What you can do to control buckthorn!
Controlling seedlings or small buckthorn plants
For individual plants
If less than 3/8 inch in diameter, remove by hand. Small seedlings can be pulled and will not re-sprout. If greater than 3/8 inch, use a hand tool that pulls the shrub out, such as an "Uprooter" or "Root Talon". Removing by hand is easier if the soil is moist. Before you pull or dig buckthorn out of your soil, Contact Gopher State One Call (1-800-252-1166) to ensure there are no buried utilities in the area. Be aware of minimizing soil disturbance and tap soil and plants back into place after pulling plants.
If pulling individual plants is impractical
Spray foliage of short buckthorn or seedlings with a herbicide. Glyphosate (one brand name is Roundup) will kill all actively growing vegetation on which it is sprayed. Triclopyr will kill broadleaf plants and will not harm grasses when applied properly.
Controlling large buckthorn
Buckthorn plants that are two inches in diameter or larger, are best controlled by cutting the stem at the soil surface and then cover or treat the stump to prevent re-sprouting. This can be effectively done with hand tools (for a few plants), chain saws or brush cutters. If only cutting a few stumps they can be covered with a tin can or black plastic (such as a "Buckthorn Baggie") to prevent re-sprouting. Otherwise, stumps should be treated immediately after cutting (within 2 hours) with a herbicide containing Triclopyr (such as Ortho Brush-B-Gon or Garlon 3A or 4) or Glyphosate (Roundup) to prevent re-sprouting.
The best time to cut and chemically treat the stumps is in late summer and throughout the fall. Avoid treating buckthorn in May and June when the tree is putting out leaves as the herbicide will be less effective at this time then during the rest of the year. Herbicides can be applied to cut stumps with a paint-brush, wick applicator or a low volume sprayer. When using water-soluble herbicide products like Ortho Brush-B-Gon, Garlon 3A, or any of the Glyphosate products, treat only the cut surface. When using oil-based products like Garlon 4 or Pathfinder II, treat the cut surface and the remaining bark to the ground line. In cases where more than a few plants are treated, add an indicator dye (available where pesticides are sold) to the herbicide to mark cut stumps you have sprayed. Colored flags can also help mark cut stumps. When buckthorn is cut, the stumps are easily covered and lost under cut brush.
Chemical treatment in the winter: Buckthorn can be treated throughout the fall and winter. Follow herbicide label instructions regarding temperatures at which the herbicide can be applied. Water-soluble herbicides like glyphosate (Roundup, Rodeo, etc.) or triclopyr amine (Garlon 3A, Brush-B-Gone, etc.) can be applied to cut stumps when the temperature is above freezing (32 deg. F). Oil-based products of triclopyr ester (Garlon 4, Pathfnder II) can be applied when the temperature is below freezing (below 32 deg. F).
For basal stem treatment, a method that applies chemical through the bark, low volume spray applications can be made with Garlon 4 and similar oil-based products. This application method uses Triclopyr ester mixed with an oil diluent ( i.e. Bark Oil Blue, kerosene or diesel oil) applied directly to the bark of buckthorn from the root collar up about 12-18 inches. This treatment works best on stems less than 2-3 inches in diameter. An ultra low volume spray wand should be used to minimize herbicide use and reduce the potential for non-target injury. Buckthorn treated in this fashion can be left standing or cut at a later date.
Note: Buckthorn seeds in the soil can remain viable for up to five years. Follow-up control of seedlings that emerge after initial control efforts is important on all sites. With no follow-up control, buckthorn will come back. Fire offers a long-term management option in grassland or savanna cover-types. Burning will need to be done every two to three years. If burning is not an option, a follow up treatment of the seedlings (pulling or spraying) is needed.
After buckthorn control, many sites may require replanting of desirable tree, shrub, and herbaceous species. A resource that may help you to find the right plants for your location is a multimedia CD program called Restore Your Shore.
Herbicides to Control Buckthorn
|Trade Name||Chemical Name||Concentration||Use|
|Ortho Brush-B-Gon||Triclopyr amine||Ready to use - do not dilute||Cut stump|
|Ferti-Lome Brush Killer and Stump Killer||Triclopyr amine||Ready to use - do not dilute||Cut stump|
|Garlon 3A||Triclopyr amine||Mix one part Garlon 3A with 3 parts water (this achieves a 25% solution)||Cut stump|
|Garlon 4||Triclopyr ester||Mix one part Garlon 4 with 3 parts bark oil/diluent (this achieves a 25% solution)||Cut stump or basal bark|
|Pathfinder II||Triclopyr ester||Ready to use - do not dilute||Cut stump or basal bark|
|Roundup, Rodeo, Accord, Etc.||Glyphosate||
||Cut stump or foliar spray|
Always read and follow the instructions and precautions on the herbicide label.
Reference to chemical brand names and other product brand names in this column does not imply endorsement of those products. The herbicides listed in this article may be available under other brand names with the same active ingredient that are equally effective.
Biological control: There has been research to find biological control insects for buckthorn, but no suitable insects were found.
Additional management information:
- Use the MIPN Control Databaseto find specific management recommendations for your type of site and experience level.
- Buckthorn: what you should know and what you can do
- Buckthorn management - city of Minnetonka handout