Birds, Bugs, and Garlic Mustard: Why Concord Is Pulling Weeds

A spring tradition with muddy boots included

Removing Garlic Mustard to help birds, bugs, and native forests thrive.

By Peter Alden For the past five years, I have helped the Concord Department of Natural Resources map infestations of Garlic Mustard along all 100 miles of roads in Concord. Invasive plants are becoming one of the greatest ecological threats in New England, and I have watched their spread accelerate dramatically over my lifetime.

These mostly Eurasian plants were completely unknown to Henry David Thoreau in the 1800s, yet today dozens of invasive species are overwhelming native vegetation across our forests, wetlands, and roadsides. Because they lack the insects and diseases that kept them in check in their native countries, they spread rapidly and often form dense monocultures that crowd out native wildflowers, shrubs, and tree seedlings.

One of the worst offenders is Garlic Mustard, a rapidly spreading European weed that now dominates many roadsides and woodland edges throughout Massachusetts. Although it can be used as an ingredient in pesto, it produces enormous quantities of seeds that quickly create solid patches, displacing native plants that wildlife depends upon. It is easy to recognize in spring by its toothed leaves, multiple stems, and small white flowers blooming in May. Winter snow plows often help spread the seeds of Garlic Mustard along roadsides, just as they move viable root fragments of Japanese Knotweed from place to place. Fortunately, it is also fairly easy to pull because of its weak roots.

The ecological consequences of invasive plants extend far beyond botany. Native plants form the basis of healthy ecosystems, supporting the insects, pollinators, and caterpillars that birds rely upon for food. When invasive plants dominate a habitat, biodiversity declines sharply. In some heavily invaded areas, forests become nearly devoid of native spring flowers and young saplings. Roadsides, trails, and disturbed soils become corridors for the continued spread of these aggressive species. In many ways, invasive plants represent one of the great environmental challenges of our era.

Concord's Effort to Control Garlic Mustard

Fortunately, there is hope when communities become involved. In Concord, dozens of volunteers fan out each spring to pull and bag Garlic Mustard before it goes to seed. This includes dozens of high school seniors helping out for community service. Thanks to years of persistence, approximately 25% of the infestation patches we originally mapped are now free of Garlic Mustard! That demonstrates that local action truly can make a difference.

The battle against invasive plants will require continued public education, volunteer efforts, and restoration of native habitats. We need to avoid invasive ornamental species in our

and plant native alternatives that support birds and pollinators. While invasive plants are now part of the modern New England landscape, I believe communities like Concord show that determined citizens can still protect and restore the ecological richness of our native environment.