Garlic Mustard: ID, Control, and Native Plant Replacements
Garlic mustard (Alliaria petiolata) is a non-native, rapidly spreading herbaceous plant found in woodland environments. Originally brought to the U.S. by early settlers for cooking, it forms dense colonies and readily spreads throughout shady areas, choking out native plants and tree seedlings. Seeds can remain viable in the soil for up to 7 years.
March-April:1st-year plants will consist of a
rosette with one-several scallop-edged dark green leaves, rising 1-6" above ground. They will remain green through the following spring.
April-May: 2nd year plants have a stalk that emerges from the rapidly growing rosette, with flowers forming late April-May. Leaves near top are triangular in shape. Plant is up to 4 feet tall with white flowers on the top. The only tall plant in the woodland with white flowers in May.
3. Summer: Seed capsules develop soon after flowering begins, and tops die when seeds mature.
1. Pulling: B
est to pull when soil is
moist after a rain. Start with new, small infestations first, and remove any 2
year plants before seeds fall. Start with least-infested areas first. Pull slowly from the base of the plant to keep from breaking stem off and make sure to remove entire taproot.
Plants pulled before flowers open:
Scatter to help dry, then burn. If left in piles or
moist conditions, they could still flower and produce seed. Can also leave in black plastic bags for growing season to break down.
Plants pulled once flowering has begun:
pulled plants should be bagged. Can also place all plants in a row with flower and seed heads going in one direction, then burn tops off with propane torch.
2. Cutting: Faster than pulling, avoids disturbing the soil, which can bring more seeds to the surface and encourage germination. Use a string trimmer and cut very close to ground level after stalks have elongated but before flowers have opened. May need multiple visits.
Disposal: Dry plants, place in large paper bags, burn. Leave bags open to promote drying. Do not compost.
Native Plant Replacements:
After removing garlic mustard, it is important to replace with either native plant seed or plugs. Depending on your situation, seeding with a native rye (such as Elymus canadensis) can be a cost-effective option to compete with garlic mustard in the early stages of restoration. If you have a small enough area, you can apply a layer of hardwood mulch and plant plugs such as wild geranium, wild ginger, columbine, and bottlebrush grass to spread relatively quickly.
Conservation@Home Feature: Meet the Dieckhoffs!
For the past 28 years, Terry and Pat Dieckhoff have lived in their Crystal Lake home in the Four Colonies subdivision. Their journey began with a simple desire....to mow less lawn. Terry, a retired teacher, began attending local WPPC yard walks and began using native plants. He was so encouraged by the beauty of the plants and wildlife that gradually the gardens expanded. They now have a native plant rain garden which has been so efficient that it has lessened the activity of their sump pump. They also use 5 rain barrels, recycle kitchen scraps with a compost pile, planted a bur oak for Pat's 50th birthday, and have 10 solar panels on their roof! They're not content with simply employing these practices on their own property. They want to encourage and educate others on actions they can take as well. Their property is part of local yard walks and they are certified through TLC's Conservation@Home program. They strategically placed their C@H sign to face a public park which adjoins their property, and speak with interested people who notice the sign. They are even featuring the C@H program at their church's Green Living Fair! Thanks to Terry and Pat for helping to spread the word about simple steps that anyone can take to make a difference.
Remember that you can also encourage others to participate in Conservation@Home. TLC can present to your neighborhood, community groups, etc. Call 815-337-9502 or email Sarah Michehl at
. Also, check out the updated Conservation@Home section of
, which now includes archived newsletters for you to easily access. And as the season progresses, please email us updated pictures of your environmental features!