Hairy Bittercress - Weed of the Week

Taming the Ubiquitous Hairy Bittercress

Warmer temps and spring-like weather are welcomed by many. But, with this nice weather comes lawn/garden weeds, and they can take off swiftly, providing a limited window of opportunity for homeowners to get them under control. Once such weed is hairy bittercress. Common in West Virginia lawns and gardens, this weed is a winter annual that grows predominantly in spring but is capable of germinating and growing year-round under suitable environmental conditions.

Benefits of Hairy Bittercress

Although many homeowners may view the hair bittercress a pest, the plant is edible and has other good attributes. Hairy bittercress is rich in antioxidants and some people use it as substitute for parsley when cooking. Hairy bittercress is a member of the mustard family and spreads by seeds that are dispersed as the pods burst open explosively after maturing. The seeds usually germinate in late summer or early fall and seedlings remain dormant until the weather warms up in early spring and they grow quickly, producing white flowers.

Controls for Hairy Bittercress

These short-lived plants have shallow root systems that readily respond to hand-weeding or cultivation. Applying a good mulch prior to germination of hairy bittercress is recommended in flower beds to proactively manage the weed. Actively growing weeds can be easily hand-weeded by taking advantage of their shallow root system. If you are finding hairy bittercress on your lawn, chemical control is an option that involves applying a preemergence herbicide in late summer before the seeds germinate or applying postemergence herbicide to young and actively growing weeds in lawns. Keep in mind that applying most herbicides applied over top may cause injury to ornamentals. Preemergence herbicides effective on lawns include isoxaben (Gallery) and oxadiazon (Ronstar) and those in flowerbeds include oryzalin (Surflan), isoxaben + trifluralin (Snapshot). Postemergence herbicides to control this weed in lawns include a combination of triclopyr (Turflon), carfentrazone + 2,4-D (Speedzone). If using a preemergence herbicide, especially in fall, it may be a good idea to include a postemergence herbicide such as triclopyr or 2, 4-D to control seedlings.

You also will find these tips useful in addressing other winter annuals such as purple deadnettle, henbit, common chickweed and mousear chickweed. Be sure to read all of the labels carefully before applying an herbicide to ensure that it is safe on the plant material used for and effective for the weed to be controlled. Specialty herbicides, especially certain pre-emergence herbicides, may not be readily available in retail stores. Once you have treated the area, you can reseed the grass to prevent other weeds, such as crabgrass, from establishing in that area.

Recommendations for the use of agricultural chemicals are included as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services does not imply endorsement by West Virginia University Extension nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your county Cooperative Extension agent.