Fall is Good Time to Identify and Remove Buckthorn

FOR IMMEDIATE RELEASE
September 24, 2009

Fall can be a good time to identify and remove buckthorn plants, since they tend to stay green later in the fall than many other similar shrubs. It also is a good time for removal since the it may be easier to maneuver in and around the areas they tend to prefer to grow in while other plants are dormant. Non-native buckthorn plants have been known to be a problem in wooded and other natural areas for a number of years, due to their competitive nature.

"In the past few years, it also has been found to contribute to the survival of a field crop pest as an alternate host for the soybean aphid," says John Church, University of Illinois Extension Educator, Natural Resources in Rockford. The aphids feed on soybean plants and can cause stunting and reduce pod set, which means lower yields. It has been determined that at least two types of the exotic buckthorn plants are overwintering hosts for the aphids. Researchers are continuing research on the types of buckthorn that act as hosts and their typical distribution. Buckthorn plants themselves do not invade soybean fields, but can be common around field edges.

In natural areas, exotic buckthorn species shade or crowd out native vegetation. When desirable plants are lost, bare soil is often exposed and susceptible to excessive erosion,

especially on slopes and near streams and rivers. The competitive plants can choke out shrubs, which can reduce food supplies for wildlife and create dense barriers for humans and animals to travel through.

Mechanical removal where plants are sparse, such as individual plants along field edges, is the most expedient and environmentally friendly method. Dig, pull or chop the plants out of

the ground. Buckthorn pulls out most easily up to 3/8 inch diameter. Buckthorn doesn't re-sprout from underground roots, however, cut stumps re-sprout. Foliage on re-sprouting stumps can be treated with herbicides or with fire for several growing seasons. Plants that are cut can also have the stump treated with herbicide which has provided successful control. Researchers at the Illinois Natural History Survey indicate that regular prescribed burning may be especially helpful for areas with abundant numbers of plants. Proper burning permits and safety control measures should be in place before burning.

For further information on control, identification or related topics on buckthorn or the soybean aphid, contact the local University of Illinois Extension office. Related websites include www.ipm.uiuc.edu/fieldcrops/insects/soybean_aphids and

www.inhs.uiuc.edu/chf/outreach/VMG/buckthorn.html.

Source: John Church, Extension Educator, Natural Resources Management, churchj@illinois.edu