State scientists believe removing a common, invasive shrub called Japanese barberry (berberis thunbergii) can help reduce the Lyme disease-carrying tick population by as much as 60 percent, but they told the NBC Connecticut Troubleshooters it takes work.
Japanese barberry is inexpensive, changes color with the seasons, and grows quickly, all reasons experts told our team it has remained popular with homeowners and landscapers.
Researchers at the Connecticut Agricultural Experiment Station (CAES) warn it can transfer quickly from gardens to the wild, and they said they have frequently found it in woods bordering lawns, and beside hiking trails and roads.
Once established, Japanese barberry spreads rapidly and can crowd out young trees and wildflowers, forming dense thickets where they said their research showed the Lyme disease-carrying tick population is on average 12 times higher than in forest without it.
University of Connecticut Professor Tom Worthley travels around the state demonstrating methods to kill off the shrubs, and explained to our team that Japanese barberry is so resilient, “just cutting it doesn’t control it,” and that the shrub is able to re-sprout from roots left in the ground, as well as from branches that have been cut and left behind.
Worthley and CAES scientists advocate a set of methods homeowners can use to remove Japanese barberry from their homes and wooded areas, including the use of a propane torch or flame-weeder directed towards the base of a barberry. They said cooking the base of the barberry bushes can prevent new sprouts from coming up, but is dangerous without the appropriate training and gear. Instead, Worthley said, pulling the bushes out with chains or a weed wrench can be effective too.
The easiest option they recommended for homeowners may be to cut Japanese barberry bushes to its roots, and return to cut new growth every few months. This can take over a year, but Worthley explained repeatedly cutting it down will, “eventually exhaust the plant.”
The experts suggested homeowners can apply herbicide, available in many garden centers, to the base after cutting to speed the process up. Worthley cautioned homeowners to be wary of over-spraying and potentially harming native plants and wildlife.
The experts reminded homeowners considering removing Japanese barberry from their properties to always use protective gear when using power tools and chemicals.
Japanese barberry is commercially available in a variety of colors including lime green, orange, and crimson, but is generally a bright green in the wild for most of the year. It has thorny branches and oval leaves with smooth edges.
For more information on removing Japanese barberry and its effects on the environment, click here.