The Mustard Family Invasives

Written by Kathy Breznau

Invasives in the Mustard Family

Rockford, Michigan is home to two particularly invasive species from the Mustard Family: Garlic Mustard and Dames Rocket.

Although they can look harmless, invasive species crowd-out other plants and can quicky take over beautiful landscapes, stifling biodiversity.

Garlic Mustard (Alliaria petiolata)

Garlic mustard is a high-priority invasive species, especially here in Rockford. Large infestations of this low-growing herbaceous flowering plant limit growth and productivity of native plants and threaten the long term health of forests—including the beautiful areas along the White Pine Trail and Rum Creek—limiting how we enjoy them now and in the future.

According to Illinois Extension, “Garlic Mustard’s early spring growth can quickly cover the forest understory. Infestations take away light, water, and nutrients from wildflowers and tree seedlings, threatening insects, wildlife and future forests.”

How to identify Garlic Mustard:

Dame’s Rocket (Hesparis matronalis) 

Dame’s Rocket is also part of the mustard family! Like garlic mustard, Dame’s Rocket is an aggressive invasive species that spreads easily on many sites.

A single dame’s rocket plant can release 20,000 seeds – hence why it spreads so rapidly! Unfortunately, this can lead to the replacement of native plants, disrupting the local ecosystem and displacing native insects that depend on native plants. Insects are a critical food source for the birds we so love, especially during this time of year when they are feeding their young in the nest.

How to identify Dame’s Rocket:

Michigan Audubon describes Dame’s Rocket as having simple leaves that are long and lance-shaped, and feel downy. The stem also has rough hairs on it. Its flowers are purple, white, or pink in color and have four petals. 

Dame’s rocket flowers are somewhat similar in appearance to the native Phlox species. The two can be distinguished easily: Dame’s Rocket has four petals per flower and alternately arranged leaves, while phloxes have five petals per flower and opposite leaves.

For more identification assistance, visit the Midwest Invasive Information Network.

Removing Invasive Species in Rockford, MI

Next time you go for a walk, take along a paper bag and help secure the future of our native plants and the health of a balanced ecosystem. 

Garlic mustard and Dame’s rocket can be pulled by hand; please pull as close to the ground as possible to get as much of the root as possible – this works great if the soil is moist. Once you have pulled it, place the plant in a bag for safe disposal. Garlic Mustard and Dame’s Rocket flowers begin blooming in May and June and are very easy to spot. Now is the time to get out there and do some pulling!

Dame’s Rocket and Garlic Mustard should be disposed of in bags in the landfill, as both can set seed and reproduce if placed into compost piles or left on the ground after being pulled (if you pull before the plant flowers, disposal does not require special handling.)