Invasive Species

An invasive species is any kind of living organism not native to a specific location. Invasives cause harm by outcompeting native species and eventually disrupting ecosystems.

According the the Minnesota Department of Natural Resources, a number of invasive species (such as zebra mussels, Eurasian watermilfoil, common buckthorn, and emerald ash borer) threaten the state's ecosystem. Managing invasive species and establishing native vegetation are goals of the City's Natural Resources Management Plan.

Managing Invasive Species

Buckthorn

Buckthorn is a non-native shrub brought from Europe in the mid-1800s for use as a hedge or windbreak plant. It forms dense thickets and will out-compete native shrubs, tree seedlings, and perennials such as wildflowers for sunlight, water, and soil nutrients. Buckthorn became a restricted noxious weed in 2001 and can’t be purchased in Minnesota.

Common buckthorn and glossy buckthorn are the two species of interest. They can be easily identified because they leaf out earlier in the spring than most native plants and retain green leaves well into November. Berries have a laxative effect on birds and seeds are distributed widely each year. Seed can remain alive in the soil for more than six years.

Removal

Buckthorn can be removed by mechanical and chemical methods. Control will take several years and usually cannot be done in a single season. The most effective time for buckthorn removal and control is late summer through fall. Proper identification is important so that native shrubs, such as American plum, chokecherry, or grey dogwood, are not removed by mistake.

First remove the berry-producing plants. Plants can be pulled out of the ground with a weed wrench or by hand, or by cutting and treating the stumps with herbicide. Residents can borrow a wrench for up to seven days from the Physical Development Department.

The leaves of small shrubs can be treated with a foliar spray in late summer through the fall season. Stumps can be treated with a glyphosate herbicide immediately after removal. Use rodeo brush herbicide or equivalent when working near water or wetlands. Always use chemicals in accordance with the law and the product label.

Weed Wrench Program

The City of Golden Valley has weed wrenches available for use by residents. They can be checked out for up to seven days and picked up in the Physical Development Department in the lower level of City Hall during office hours (Mon - Fri, 8 am - 4:30 pm). When borrowing a wrench, residents must leave their name, address, phone number, and a $25 security deposit, which will be returned when the wrench is checked in.

If you want to remove buckthorn on City property, check out this map showing where you can volunteer. Then fill out a volunteer form and email it to the assistant City forester.

Resources

Garlic Mustard

Garlic mustard is an aggressive biennial herbaceous (or herb) plant, which means it does not flower until its second year and then it dies. It grows in a way that crowds out native wildflowers, tree seedlings, and woodland plants and can totally dominate a woodland within five to seven years. This invasive plant species can be found throughout Golden Valley.

Removal

Garlic mustard can be managed by pulling up the second year plants before they flower and produce seeds, typically in early spring. Even though it is a prolific seed producer, garlic mustard can be managed by preventing seed production of plants over several years. Managing this species takes a strong commitment once it becomes established.

Garlic mustard in the Bassett Creek Nature Area

Because flowering garlic mustard can spread seeds even after it's been pulled up by the roots, the Minnesota Department of Agriculture (MDA) asks that you bag the plants in paper bags as you weed them. Bagged plants should dry thoroughly before disposal by burning, burying deeply in an area that will not be disturbed, or landfilling, according to the MDA.

If you want to remove garlic mustard on City property, fill out a volunteer form and email it to the assistant City forester.

Fun Fact: You can also use garlic mustard to make a tasty dish.

Resources