Weeding in the Woods: Join in our Garlic Mustard Removal Project

Volunteers have been working for the last few years to remove Garlic Mustard plants from Acton's conservation areas. For a few weeks each spring, before it goes to seed, we pick dozens of bags of this invasive plant, in a project to remove this invasive plant from our wild areas.  Volunteers can sign up at actoninvasives.org

What's the big deal with invasive plants?

Invasive plant species start life like any other plant, in a web of other plants and animals, kept in check by predators and parasites of various sorts that evolved to use the plant. A plant species only becomes invasive when:

• it is carried across ecosystem boundaries by human action, and

The Boston Metrowest region is a hotbed for invasive plants. Invasive plants are usually brought in for agriculture or gardening, and we've been doing that for more than three centuries here. In the last century and a half we've had a return of forest and meadow in a lot of former new England agriculture land. Some of the plants that used to be well-contained at first have spread in to the new forests. 

Some of these are hard to miss: Oriental Bittersweet, for example, is that vine that's been strangling many of our trees. As another example, Purple Loosestrife has taken over many wet areas – it's especially visible in the soggy areas near large roads. And our most common wild rose is now Multiflora Rosa, brought in as a 'living fence' for farm animals, but abandoned for that use when it just kept taking over more and more land. The Massachusetts Department of Agriculture, recognizing the seriousness of the problem, now maintains a list of more than a hundred plant species that are illegal to import or sell in Massachusetts, including these and many more. And the Acton Conservation Commission has joinedthe SuAsCo Cooperative Invasives Species Management Area.

Why is Garlic Mustard a target for volunteers?

When Acton's Land Stewardship Committee brought in Chris Mattrick of the New England Wildflower Society in 2004 to teach us about invasive plants, we learned that the right invasive species to go after have these two characteristics:

1. They are causing large and continuing damage

After surveying the invasions in Acton's conservation lands, we decided to focus on one plant species first: Garlic Mustard (Alliaria petiolata). Here's a link to a great flyer about garlic mustard.

Garlic Mustard causes real harm. First, it grows in so thick in the early spring that it shades out any spring wildflowers that may be coming up underneath it. The plant is on a two year cycle, staying alive through the winter so it can prepare to shoot up as soon as it is warm enough. Second, chemicals given off by the roots damage the mycorrhizal fungi needed for most tree growth, so it weakens many nearby trees.

Garlic mustard can be dealt with by volunteers with no special training or equipment. When it puts all its energy into bolting upwards and then growing seeds in the spring, its roots lose strength. It can easily be pulled, roots and all, with a careful tug. A volunteer can fill a large garbage bag with plants in an hour, and we can clear all the targeted infested areas on town conservation lands with three hundred hours of labor each Spring during picking season. That's well more than one person can do during the picking season, but with a pool of volunteers each working a few hours, we can get it done. Three to five years of consistent picking, followed by annual monitoring, will remove all the garlic mustard from an infested area, letting a mix of other plant species grow in instead. 

Why not just let it be?

Some people ask me, why go after these plants? Nature will provide: we could just wait until evolution catches up. Eventually, probably, enough local insects and other plants and animals will figure out how to use garlic mustard as a food source that it will become a proportional part of our wild areas and will stop threatening biodiversity. But here's how I see it: A plant is invasive because we humans have carried it here and let it escape out of context. Cleaning it up is part of the larger task of undoing some of the damage we humans have created on the way. At some point, if we are to continue to thrive as a species on this great planet, we need to turn some attention to building a healthier connection with the life around us by understanding the harm we have done, and figuring out how to repair it.

Come join in

I've found great peace just sitting on a forest floor, patiently picking out garlic mustard plants one by one, and enjoying a fine spring day outside. Come join us if this work calls you – you can learn more or signup for April, May and June pulling sessions at actoninvasives.org.