What is Buckthorn?

Common buckthorn was first brought to Minnesota from Europe in the mid-1800s as a very popular hedging material. Shortly after its introduction here, it was found to be quite invasive in natural areas and in the 1930’s the nursery industry stopped selling it. However, many buckthorn hedges may still be found in older neighborhoods throughout Minnesota. European or common buckthorn and glossy or alder buckthorn are listed as restricted noxious weeds in Minnesota, meaning it is illegal to import, sell, or transport buckthorn in Minnesota.

Why is Buckthorn such a problem?

Buckthorn invades natural areas and out-competes native plants for nutrients, light, and water. Buckthorn has no natural disease or insect predator to keep its population under control. It prevents native trees from regenerating by shading out the forest floor and also contributes to soil erosion.

Healthy Forest Floor

Buckthorn Invaded Forest Floor

Do you have Buckthorn?

Shady areas that are not mowed or actively managed may have buckthorn. The invasive shrub is spread by birds that eat buckthorn berries. The berries act as a laxative in birds and seeds are quickly deposited in new locations.

Do you want to get rid of it?

Buckthorn removal is a multi-year process. The seeds from a buckthorn plant can continue to sprout up to six years after they have fallen from their parent plant! Buckthorn control is possible and will benefit the entire urban forest community.

Where to Start

The information on this page will provide you with information on how to identify, remove, treat with herbicide and what to do when buckthorn is gone.

How to Identify Buckthorn

One of the most important steps in removing buckthorn is figuring out whether or not you have it on your property! Identifying buckthorn is pretty easy. If you think it looks like buckthorn, it probably is.

General Appearance

Buckthorn leafs out earlier in the spring and keeps its leaves much later in the fall than other trees and shrubs.

 
Leaves and Berries

Buckthorn leaves are glossy with deep leaf veins. Leaf edges have small teeth. The leaves are almost directly across from one another and there is a thorn at the top of the twig.

Bark and Trunk

The bark of buckthorn trees is gray in color. Older trees or larger branches have flakey bark while younger trees or smaller branches have smooth bark with raised white bumps. Look for yellow sapwood under the bark.
  

Removing Buckthorn by Pulling

Buckthorn removal can be an overwhelming process. The best way to start is by evaluating your property. Mark any valuable trees on your property to avoid damaging or accidentally removing then. Removing and controlling buckthorn will be a multi-year process. Do not feel like you need to eliminate it all at once. To see the best way to prioritize your buckthorn removal is to remove the female plants that produce the seeds.  Removing the larger tree and fruit producing plants will reduce the amount of new seedlings.

Pulling buckthorn is the best method if:

• If the buckthorn is small (1.5” in diameter or less);

• If there is little desirable native plants in the area that may also be uprooted;

• If the removal area is not sloped

Buckthorn can be pulled by hand or with a tool. After pulling buckthorn, shake the dirt from the roots and avoid allowing the roots to contact the soil, where it may be able to continue to grow. Make sure to firm up the soil that was disturbed by lightly tamping it down with your foot.

Tool Rental from the City of Farmington

One tool that makes pulling buckthorn much easier is a weed wrench. This tool is available for a one week rental from the City for a refundable deposit of $150 dollars. This is available first come first serve, call the Engineering Department to reserve at 651-280-6840.

Removal Method - Cutting and Herbicide

As mentioned above, buckthorn removal can be overwhelming. Again, you can prioritize your buckthorn removal by removing mature seed bearing plants and working your way to smaller plants.

Cutting and herbicide is the best method if:

• Buckthorn is fairly large (1.5” in diameter or larger);
• The area has sloped ground;  
• In areas with many native plants that you don’t want disturbed

Treat with Herbicide Immediately After Cutting

Buckthorn will grow back worse than before if you do not treat the cut buckthorn stumps. It is best to treat the stumps within a few minutes of being cut. If not, the stump may seal off and not take in the chemical. Make sure to use herbicide with the active ingredient Glyphosate (25% or greater concentration) or Tricopyr (active ingredient 8% or greater concentration). Make sure to read the handling instructions before use!

Caution: Do not use these herbicides in or near water or waterways. If you will be working near water, ask for Rodeo® or an equivalent herbicide at 25% or greater concentration.

Tips on Herbicide Use:

There are two big concerns when using herbicide, personal safety and minimizing any herbicide damage to other nearby plants. Also remember to:

• Treat the stump within minutes of cutting. The stump will begin to seal itself off and may not absorb the chemical if you wait too long.

• Always read the instructions on your herbicide bottle carefully.

• Wear personal safety gear, including long sleeves, long pants, gloves and eye protection.

• Be aware of wind direction and any potential spray drift that could be a hazard to yourself and others.

• Keep an arm’s length away from whatever you are spraying but hold the spray bottle close to the stump.

• Adjust spray nozzle so you can spray the stump without either missing the stump or spattering off of the stump too much onto nearby plants.

Disposal of Buckthorn  

Need to dispose of your buckthorn? Only certain yard waste composting facilities accept noxious weeds. These composting facilities should have the national Seal of Testing Assurance ensuring that the facility composts at 131 F for at least 15 days, which is required to destroy the noxious weed material.

One composting site that has the Seal of Testing Assurance for noxious weeds is SET & The Mulch Store. To look for other sites check out the USA Composting Council’s map at STA Certified Compost Participants Map.

In general, it is best to kill noxious weeds and allow them to decompose on-site to prevent seed spread. If you must remove the material, contact yard waste facilities to see if they accept noxious weeds. Transport is only legal for disposal.

A Guide to Removal and Disposal of Noxious Weeds in Minnesota | Minnesota Department of Agriculture (state.mn.us) 

Replacement Plantings

Now that you are working on ridding your property of buckthorn, you may want to start replanting with trees, shrubs and wildflowers that are native to Minnesota. Check out the list of native plants.  

Where can I buy native plants?

The best place to buy native plants is a store that specializes in their growth and care. The DNR has an updated list of approved native plant vendors and landscapers.

Companies on the DNR’s list have certified that they sell Minnesota native plants sourced from the state, do not sell invasive or noxious plants, and/or have experience as a native plant consultant or habitat restoration specialist.

Buckthorn Seedlings

Once you have all the large buckthorn under control you can start to tackle the little stuff. Keep an eye out for any seedlings that try to come back; it’s a lot less work to pull out a seedling than to cut down a mature buckthorn!

 

Additional Resources

Minnesota Department of Natural Resources - Buckthorn page