By TJ Boettcher
Former Pheasants Forever
Field Biologist
Many landowners are familiar with the scourge that is buckthorn. Once open forests have turned into nearly impenetrable green walls that line the hillsides from top to bottom. For those that aren’t familiar with it or are unsure of what it looks like, now is the perfect time of year to see the full extent of this green jungle hiding in our woodlands as it is usually the only green plant in the woods after late October. Round, dark green leaves, pea-sized black berries, and a rough, dark bark are also common identifiers.
Buckthorn was introduced from Eurasia as early as the late 1700s to early 1800s. Its first recorded uses were medicinal as the berries contain a laxative that was used to “purge” the body of toxins, sometimes violently. However, it was soon realized that buckthorn grew well in a variety of soil types and environmental conditions and began to gain popularity for use as a hedge or shelterbelt within the nursery industry. Starting in the northeast, plants were shipped west where they were planted as hedges within yards. Female plants produced fruit that were eaten by migrating birds such as robins or cedar waxwings without a second thought as to what happens to the seeds after the birds eat them. Since the berries contain a laxative compound, the seeds quickly passed through the birds and were often dropped in the surrounding countryside where wild populations took hold.
At first, the escaped buckthorn likely went unnoticed in the landscape. A few plants here and there were nothing to be alarmed about, so why bother to remove them? Years passed by and a few female plants matured enough to start producing thousands of berries that contain two to four seeds, each highly viable. More and more seedlings popped up, perhaps going unnoticed amongst the other plants on the forest floor. Eventually, the plants grew taller, often quickly if timber removal occurred. What were once mature forests that one could see through became twisted jungles.
These dense stands can have a ton of negative effects on our landscape socially, economically, and ecologically. Hunters are often some of the first to notice buckthorn. Where deer stands once sat on open ridgetops or valleys where deer could be easily seen up to 100 yards away, buckthorn made it difficult to see a deer at even 10 yards. Another few years and it may be hard to see the deer at all.
From an economic standpoint, an infestation of buckthorn can spell disaster for the regeneration of timber-producing species like oak, hickory, and walnut. These native tree seedlings require a lot of sunlight to reach the canopy. After timber removal, the amount of light that reaches the forest floor is greatly increased. Normally, a few lucky seedlings that somehow avoid being eaten by deer would fill these gaps. However, if buckthorn seedlings are present on the forest floor prior to a logging, they will often become the dominant species to fill these canopy gaps after timber removal since buckthorn is faster growing and shade tolerant. Most of the native seedlings will become stunted or perish.
Finally, buckthorn does not benefit our native plants or wildlife. The dense stands shade out many of our desirable plants. If you’ve never observed this, go find a thick patch of buckthorn and a patch without. Compare what’s growing on the forest floor and you will often find nothing but bare dirt under the buckthorn but a variety of wildflowers, grasses, shrubs, or tree seedlings growing where there is no buckthorn. These native plants are the preferred or sometimes the only food that animals or insects will feed on. Generalists like deer have been observed eating buckthorn leaves, but they often won’t touch the buds. If deer did like consuming buckthorn, we probably wouldn’t have a buckthorn problem.
So, you want to get rid of buckthorn: what can you do? Many people have tried to cut it only to find that it vigorously resprouts from the stump. Others have begun pulling seedlings only to become overwhelmed by the sheer number of them. It’s frustrating. The only sure way to quickly kill buckthorn is to use herbicides or to pull the entire plant out by the roots. Effective treatment options include cutting and treating the stumps with glyphosate (Ex. Roundup) or triclopyr (Garlon 4). Spraying triclopyr with an oil carrier directly on the bark is also very effective. Finally, a foliar application with triclopyr is the way to go for those pesky little plants. Repeated fire, mowing, or grazing are also viable options as they eventually exhaust the plant’s energy reserves, but these options take longer and are often less effective by themselves.
If you’re interested in removing buckthorn or other invasives like, honeysuckle, multiflora rose, barberry, or bittersweet, and would like some direction, please contact the Natural Resources Conservation Service (NRCS). They will have recommendations for herbicide and have a vendor list so you can hire someone to remove the buckthorn. Cost share for removal is also available through the NRCS; call them at 507-724-5261, ext. 3.
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