Taking Back the Landscape From Thorny Invaders

“Barberrians at the Gate!”  declared Fred Balling as a group of 30 fellow Cornwallians, some gloved and armed with bypass loppers, met in front of a residential property to learn about the methods to identify and remove Berberis Thunbergii, or invasive barberry.

Organized by the Garden Club in Cornwall, Conn., with the support of the Cornwall Conservation Trust and the Cornwall Conservation Commission, the talk and demonstration were led by two Garden Club members: Heidi Cunnick and myself, Dee Salomon.

“Our Garden Club events usually center around what to put into the ground,” I said as I introduced the event. “But today we are going to talk about what to take out of the ground.”

We tried to impart a sense of urgency around barberry removal in the talk that preceded the hands-on demonstration.

Barberry not only prevents people from accessing the woods due to its needle-sharp thorns — but those thorns also act as a protective dwelling for mice from predators.

As mice proliferate so do Lyme-carrying ticks. Barberry elimination reduces tick populations by as much as 60%.

Heidi provided another statistic that appeared to make an impression amongst the attendees: Researchers have found 82% fewer native tree recruitments (the establishment of seedling trees) in barberry-infested forests.

Given the demise of native tree species such as chestnut and elm, as well as current risks to beech, hemlock and ash, we could end up with fields of barberry where there was once a forest.

And with that, Heidi identified barberry, along with bittersweet vine, burning bush and Japanese honeysuckle as stealthy invaders of a front yard garden. The group then walked into the woods, inspired to tackle the barberry on the site.

Weapons for our
war on invasives

Heidi brought a heat flame tool (Weed Dragon Propane Torch, approved by the Garden Club of America for home use), a weed-whacker with a brush cutter attachment (Ryobi) and a weed wrench. The latter was demonstrated on a burning bush, as the multi-stemmed barberry is not well-suited for the wrench.

Of all the tools, the most practical and least costly is a simple pair of long-handled clippers or bypass loppers.  There were enough loppers, and enough barberry, for many to participate by cutting the stems of the barberry about 2 inches above the soil.

Why glyphosate works

The bright yellow color of the barberry stem interior is a hallmark of its identity and made the next step of the process — the careful application of a dab of glysophate herbicide — easier to demonstrate. Tinted blue, the yellow tips turned a bright blue-green after the application of the herbicide.

Heidi stressed the importance of understanding the risks and proper use of glyphosate. She had information sheets to hand out along with a few of the applicators, called “buckthorn blasters” that were ordered from NAISMA, the North American Invasive Species Management Association.

“Dee and I have been talking for over a year about how to motivate people to take responsibility for eradicating invasives on their property,” Heidi said. “People often don’t realize the extent of devastation that a handful of invading plants can cause.

“The invasives that harbor ticks have health implications for ourselves and can drive down property values. We want people to access their land and enjoy the beauty that comes from being stewards of their woodlands.”

For information on identification and eradication of local invasives, go to the Connecticut Invasive Plant Working Group https://cipwg.uconn.edu.