The Good Fight: Controlling Invasive Plants

We all like to see healthy plants across the landscape, but not all plants contribute to a healthy environment. The Massachusetts Invasive Plant Advisory Group has identified 66 plant species that are invasive in our region. They were introduced from other parts of the world and they thrive here, out-competing or displacing native plant species, and disrupting food sources and habitat for wildlife.

Based on an assessment of the invasive plants on our conserved lands, Kestrel’s stewardship team has been making targeted efforts to deal with them. As part of that work this spring, we focused on six of our properties in Hadley, Amherst, Pelham and Belchertown. Nine Land & Trail Crew members volunteered 22 hours of their time to fill 14 large bags with aggresive invasives like Japanese knotweed, black swallowwort, Japanese barberry (the “angry” bushes in the header photo above), multiflora rose and garlic mustard. In several locations, we’ve all but eliminated the targeted invasives. In others, the work is challenging and control of the plants will require ongoing annual pulling and monitoring.

Here’s the report from our TerraCorps Land Stewardship Coordinator, Eli Smith:

Based on a 2015 assessment of our properties, we selected where to focus our efforts based on these management goals for invasive plants:

• Prevention – Early control of newly arrived or potential infestations
• Containment – Restrict distribution and spread within a defined area
• Control – Suppress abundance to a level that allows native plants to exist or thrive
• Eradication – Complete removal long‐term within a defined area
• Deferment – No active management at present due to scale of infestation, presence of large seed sources on abutting properties, or other factors that make success unlikely

This spring, we continued work on several of our focus properties:

PROPERTY: Dyer Conservation Area, Hadley

GOALS: Containment & Control. Contain moderate infestation currently concentrated around field & wetland; prevent further encroachment into upland forest; control within forest.

PROGRESS: 2018 efforts to remove Japanese barberry and winged burning bush seem to be successful, with few plants found in 2019.  However, oriental bittersweet has moved into the target location, so we will keep returning every year to keep invasives from marching into the forest!

PROPERTY: Gurvitch (New England Trail), Belchertown

GOALS: Eradication & Prevention. Eliminate small infestation of young plants (mostly garlic mustard) at property edges & monitor edges & trail to prevent re‐infestation.

PROGRESS: Mostly free of invasive plants! After a few seasons of pulling garlic mustard, we did not find any on the property this year! We will continue to monitor to prevent re-infestation.

PROPERTY: Dorie Goldman Trail (Amethyst Brook), Pelham

GOALS: Containment & Control.  Control moderate infestation of Japanese barberry within the lowland area along the trail & stream, preventing encroachment into upland forest.

PROGRESS: Control is challenging here — this year, in one workday we removed and filled 5 large contractor bags full of barberry.  We will focus our efforts on keeping an access point open to the brook, and preventing infestation of the upland forest above the stream.

PROPERTY: Well-Away Farm, Pelham

GOALS: Containment & Control.  Over the years, we cleared part of a large Japanese barberry infestation around the bridge crossing the stream. The goal is to keep that area clear of invasive saplings attempting to re-infest.

PROGRESS:  The area around the bridge has seen growth of native plants such as birch, skunk cabbage, and red trillium. This year, after two workdays, most of the invasive growth (including Japanese barberry, multiflora rose, and winged burning bush) in the cleared area around the bridge was removed and pushed back.

PROPERTY: Katch-Ferro-Edman, Hadley

GOALS: Containment & Eradication. Contain moderate infestation of purple loosestrife to wetland. Eradicate small infestation of other species in upland forest & monitor to prevent re‐infestation.

PROGRESS: Success! After initial efforts to clear invasive plants, we continue to monitor and rarely find an invasive species. We will continue to visit and pull any new invaders.

PROPERTY: Wood Cousins, Amherst 

GOALS: Control Black Swallowwort & remove single patch of Japanese Knotweed.

PROGRESS: Japanese Knotweed has been removed! Black Swallowwort is being controlled through annual pulling and monitoring.

Big thanks to all of our volunteer Land & Trail Crew members who came out to our workdays this season and every season. Your efforts make a difference and we couldn’t do it without you! If you want to learn more about how to control invasive plants in your own yard, visit Massachusetts Natural Heritage & Endangered Species Program page on invasives.