Buckthorn Control Methods

How Buckthorn Spreads

• Even though people aren't planting buckthorn the way they used to, it continues to spread naturally. Buckthorn produces male and female trees, and the female trees produce large numbers of berries each year. Birds and animals greatly enjoy these berries, so wind up spreading seeds widely. This process is assisted by the laxative quality of the berries, thus the "cathartica" in the species' name.

Identifying Buckthorn

• It is very important to know with certainty what buckthorn looks like. Too often, similar native trees such as wild plum and different varieties of cherry trees have been pulled in error. This is particularly unfortunate considering how invasive buckthorn is. It becomes all the more important to preserve surrounding native species.

  Fall is an ideal time to clear buckthorn because it holds its leaves much longer than most other trees and is easier to spot. Its dark purple or orange berries (depending on the variety) also help to identify it, along with its very pronounced thorns. There are many books and online resources available to help with identification. If in doubt, contact your local Department of Natural Resources or Department of Agriculture.

Pulling Buckthorn

• The easiest way to control buckthorn is to uproot the small seedlings by hand. They establish a tough root system, so even this can be strenuous and is best done wearing work gloves. For those seedlings that will not pull out, a garden device known as a "weed wrench" works best to unearth the small tree, roots and all.

  Never try to eliminate buckthorn by simply cutting down the seedlings or trees. They will grow back even more densely. Controlled burning has not proven very effective either.

Chemical Eradication

• For buckthorn trees that have become too large to pull or dig up, or too numerous, the method found to work best is sawing the tree off near the ground and applying an herbicide in full strength on top of the freshly cut stump. Glyphosate (Roundup) and triclopyr (Brush-B-Gon) are two that are frequently recommended. The cut trees then need to be disposed of properly, particularly those still containing berries. Create a contained brush pile or have the brush professionally removed.

Ongoing Control

• As buckthorn trees are removed, it is important to encourage the regrowth of native species through seeding or planting trees. It is also critical to remain vigilant about continuing to pull buckthorn seedlings as they arise, which they will. Buckthorn seeds can remain alive in the soil for years, so eradicating buckthorn requires persistence.

  Also, buckthorn trees are known to release toxins into the surrounding soil, altering its chemical composition and making it more difficult for other plants to grow. Restoration from buckthorn overgrowth is a lengthy process. Helping educate people about buckthorn, particularly those on neighboring lands, will help make the task less overwhelming.