When buckthorn takes over your site, navigating through your school forest can be a challenge. European buckthorn is a woody invasive species that offers little wildlife value, creates dense and impenetrable thickets, and aggressively outcompetes its native neighbors.
Removing buckthorn and replanting with native species, and guiding understory revegetation will improve your forest's health and create a vibrant place for learning.
Does your buckthorn need to go? Use this opportunity to teach about plant needs and parts, invasive species, habitat, and other topics.You can also remove other woody invasive plants using this plan as a template.
Procedure for removing buckthorn
Too much to handle?
Tackling buckthorn takes time. Be OK if you don't get all of it at once. The experience of learning about invasive species and how to remove them is worth the benefits.If you're working on removing massive buckthorn areas check out our help and funding to find resources. If your school forest is located within the Mississippi River watershed, the Great River Greening habitat restoration group may be able to provide volunteer help.
- Learn about buckthorn by going to the DNR's buckthorn website. Identify and tag where you want to remove it. Ask your forester if you need help.
- Determine what your students can do by looking at age-appropriate buckthorn removal recommendations. Then consider the tools you will need to gather.
- Day one: Take students to the site to learn about buckthorn. Ask them to describe, sketch, or write about what they observe. Ask them if the site looks fun to play in. Where does the forest look dark and scary or open and inviting? Do they notice some tall trees poking up above the canopy…what do they think about those? They may wonder what animals live there…which ones do they observe?
- Day two: After they collect their observations, teach them how to identify the plant. Show them a few buckthorn shrubs and point out parts of the plant: color and patterns of bark, location of thorns, what the roots look like when you pull a small plant out of the ground, berries, height, and other distinguishing features. Give each student a branch (cut with a small lopper or allow students to snap off their own branches) so they can observe closely. Have them draw their branch and label the parts. This step allows you to judge if students can identify and remove the right plants when the day comes.
- Day three: Show students a berry-producing buckthorn tree. Explain that berry-producing trees are the first target because they’re the ones sending out new seedlings. Encourage them to pick a berry and squish it to see the seeds. (Don’t let kids eat the berries. While the berries are edible, mice, squirrels, and birds generally avoid them because they are not nutritious and can have a severe laxative effect.) Then divide students into teams of two or three, give each team some flagging tape, give the class boundaries, and tell them to flag all the berry-producing buckthorn trees they can find. Early fall is a great time to do this.
- Flag off boundaries of where your future buckthorn removal project will take place. Your DNR forester can help you do this. Also identify where you want students to stack trees for winter brush piling or drag cut trees to the road for removal.
- Day four: Do a lesson on invasive species (optional).
- Day five: On buckthorn removal day, show students how to do the work using these age-appropriate buckthorn removal recommendations. Late fall is the best time to remove buckthorn because it is often the only woody plant in the woods that still has leaves and people are less likely to pull up the wrong plant. In the Twin Cities area, the weekend closest to Halloween is ideal. If you plan to remove enough buckthorn so that it needs to be hauled away, call the city ahead of time, tell them your plans, and make sure they can accept cut buckthorn. They may be able to pick it up from your project or chip it on site if it is stacked correctly (trees laid perpendicular to street, cut-stems closest to street).
Chemicals: Immediately treat cut stumps with an herbicide or the buckthorn will resprouts aggressively. Use a Buckthorn Blaster to treat the cambium layer on cut stumps with an 18% glyphosate solution or triclopyr. Check with your school’s safety guidelines if you are unsure about using chemicals near children. It’s a good idea to assign a few adults to handle chemicals and follow students through the woods as they cut stumps. Don’t skip this step! Resprouting buckthorn is not pretty and can result in multi-suckering stumps.Safety: Require anyone using herbicide to watch the Buckthorn Blaster training video.- Once most of the buckthorn is gone, replant the area with beneficial native species that can take advantage of the sunlight now reaching the bare soil. Skipping this step may result in buckthorn coming back. Check with your stewardship plan for species recommendations. The University of Minnesota’s “Cover it Up” project recommends specific plants such as elderberry that can compete with buckthorn. Ask your forester for free Arbor Month seedlings for springtime planting projects. Plan ahead and tell your forester what you need in November.
Age-appropriate buckthorn removal recommendations
Children learn best by doing the work themselves! Here are some suggestions to engage learners from preschool to high school.
Kindergarten – gr. 2: Pull up small seedlings (2 to 6 inches) from infested sites. Show children how to grasp the seedling close to the ground, pull out the roots, and gently shake the dirt off the roots. Children also enjoy pulling out larger plants if an adult pulls it mostly out of the ground first, then letting children use teamwork to pull it the rest of the way. Children can also use teamwork to drag plants to the pile area.- Gr 3-5: Pull small buckthorn seedlings (2 to 24 inches tall) as above, pile seedlings into stacks to make brush pile habitat or for winter burning, pick-up, or chipping.
- Gr. 6-8: Tag plants to remove or keep. Target berry-producing trees first. Use weed wrenches and loppers to remove larger plants, drag plants, stem-first, to pick-up area. (An adult will need to immediately treat cut stems with herbicide to prevent re-sprouting.)
- Gr. 9-12: Use loppers and saws to cut even larger plants. Trained FFA students may use chainsaws. Treat cut stumps with herbicide to prevent re-sprouting. Recent recommendations are to cut stumps a few feet off the ground to make herbicide treatment easier. Use all required safety equipment.
- Adults: Don’t assume they know what they’re doing, even if they say they do! Show adults how to distinguish between buckthorn and similar trees such as cherry or plum, where to cut, and how to daub with herbicide. Ask adults to model appropriate safety procedures.
Removing other invasive plants
While buckthorn attracts the most attention, students can also learn how to control other plants that may be taking over your school forest.
- Non-native honeysuckle
- Siberian peashrub
- Amur maple
- Garlic mustard
- Other invasives (Russian olive, black locust, Siberian elm, etc.) (University of Minnesota)
Tools and safety
These tools are useful for all woodland management projects. Consider
- Heavy gloves – ask families to provide
- Closed-toe shoes or boots – ask families to provide
- Safety glasses
- School liability waivers for volunteers
- High-visibility safety vests for students and volunteers
- Flagging tape for marking boundaries, tagging trees to remove (use another color for trees to keep)
- Depending on the age of your students: weed wrenches, loppers, saws, chain saws (your local soil and water conservation district or DNR office may be able to connect you with these tools)
- Buckthorn Blasters. These are safe pesticide applicators for high school students or adults. Make sure students and adults know how to use Buckthorn Blasters effectively. Registered school forests can request some from the School Forest Program.
Teaching about invasive species.
The concept of invasive species is best taught in grades 6 and up.
Plants and animals have migrated all over the planet for eons. A native species is one that evolved in specific conditions and with other native species that interact with it. An introduced non-native species can have an unfair advantage over a native species when it arrives in a space with no natural enemies or has a longer growing season.
Some native species can be aggressive too. For example, poison ivy, while native to Minnesota and beneficial for wildlife, can be hazardous to some people. Urushiol, the oil that can trigger severe skin blisters, is present on all parts of the plant all year round. The safest way to remove poison ivy plants requires chemical treatment. Do NOT allow students to attempt to remove it.
Remember, not all non-native species cause problems. For example, people have introduced beneficial plants such as apple trees that provide beauty, food, and entire industries. When teaching about invasive species, be sensitive to students who are from families who are new to this country.
Invasive Species Lesson (middle school)
STEM strategies for teaching about invasive species (middle/high school)
Minnesota Academic Benchmark Connections
(Life Science) Developing possible explanations of phenomena or designing solutions to engineering problems. 4.1.2 Students will be able to argue from evidence to justify the best solution to a problem or to compare and evaluate competing designs, ideas, or methods.* 5L.4.1.2.1 Evaluate the merit of a solution to a problem caused by changes in plant and animal populations as a result of environmental changes.* (P: 7, CC: 4, CI: LS4, ETS1) Emphasis is on evaluating solutions (based on evidence and design criteria and constraints), not developing new solutions. Examples of environmental changes may include land characteristics, water distribution, temperature, food availability, or the presence of other organisms.