... garlic mustard?

Every year, the Conservation Commission sponsors Thetford’s Green Up Day, a statewide volunteer-led effort to clean up trash along our roads. So far this year, volunteers have signed up to cover over eighty different sections of road in Thetford, which is record-breaking.

Garlic mustard, a common roadside invasive plant, has been pulled and bagged in the past as part of Thetford’s Green Up Day effort, but volunteers are no longer able to dispose of garlic mustard in the Green Up Day dumpster. The Conservation Commission is looking for alternatives; you can’t compost garlic mustard because it is not known how long it takes for the toxin it contains to biodegrade, and the transfer station is not willing to store it in bags — compressed under pallets — until it breaks down and can be buried.

Garlic mustard is a non-native weed that poses a serious threat to Vermont’s ecology. It secretes a toxic substance from its roots that kills the soil fungi needed by native plants for their survival. In that way, large areas can become garlic mustard monocultures in a short time. It is particularly a threat to native wildflowers because it can grow in shade. It also disrupts forest regeneration because its toxin kills the forest mycorrhizae that are critical for growth of tree seedlings.

A comprehensive roadside mowing schedule could give a big boost to efforts to control invasive plants — not only garlic mustard but also wild chervil and poison parsnip that have spread like wildfire along Vermont’s roadsides. But it’s complicated. To be effective, mowing has to cut the plants as they prepare to flower, and some invasive species flower and seed earlier than others. If cut too soon, they all can grow new flowering stems. An effective schedule could mean mowing every road in Thetford three or four times a year, yet most years the Town struggles to mow each road once. Developing the schedule would be a challenge in itself, not to mention expensive.

The Conservation Commission and volunteers have made progress on removing garlic mustard in some areas, and they do not want to lose momentum. However, because there is currently no accepted disposal method provided to residents, the Commission has decided — for now – not to advertise garlic mustard removal as part of Thetford’s Green Up Day.

There is still trash to pick up. There are roads that no one has signed up for, including Barker Road, Gove Hill Road, and sections of Route 113 and Route 5, among others. You can see the full list here, and sign up to help.

Green Up Day bags are, well, green, and can be picked up from Latham Library, Town Hall, and the Transfer Station. The bags will be collected outside of the Town Garage (across from Town Hall) on May 1^st between 9 a.m. and 1 p.m.

Drive carefully – people are out on the side of the road picking up litter and (hopefully) pulling garlic mustard, if they’ve found a way to dispose of the weed themselves.