October Weed of the Month: Invasive Plants in Grasslands

Prairies are one of the most threatened ecosystems in the world. Before European settlers arrived in Minnesota, there were 18 million acres of prairie. Now just one percent remains. Grasslands are highly beneficial ecosystems, and having a healthy plot of native species on your property can directly benefit you. Invasive plants such as spotted knapweed, leafy spurge and common tansy can overtake grasslands. It is best to find and control these invasive plants before they outcompete prairie plants.

Creating a management plan for your grassland

1. Determine the size of the area you want to manage. Understanding your site will allow you to better plan for success. What existing plants (native and invasive) are there and what plants will thrive in this area?

2. Do your research. Visit remnant prairies in your area and record what species are naturally found there. What nonnative species are in this area? Common invasive species in grasslands include: knapweeds, wild parsnip, Siberian elm, leafy spurge, Queen Anne's lace, and many others. Experts know which invasive species are prone to your area and can help identify target species and management ideas.

3. Create a plan. A well designed and well executed plan will aid in success. When creating a management plan, you need to ask: what is the end goal, what is my budget, and what plants do I want to see in this area? Once the management plan is finalized, implement it and stick to what was intended. There are a variety of management techniques to consider.

o Consult your University of Minnesota Extension office regarding herbicide recommendations and uses. Herbicides can provide time and cost effective solutions for invasive species management.

o Mechanical treatment (hand pulling and mowing) can be an effective method to remove or reduce target plants. Wear proper protection, such as gloves and long sleeves, before attempting to mechanically remove.

o Biological control is an option for large, undisturbed leafy spurge and spotted knapweed infestations.

4. Grazing is effective with targeting specific plants. Goats tend to target woody and herbaceous plants before grasses.

5. Monitor progress. Monitoring your grassland is imperative to success. You need to understand how the vegetation is reacting to your management techniques. Is your woody vegetation growing back? Are there new invasive plant species? Periodic monitoring allows you to change/adjust your management plan to meet your end goals.

6. Continue with invasive management, prescribed fire, mowing/grazing. The native plants in your grassland have evolved to these management conditions, and for them to thrive they need to continue to live in those conditions.

There are management templates, experts and volunteers, grants, and land management companies that can help with prairie restoration and management. With persistence and some maintenance, it is possible to improve the overall health and sustainability of your grassland.