By Carolyn Plank, Master Gardener
Ah yes, the dreaded B word … Buckthorn! This noxious invasive species threatens residential, woodland areas, waters and grassland areas. Unfortunately, buckthorn control is a multi-year commitment as the seeds in the soil can germinate for many years. So, you ask, how can the home gardener attack this problem?
The best time to find and remove buckthorn is in the fall and early spring. If you are lucky enough to have just a few small plants, you can pull the seedlings and check for new plants every year that may have taken root. For more established infestations, first remove all the berry producing buckthorn on your property as this limits the buckthorn’s ability to multiply. For larger infestations, you may want to remove the buckthorn in sections at a time.
Buckthorn plants that are less than 2 inches in size can be removed by hand or by using an Uprooter or Root Talon. Plants greater than 2 inches in size should be cut at the soil surface using hand tools, chain saws, or brush cutters.
Buckthorn that has been cut at the soil surface must be chemically treated or it will return with a vengeance. Chemical options include treating the stump immediately after cutting with Garlon 3A/Vastlan, Garlon 4, or other brush killers with triclopy or glyphosate (Roundup/Rodeo) to prevent re-sprouting. You can also try non-chemical treatment which includes covering the stump and flare with a tin can or black plastic. Use nails to affix the can or tie to affix the black plastic. If you’re treating buckthorn near water, use an herbicide labeled for aquatic use.
For how and when to dispose of buckthorn, refer to the Minnesota Department of Agriculture’s “Guide to Removal and Disposal of Noxious Weeds in Minnesota.” Many compost sites will also accept buckthorn, but be sure to check with your county for suggestions on disposal. Controlled burning may be an option but will need to be done every 2-3 years. Some cities may haul away your cut buckthorn. Check with your city for their policies.
Finally, buckthorn is a persistent uninvited plant. Even after removal, keep checking your garden for new sprouts and remove them immediately to avoid a larger infestation. There are many hardy and attractive native plants available to fill the areas where you have removed your buckthorn.
For more information on buckthorn removal, click on the following links: