Garlic mustard sounds like something you’d plant in an herb garden, but it’s actually an invasive species that is smothering forests and harming native plants and wildlife habitats. Metro Natural Gardening Expert Carl Grimm showed us how to keep this pesky plant out of our yards without toxic chemicals.
Garlic mustard is an aggressive invasive plant that we have a chance to keep in check.
• Once established, it spreads quickly across meadows, forest floors and wetlands.
• Its leaves and roots are toxic to forest plants and butterflies.
• In Oregon and many other states, garlic mustard is considered a high-priority weed because we have a chance right now to manage it before it becomes too widespread and too expensive to deal with.
It looks like mustard greens and smells like garlic, usually.
• Garlic mustard is a biennial herbaceous plant – meaning it lives for two years, makes seeds and then dies, and does not have woody stems.
• In its first year it has scalloped leaves arranged in a starburst shape close to the ground.
• In year two it grows a tall stem (up to 4 feet) with lots of four-petaled white flowers and deeply toothed, triangular leaves.
• There are several native look-alikes such as piggy-back plant (Tolmiea menziesii) and fringecup (Temilla grandiflora), both of which have hairy stems and no garlicky smell when you crush the leaves. (But beware, garlic mustard loses its distinctive smell in the fall.)
• Seed pods form in May through September and produce large quantities of tiny, long-lasting seeds that can easily hitchhike on boots, hair and clothes, dropping off later to invade new territory.
Brush off your boots.
• If you’ve come in contact with garlic mustard (especially in summer or fall), avoid spreading the seeds by brushing off your boots and shaking off before you leave the area.
Find it in your yard? Pull it out by the roots and seal it in a bag.
• If you have garlic mustard in your yard, pull it by the root, seal it in a plastic bag and put it in the garbage. Don’t put it in your compost or your yard waste roll cart because the pulled plants have an uncanny ability to produce flowers and seeds. Plant some native plants on the bare spots so you have fewer weeds later.
• Large infestations and ones on public property should be handled by a professional. Generally, the weed is treated with low-toxicity herbicides that help minimize risks to other plants, wildlife and people.
Garlic-mustard pesto is not advised.
• Don’t eat wild garlic mustard. It may have been sprayed with herbicides. And don’t cultivate it in your own garden as it could jump your fence in a heartbeat.
Seen some? Tell your tale.
• Visit oregoninvasiveshotline.org to report sightings of garlic mustard.
• Several organizations offer free garlic mustard surveying and treatment. They may contact you for permission to look for it along backyard streams, roadways and in forested areas.
Ask Metro for more info
• Metro and Oregon State University Extension Service Master Gardeners™ provide free nontoxic lawn and garden resources, including a coupon for hand-weeding tools great for garlic mustard removal, plus information on weed management agencies in your area.
• For more information, ask Metro at 503-234-3000 or visit the 4-County Cooperative Weed Management Area website at 4countycwma.org.