Buckthorn Removal Methods
To be able to remove Buckthorn, you will need to know what to look for first.
Common Buckthorn
Leaves
Common or European Buckthorn leaves are oval shaped and rounded teeth (the leaf has a round pointy edge). They also have 3-5 curved veins on the inside of the leaf.
Easy ways to spot
The easiest time of year to spot common Buckthorn is in the fall. This is because this type of buckthorn stays green, even in some cases into November, while the other plants around it change colors or lose their leaves.
Rhamnus cathartica (Common Buckthorn): Minnesota Wildflowers
Glossy Buckthorn
Leaves
Glossy Buckthorn leaves are egg shaped with the widest end of the leaf towards the tip. The edged of the leaf can be smooth or wavy with many veins (the lines inside the leaf) that just barely curve.
How to spot
This type of buckthorn is tricky because in the fall it's leaves change color and fall like native plants do. The leaves can look literally glossy/waxy look, but they can look dull.
Invasive vs native
Be careful as Glossy Buckthorn can look like native cherries especially by bark. The easiest way to differentiate the plants is by the leaves. Cherry leaves are widest near the middle of the leaf and have jagged edges. They also have glands at the base of the leaf on the stem; these glands look like two dots or bumps. They have been known to have brown fuzz along the veins on the bottom of the leaf as well.
Frangula alnus (Glossy Buckthorn): Minnesota Wildflowers
Removal Methods
Cut and Treat- great for most occasions
This method requires herbicide (ideally in a dauber bottle for easy application), a hand saw, and loppers. First step is cut the buckthorn horizontally and 2-3 inches from the ground to prevent someone tripping over the stump and injuring themselves. Next, dab the herbicide around the outer part of the stump avoiding the middle of the stump. You should be wearing the recommended PPE and handling the herbicide the way it indicates on the herbicide label.
Hack and Squirt- for big tree-sized buckthorn
This method also requires herbicide but instead in a spray bottle, and a hatchet. First, using a hatchet, cut downward through the bark at a 45-degree angle. This is to create "wells" around the tree trunk but be careful not to remove bark. Next, insert the herbicide into the wells with a spray bottle while being careful of runoff to prevent other plants and the soil from contamination.
Using Hack-and-Squirt Herbicide Applications to Control Unwanted Trees
Cut High- for those that don't want to use herbicide or for small projects
For this method you'll need loppers, a hand saw, and time. This method happens over a course of two years, because you are essentially starving the tree of its energy stores until it can no longer sustain itself.
- Cut off the main growth meaning all branches and leaves and make sure only a tall empty stump is left behind.
- Allow the buckthorn to resprout and then next season, remove all the leaves again.
- Repeat this until the stump no longer resprouts or leafs. The stump should be easy to push over within two years.
- Plan for and plant with a cover-it-up seed mix and mixing in native trees and shrubs. Pull any buckthorn seedings found as they can remain dormant for a long time in the soil.
Cover It Up Project- after removal
After using any of the above methods, the cover it up project assists reestablishing native plants with plants that suppress aggressive buckthorn seedlings. Native wild rye grasses can prevent buckthorn seedlings from sprouting and stop deer from tracking other invasive seeds into the soil.
check out Guide-to-forest-understory-revegetation-buckthorn-2024 from the UMN for the recommended species list and more information