How-To
Garlic Mustard: How to Pull It Right
Garlic mustard is one of the most aggressive invasive plants in Central Ohio's woodlands, and it thrives in the same cool, moist spring that wakes up our native wildflowers. The good news: if you time it right and pull correctly, you can actually get ahead of it. Here's what you need to know.
Identifying garlic mustard
Garlic mustard is a biennial, which means it lives two years. You'll see it in two very different forms depending on the season, and knowing the difference helps you spot it early.
First-year rosettes (fall through early spring)
In late fall and throughout winter and early spring, garlic mustard spends its first year as a low, circular cluster of leaves close to the ground, a rosette. The leaves are heart-shaped to rounded, with slightly scalloped edges, and they stay green even in winter. If you crush a leaf between your fingers, you'll smell garlic or mustard, a distinctive, bitter-sharp odor that's unmistakable once you know it. These rosettes are the easiest form to pull because they haven't flowered yet and the root system is still manageable. Look for them in moist, shaded spots along the Olentangy, Scioto, and their tributaries, and in woodland edges across the Columbus metro area.
Second-year flowering plants (spring)
In its second spring, garlic mustard bolts upward into a leafy stem one to three feet tall and produces small white four-petaled flowers arranged in a loose cluster at the top. The upper leaves narrow and become lance-shaped. By late spring and early summer, the flowers give way to long, thin seed pods. Once you see the flowers, it's already too late to avoid the seed. The plant will produce hundreds of seeds, all of which will rain down into the soil and germinate in future years.
When to pull: the spring window
Timing is everything with garlic mustard. The best window is spring, roughly from when the first rosettes begin to bolt through mid-May, before seed pods mature and split open. This timing works because soil is naturally moist from winter snowmelt and spring rain, which makes pulling easier and more likely to get the whole root.
First-year rosettes should ideally be pulled in their first fall or early spring, before they have any energy for flowering. If you miss them and they bolt, pull them before they set seed. Once you see mature, brown seed pods on the plant, the battle is essentially lost for that year. The seeds are viable and will disperse on their own or with disturbance. Focus your energy on plants that haven't flowered yet.
The reason spring matters so much is twofold. First, seeds remain dormant and viable in the soil for years, waking up in spring to germinate. Second, garlic mustard's whole aggressive advantage is that it flowers and sets seed before most of our native spring wildflowers and ephemeral wildflowers have even emerged or finished blooming. It's a race for light and resources, and garlic mustard wins if you let it.
How to pull garlic mustard correctly
The goal of pulling is to remove as much of the plant and root as possible, especially the root crown where new shoots can regrow. Here's the right way to do it.
Wait for moist soil. Pull after rain or when the ground is still damp from spring moisture. Wet soil is easier to work with and less likely to snap the root off below the soil surface. If soil is dry and hard, water the area the day before if you can.
Grab low and pull firmly. Get your grip as close to the base of the plant as possible, just above the soil line if you can. Use a steady, upward pull rather than a jerking motion. The goal is to extract the whole taproot, especially the crown, which sits at the soil surface and can send up new growth if left behind.
Check your work. Once you've pulled the plant, look at the root. A good pull will bring up a root that goes several inches deep. If the root snapped off and just the top came away, go back and dig out the remaining root stub with a small shovel or trowel. Small root pieces left in the soil can regenerate.
Do not leave pulled plants on the ground. Garlic mustard plants that are wilted or dying can still complete their reproductive cycle and set a few seeds. Even partly-mature seed pods may continue to develop. Remove the plant from the site immediately. Don't let it sit on the forest floor.
What to do with pulled plants
Here's where most people make a mistake: do not compost garlic mustard or leave it on site to decompose in a brush pile.
Bag the pulled plants in a sealed garbage bag and put them in the trash, even if they seem completely wilted. The reason is that garlic mustard seeds have very high dormancy and longevity. They can survive the moderate temperatures and moisture of a backyard compost pile, and if you use that compost in a garden or around trees, you've just spread the problem. Professional compost facilities that reach higher sustained temperatures might destroy seeds, but residential composting usually doesn't get hot enough for long enough.
If you've pulled a large area and have a lot of biomass, double-bagging helps ensure the material stays contained until trash collection. Never leave pulled plants in a pile at the edge of a woodland, where seeds can still mature and disperse, or where wind and water can carry them further downstream to new habitat.
Why this matters
Garlic mustard doesn't just crowd out wildflowers, it actively changes the soil against them. The plant releases chemical compounds from its roots that inhibit the germination and growth of native plants. But there's something even more subtle happening: garlic mustard interferes with mycorrhizal fungi, the fungal partners that live in the roots of native plants and trees and help them absorb water and nutrients. Without these fungal networks, native plants can't compete and often simply fail to thrive.
Spring wildflowers (trilliums, woodland phlox, bloodroot, trout lily) emerge in a narrow window when the forest canopy is still bare and sunlight reaches the floor. Garlic mustard flowers during that same window and wins the race. Over a few years, a patch of garlic mustard can turn a diverse woodland understory into something close to a monoculture. Instead of a floor of spring color in an Upper Scioto woodland, you get a wall of white flowers and, later, a barren stem-scape.
Pulling garlic mustard isn't the end of the story, without ongoing removal year after year, new plants will germinate from the seed bank already in the soil. But it's a necessary practice, especially in your local woods, parks, and the spaces where our native spring ephemeral flora still hangs on. Every plant you remove before it sets seed reduces future work and gives native species a fighting chance.
Frequently Asked Questions
When should I pull garlic mustard?
Late winter through mid-May is your window, with early spring (when soil is wet from snowmelt or rain) being ideal. Target first-year rosettes in fall or early spring, and any flowering plants before the seed pods mature and turn brown. Once seed pods are dry and brown, the seeds are viable and will disperse. After mid-May, focus your energy on plants that haven't flowered yet and plan for next year.
How do I get rid of garlic mustard for good?
One pulling session will not permanently eradicate garlic mustard from a site. Seeds in the soil will germinate in future years, sometimes for many years depending on the size of the seed bank. The realistic approach is annual pulling during the spring window, targeting plants before they flower. Over time, as you remove plants before seeding and the seed bank is exhausted, populations do decline. If the infestation is very large, prioritize the most biodiverse areas or highest-value habitat first.
Should I compost or bag pulled garlic mustard?
Bag and trash it. Garlic mustard seeds survive typical residential composting temperatures and can germinate if that compost is later spread on soil. Even a small fraction of seeds surviving in your compost pile can establish new populations. Sealed trash bags ensure the seeds leave the landscape entirely. This is the safest disposal method.
Getting started
If you've never pulled garlic mustard before, start small. Pick one shaded area along a stream or under trees where you know invasive plants are present, and pull for an hour or two. You'll quickly develop an eye for the rosettes and flowering plants. Once you know the plant well, you can expand to larger areas and organize group pulls with neighbors or a local stewardship group. Consider checking native alternatives for what should be growing in the spaces you're clearing, so you can appreciate the plants that will return as garlic mustard recedes.