ABOUT GARLIC MUSTARD:

a threat to woodland ecosystems

Garlic mustard is a biennial, herbaceous plant brought to North America from Europe for cooking. Crushing young garlic mustard leaves releases the scent of garlic or onion. Garlic mustard has no natural competitors in North America and can change the chemical balance of soils that native plants thrive in. If left unchecked, Gm will force a declines in Jack-in-the-Pulpit, Trillium, Wild geranium, Bleeding heart, Maidenhair fern, Solomon seal and some tree saplings. When these under story plants disappear, its RIP for native insects, birds, amphibians and mammals.

Take effective action now because colonies of garlic mustard are rapidly advancing into many southwest suburban woodlands -- including Birch Island Woods Conservation Area and Park.

ALERT: Buckthorn removal projects that disturb ground cover and leave patches of bare soil spark the spread of garlic mustard. Gm loves wooded areas that have been disturbed by the likes of grading, clear cutting, trail construction, BMX and mountain bike courses, unleashed dogs and buckthorn pulls. Visit our buckthorn portal for advisories on how to deny Gm an advantage.

FROM A CHARMING FOREST PLANT TO INVADING HORD
First year garlic mustard forms charming, low-laying rosettes of kidney-shaped leaves with scalloped edges. If you see them, be afraid. Be very afraid! During its second spring growing season, garlic mustard can shoot up to four feet high. It’s flocked with rough triangular, serrated leaves and is accented by tiny, white flowers, each with four petals. By early June, second year Gm produces slender seed capsules called siliques that grow on short, tough stalks that radiate from the stem. A single garlic mustard plant can produce from 100 to 7,900 seeds that can hide in the soil for up to five years before germinating. A study of high quality woodlots in Illinois documented clusters of garlic mustard that spread an average of 20 feet per year with some advancing 5 times that distance. The same kind of invasion could be happening just down the street from you.

TIPS FOR STOPPING THE SPREAD OF GARLIC MUSTARD

• Become familiar with garlic mustard’s two-year growth calendar. The Wisconsin DNR garlic mustard download and the Gm websites listed on this page provide excellent guidance on managing the prolific weed.
• The best garlic mustard control strategy is to closely monitor your woodlot. If a few Gm plants show up, get rid of ‘em as soon as possible.
• Choose and prioritize target removal areas using the following criteria:

  1st Priority: Areas that have small, isolated clusters (satellite infestations) or individual garlic mustard plants.
  2nd Priority: Along trails and around native woodland plants like jack-in-the-pulpit and ferns so that they have sunlight and room to grow.

3rd Priority: Larger, connected clusters of garlic mustard (invasion fronts).

• Up-root pre-flowering garlic mustard by hand; shake soil from roots; leave on ground to decompose. Two or three plants can be pulled in a single handful.
• Garlic mustard plants that have flowers or narrow seed capsules can be cut at ground level or pulled. Stuff the stuff into large, plastic yard waste bags for disposal.
• Before pulling Gm in Eden Prairie parks, pre-arrange a pick-up location with the EP City Parks Manager for crews to pick-up the bags of pulled garlic mustard.

HERBICIDES AND GARLIC MUSTARD
Review the materials that are available via links on this page or advisories on killing garlic mustard with herbicide.

BIOLOGICAL CONTROLS ARE BEING TESTED
The University of Minnesota, the MN DNR and other state and federal agencies have formed a Gm consortium coordinated by Cornell University that is searching for a biological control. A European weevil that feeds only on garlic mustard is being tested in a remote section of Minnetonka and elsewhere. The results are encouraging and approval of this method may come soon.

GARLIC MUSTARD LINKS

Wisconsin DNR Garlic Mustard Manual
Click here to download the 2-page PDF version of this succinct, illustrated manual.

Michigan State University Garlic Mustard Website
Thorough, highly recommended, easy-to-read tract on all things garlic mustard (except recipes).
http://www.ipm.msu.edu/garlicmustard.htm/

Minnesota DNR Garlic Mustard Website
http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/garlicmustard.html/

Garlic Mustard Attacks Oregon
“ No deed is too low for garlic mustard, the state's most devious weed-- It's hard to kill, ducks mowers and poisons other plants”
http://www.statesmanjournal.com/apps/pbcs.dll/article?AID=/20080526/INVASIVE09/805260315/

Organize or participate in a garlic mustard or buckthorn pull in the Birch Island district or other park or natural area.
http://www.fbiw.org/JoinIn/BuckthornProgram.htm/

This section was prepared and written by Jeff Strate