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weed that pops seeds

The Weed of the Month series explores the ecology and history of the common wild plants that most gardeners consider weeds.

Thanks so much for informing me that this greenery can be eaten! I have pulled and tossed it from a landscaped bed on a warm winter day, but no more! I’m looking forward to a farmer’s sandwich now!

The Weed of the Month series explores the ecology and history of the common wild plants that most gardeners consider weeds.

Birds of Brooklyn: Red-Winged Blackbird

More: Learn to identify more weeds and find out more about each one by browsing the Weed of the Month archive.

While urban grazers will be most focused on the leaves, I think the seed capsules are the best part of hairy bittercress. Called siliques, they look like purplish-green toothpicks standing upright around the flower. As the seeds mature, the pods begin to coil tightly until—pop! A gentle touch or passing breeze triggers the pods to explode and send the seeds flying as far as three feet from the mother plant. This ballistic dispersal strategy, known as ballochory, is also employed by jewelweed and cranesbill.

As winter warms to spring, a favorite weed of foragers starts to emerge in rather cute clumps—it’s hairy bittercress! It has actually been lurking near the surface all winter, having germinated in the fall and waited out the cold temperatures before sending up flowers and seeds.

Hairy bittercress (Cardamine hirsuta) leafs out in a basal rosette, and like other members of the mustard family (Brassicaceae), its tender greens are edible. Don’t be fooled by the common name—its flavor is mild and peppery, not bitter. Though the flowers can be tough to chew, the tender leaves are suitable for a chic microgreens salad and have tons of vitamin C, calcium, magnesium, beta-carotene, and antioxidants.

Severe infestations of hairy bittercress weed will require chemical treatment. Herbicides applied post emergence need to have two different active ingredients. The ingredients must be 2-4 D, triclopyr, clopyralid, dicamba, or MCPP. These are found in broadleaf herbicide preparations known as two, three, or four-way treatments.

Prevent invasions into turf areas by encouraging good grass growth. The weeds easily infest thin or patchy areas. Apply several inches (8 cm.) of mulch around landscape plants to help prevent seeds from getting a foothold in your soil.

As temperatures get warmer, the plant will die naturally without having reproduced. That means fewer weeds the following season.

Cultural Control for Hairy Bittercress

Pulling out hairy bittercress weed usually leaves the root behind. The plant will re-sprout from healthy weeds and the problem persists. You can, however, use a long slim weeding tool to dig down and around the taproot and get all the plant material out of the ground.

This pesky weed is small enough to hide among your landscape plants. Its extensive seed expulsion means that just one or two weeds can spread quickly through the garden in spring. Early control for hairy bittergrass is essential to protect the rest of the landscape from an infestation.

Late winter and spring signal growth of all plants, but especially weeds. Annual weed seeds overwinter and then burst into growth towards the end of the season. Hairy bittercress weed is no exception. What is hairy bittercress? The plant is an annual weed, which is one of the earliest to sprout and form seeds. Control for hairy bittercress starts early in the season, before flowers turn to seed and get a chance to spread.

Hairy bittercress weed (Cardamine hirsuta) is an annual spring or winter pest. The plant springs from a basal rosette and bears 3 to 9 inch (8-23 cm.) long stems. The leaves are alternate and slightly scalloped with the largest at the base of the plant. Tiny white flowers develop at the ends of the stems and then turn into long seedpods. These pods split open explosively when ripe and fling seeds out into the environment.