Maintenance, mulching, and mowing are all expert-approved tools to help prevent fast-spreading hairy bittercress from taking over your lawn.
Hairy Bittercress: How to Identify and Get Rid of It
Published on Apr. 28, 2025
Hairy bittercress is a fast-spreading, cool-season weed that can quickly overtake your lawn if you don’t take the right precautions. Fortunately, with the right maintenance and preventative measures, you can keep this superabundant spreader from turning your grass from lush to lacking. I spoke with three turfgrass experts to get their tips for preventing and controlling hairy bittercress.
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What Is Hairy Bittercress?
Hairy bittercress (Cardamine hirsuta), or Lamb’s cress, flickweed, spring cress, or wood cress, is a low-growing, fast-spreading annual weed. Lawn care professional John D. Steiner explains that the plant belongs to the mustard family and thrives in cool, moist, shaded environments.
Hairy bittercress is native to Europe and Western Asia but has naturalized throughout much of North America. It grows readily in USDA hardiness zones 4 to 8. While it’s a winter weed that’s most prolific from late fall through early spring, it can linger year-round when conditions are ideal.
What Does Hairy Bittercress Look Like?
Are you unsure if it’s weedy, hairy bittercress emerging in your lawn? Steiner explains that this small, low-growing plant features pinnately compound leaves that divide into smaller, rounded or kidney-shaped leaflets.
“The plant produces small, white, four-petaled flowers, which develop into slender, elongated seed pods that burst open when mature, dispersing seeds explosively,” he says. Developing like a dandelion in a basal rosette, the leaves range from half an inch to one inch in size, and the flowers reach 3 to 9 inches tall.
Why Is Hairy Bittercress a Problem?
“Hairy Bittercress can be difficult to control due to its rapid lifecycle and high seed production,” Steiner says. “It completes its life cycle in just a few weeks, allowing multiple generations per year in favorable conditions.” He explains that even when conditions aren’t ideal, the seeds can remain viable for years in the soil, making eliminating these weeds from your lawn challenging.
Hairy bittercress seed pods, known as silique, contain as many as 30 seeds. When ejected from the pod, the seeds can land up to 16 feet away. This means you might treat one patch of lawn, only to discover these plants popping up on a separate patch later in the season. Plus, the seeds don’t have any dormancy requirements (a period of time when the seeds can’t germinate—even when conditions are right), and they germinate rapidly, reaching maturity and reseeding within five weeks.
The small, sticky seeds cling to containers and the underside of shoes, so you might not realize you’re bringing them home from a nursery or riverside walk, allowing them to spread into your yard sneakily.
How To Prevent Hairy Bittercress
Fortunately, there are some simple strategies you can employ to help prevent hairy bittercress from taking over your lawn or borders.
Promote a healthy lawn
A thick, healthy lawn not only looks good, it blocks out the light and space that hairy bittercress seeds need to germinate.
Plant genetics expert Matthew Koch recommends using a 3-in-1 grass seed, fertilizer and soil improver mix to help fix a patchy lawn. He also cautions against overwatering and suggests aerating your soil to break up compacted ground and improve drainage. “Since hairy bittercress prefers damp conditions, addressing excess moisture can make your lawn less hospitable to it,” he says.
Plant a dense ground cover
If you’re worried about hairy bittercress taking hold in non-lawn areas of your landscape, consider selecting a densely growing, low-maintenance ground cover, like thyme, that can choke out those unwanted weeds. Another option is to add a deep layer of coarse-textured mulch or some gravel.
Avoid spread from nursery plants and pots
Always wash out any nursery containers you plan to reuse to minimize the chance of stowaway sticky seeds spreading to your soil. Also, before planting any new greenhouse-propagated plants, check their soil for signs of germinating hairy bittercress sitting alongside them.
Minimize soil disturbance
Steiner recommends only digging or tilling your garden when absolutely necessary. “Disturbing the soil can bring buried seeds to the surface, triggering germination,” he says.
How To Get Rid of Hairy Bittercress
If your preventative strategies haven’t kept hairy bittercress at bay, here are some methods for getting rid of this weed.
Pre-emergence control
Applying a pre-emergence weed control product in late summer or early fall prevents those persistent seeds from germinating. “Several pre-products (dithiopyr, isoxaben, and oryzalin) have activity on hairy bittercress in turfgrass,” Professor and Extension Turfgrass Specialist Grady L. Miller says. Application instructions vary, so always carefully read the label, and don’t expect these products to work on emerged plants.
Post-emergence control
When you want to get rid of hairy bittercress that’s already established, you can apply selective or non-selective weed control products. “Post control can be achieved with several applications of mixtures of 2,4-D, carfentrazone, dicamba, MCPP, MCPA and/or sulfentrazone,” Miller says. “Other post options included atrazine/simazine (where appropriate/labeled), imazaquin, metribuzin, metsulfuron, triclopyr (alone or in combination with other broadleaf control products such as fluroxypyr or 2,4-D).”
It’s best to apply these products before the plant produces seeds, and always check the label for application instructions and to ensure it’s suitable for use on your lawn.
Pulling manually
Pulling these shallow-rooted weeds by hand or with a tool is a more time-consuming, physical removal method, but it’s a natural way to kill weeds and means you won’t risk damaging the surrounding lawn or ornamental species.
“Hand-pulling is most effective in moist soil when the roots can be easily extracted,” Steiner says. He also recommends doing this before plants flower and set seeds.
Regular mowing
Don’t panic if you’re not quick enough with chemical controls and there are too many hairy bittercress plants on your lawn to pull manually. “Regular mowing before the plant flowers prevents its seed pods from exploding and spreading seeds,” Koch says.
FAQ
Is hairy bittercress poisonous to animals?
Hairy bittercress is not poisonous to animals, so you don’t have to worry about your dog or pet rabbit nibbling on any untreated weeds appearing on your lawn. The leaves are actually edible, and their mild, peppery flavor makes them popular salad additions.
About the Experts
- Matthew Koch is the Director of Biotechnology, Genetics, and Seed at Scotts and has a PhD in plant genetics and breeding from Rutgers University.
- John D. Steiner is the Regional Manager for NaturaLawn of America. He is a licensed, seasoned lawn care professional with over 38 years of experience.
- Grady L. Miller, PhD, is a Professor and Extension Turfgrass Specialist in the Crop and Soil Sciences Department at North Carolina State University. His research activities are centered on cultivar evaluation, irrigation practices, turfgrass nutrition, and athletic field maintenance practices.
