Buckthorn |  Construction Damage | Landscaping

Invasive species
Control Measures
Woodland Restoration

Buckthorn: The number 1 most invasive woody plant in Minnesota’s woodlands, is a threat to our upland ecosystems.

Photos and graphics by Luke Skinner

First things first.

Buckthorn is a large shrub, but can grow to become a small tree with a diameter greater than 12 inches.  It has come to out-compete our native plants in the sub-canopy and shrub-layer of woodlands across 68 of 87 Minnesota counties.  The understory species of our remnant woodlands and savannas, parks and woodlots, wetlands and fencerows are all being crowed with buckthorn and displacing our native plants that provide diversity, structure, habitat, and food for wildlife.  European and glossy buckthorn varieties are now listed as restricted noxious weeds in Minnesota.  It is illegal to import, sell, or transport buckthorn in Minnesota.

When words like “noxious,” “weed,” “invasive,” and “eradicate” are the polite words used to describe Buckthorn, you need not feel guilty about getting rid of it. 

Why is buckthorn such a problem?

  • Out-competes native plants for nutrients, light, and moisture
  • Degrades wildlife habitat
  • Threatens the future of forests, wetlands, prairies, and other natural habitats
  • Contributes to erosion by shading out other plants that grow on the forest floor
  • Serves as host to other pests, such as crown rust fungus and soybean aphid
  • Forms an impenetrable layer of vegetation
  • Lacks “natural controls” like insects or disease that would curb its growth

Before you begin killing buckthorn,be absolutely certain that you have identified buckthorn correctly.

You may feel that the whole woodland under-story is invaded with buckthorn, but there are many native species that are routinely being mistaken for buckthorn and removed.  Valuable remnant woody plants that are regularly confused with buckthorn are: American plum, choke cherry, black cherry, hawthorn, nannyberry, and others.  “Brushing” is not an acceptable control method for buckthorn, because areas with severe disturbance are susceptible to further invasive species invasion and erosion.  Ask for help with native remnant plant identification.  Even the smallest native plants can bounce back if properly protected after being released from buckthorn competition. 

Buckthorn reduction priorities for those overwhelmed or with a limited budget·        

  • Survey your site to find remaining native plants. Clear around these plants first. By doing this you "release" native plants from their buckthorn competition. Protect them from being harmed during cutting and removal. Sometimes these natives are very small; but are worth protecting, because when they are freed, they thrive. These remnant plants are the very important local gene pool—plants that are indigenous to your area .   Find a local native plant expert to help you with identification. Use colored flagging tape to mark the native plants to protect.   Protect released natives from deer with wire fencing and bud caps on the terminal buds.
  • Remove female buckthorn first. Mark them with paint or flagging late summer, fall, and winter when full of black fruit, for subsequent removal.  Prevent them from producing one more crop of seed.
  • Protect quality wooded areas that are only marginally infested.


See the following links for more information about Buckthorn and other invasive terrestrial plants, including how to identify and eliminate them:

Minnesota DNR Buckthorn Fact Sheet (excellent ID photos, background, & management info): http://www.nps.gov/plants/alien/fact/rhca1.htm

Minnesota DNR Buckthorn Web Page: http://www.dnr.state.mn.us/invasives/terrestrialplants/woody/buckthorn/index.html

Buckthorn Control Methods:  http://www.dnr.state.mn.us/invasives/terrestrialplants/woody/buckthorn/control.html

St. Anthony Park Garden Club has an extensive section on organizing a community buckthorn removal event; color plates of other Minnesota woody invasives; buckthorn- busting merchandise, plus much more:  http://www.justaddwater.ws.BuckthornHome.htm

Most Invasive Terrestrial Plants in Minnesota: http://www.dnr.state.mn.us/invasives/terrestrialplants/index.html

The Invasive Species Initiative is The Nature Conservancy’s response to abating the damage caused to native biodiversity by the human-facilitated introduction of non-native, harmful invasive species.  This web site provides many resources designed to help all conservationists deal most effectively with invasive species:  http://tncweeds.ucdavis.edu/index.html

The MN Department of Agriculture’s Invasive Species Unit web site includes information on invasive terrestrial plants, insects, and diseases.  Programs, monitoring, facts, guidelines.  http://www.mda.state.mn.us/invasives/default.htm

Woody Invasive Removal Chemicals & Eradication Tools
Find the tools you need right here to eliminate these pests!

Fact sheet:  Chemical Control of Buckthorn

Herbicides for weed & brush control in Natural Areas

Weed Wrench Woody Plant Puller.  Incredible tool for uprooting buckthorn; tested and recommended by many Minnesota buckthorn-busters.  This tool can cause significant soil disturbance (resulting in erosion, uprooting of native herbaceous plants, and exposure of soil to more invasive species).  If using this tool, be certain to shake soil from the roots, replace, and tamp soil back into removal hole. Not recommended on slopes.

Building a Wick Herbicide Applicator (instructions) for buckthorn and woody invasive plant stump treatment.  http://www.mda.state.mn.us/ipm/ticket/volume3no1/wickapplicator.htm

Cut-stump herbicide wand: homemade herbicide applicator wand developed by Jack McGowan-Stinski (TNC Michigan Field Office) as a way to dab herbicides directly onto cut stumps.

Ultra Low Volume Wand (for spraying herbicide on buckthorn trunks)
http://www.arborchem.com/  Click on Ultra Low Volume Wand in left column.

Woodland Restoration Information Native alternative plants for buckthorn.  Includes photos and descriptions of high bush cranberry, nannyberry, chokecherry, gray dogwood, pagoda dogwood, American Hazelnut, bluebeech/American hornbeam, black chokeberry, and juneberry.

The Minnesota DNR Ecological Services Division collects, analyzes, and delivers vital ecological information on Minnesota forest and savanna ecosystems through a variety of programs, publications, and other resources. < face=Times>http://www.dnr.state.mn.us/ecological_services/forests.html

Scientists from Applied Ecological Services have a multitude of restoration project reports and research documented from a wide range of habitats including oak savannas and woodlands.  Extensive information.  http://www.appliedeco.com/NaturalResource.cfm


Construction Damage

Under Construction?   Be Careful.
Care needs to be taken when remodeling or construction occurs near trees.  Without taking appropriate precautions, construction damage can be fatal to trees.  Click here to find out what you can do to protect your trees from construction damage:  http://www.cnr.umn.edu/FR/extension/Constructiondamage.html

Another good site for information on avoiding tree damage during construction and treatment of trees damaged by construction is: http://www.treesaregood.com/treecare/avoiding_construction.asp

Sidewalk and Tree Conflicts
Depending on what city you live in, property owners may be required to pay for the maintenance of the public sidewalk adjacent to their properties, including buckling from tree roots.  Click here for further information on alternatives to standard sidewalk repair methods that make for safe, long-lasting sidewalks and also have minimal impact to stable, healthy trees.  http://www.cnr.umn.edu/FR/extension/sidewalktreeconflicts.html



   Photo courtesy www.mnlandscape.org

Thinking about landscaping your property?  Well, you’ve come to the right place.  When you start the landscaping process, there are many variables to consider:

  • Are overhead wires present?  They could interfere with growing trees and shrubs.
  • How close is the site to roads?  Heavy traffic and salt can affect landscaping.
  • What is the USDA plant zone and how does it impact your landscaping?
  • What trees, shrubs, and plants will grow well in your yard?
  • Is there a concern regarding allergies?

To help you answer these and other landscaping questions, click here:  http://www.plantselector.dot.state.mn.us

How to landscape and impact the environment in a positive way at the same time
You can have a beautiful yard and make an environmental impact at the same time! The Sustainable Urban Landscape Information Series Website (SULIS) explains design principles and techniques.

Sustainable practices in landscaping improve the environment by:

  • conserving resources,
  • reducing chemical applications, and
  • reducing labor inputs

making it less expensive to implement and maintain.

The plant selector portion of the site requires the user to input the plan characteristics they are looking for and queries its database based upon the users’ input.  The implementation section introduces the user to

  • soil amendments
  • planting under trees
  • planting different types of rootstock, compost, etc

It also talks about hardscaping (patios, retaining walls, water features, etc.).  The maintenance section focuses on water, fertilizing, mulching, etc. and herbaceous plants vs. woody plants. 

Click here for the SULIS website:  http://www.sustland.umn.edu/

The Minnesota Nursery and Landscape Association (MNLA) is Minnesota’s largest horticultural trade association, and is dedicated to helping all Minnesotans create beautiful, environmentally-responsible landscapes.  http://www.mnlandscape.org/




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