Can an ornamental bush displace native plants, degrade wildlife habitat, and alter forest soil? In the case of Japanese Barberry, the answer is yes.
Once favored for hedging and erosion control, The National Park Service now lists Japanese Barberry as one of its “least wanted” plants. This compact, spiny shrub has spread from managed landscapes into natural areas.
Its red berries make it easy to spot in November. The clusters of glossy, oval-shaped fruits covering the plant are the source of its mobility. They are eaten by birds and small mammals, which disperse Japanese Barberry seeds into new locations.
The hearty plant is able to sprout at an alarming rate in poor soil and shade. And since neither deer nor insects feast on the leaves and berries, they have a competitive advantage.
In the northeast, dense Japanese Barberry stands are a common site in our wooded areas, where they can quickly establish under a closed canopy, displacing native plant species and degrading wildlife habitat. On heavily invaded sites, Japanese Barberry can alter soil pH and nitrogen dynamics.
Eradication efforts are labor intensive because pesticide use needs to be limited.
“Obviously we can’t do blanket sprays because it would kill other things as well,” says University of New Hampshire landscape horticulture specialist Cathy Neal. “So typically, it’s a question of both cutting and hand removing and then doing a cut stem treatment where they just apply a weed killer to the cut stem after someone cuts it and removes it.”
Work is being done at the University of Connecticut to breed genetically sterile barberry plants. That way, they can still be used for ornamental purposes, but not pose a risk of spreading. That will only be an option is states that don’t outlaw the sale and planting of barberry.
Barberry is a good example of an invasive plant that despite our good intentions has spread into native forests, with harmful effects.
Photo: courtesy of Colorado Art Studio/via Flickr