University of Maryland Extension

Hairy bittercress

(More Lawn Weeds)

Hairy bittercress
Cardamine hirsuta

hairy bittercress
Hairy bittercress going to seed

Life cycle  

Primarily a winter annual. 

Growth habit

Basal rosette of pinnate leaves; 1-3 pairs of leaflets with
terminal, larger leaflet; tiny, 4-petaled white flowers in clusters at top of stems,
followed by slender, upright seed capsules.

hairy bittercress rosette
Young hairy bittercress
Photo: C. Carignan, HGIC

Reproduction 

Seed; when mature capsules pop explosively.

Conditions that favor growth

Shade and mowing lawn too short.

Management in Lawns

  • Cultural Practices 
    Maintain healthy, dense turf that can compete and prevent weed establishment.

  • Mechanical Management 
    Hand pulling or using an appropriate weeding tool are the primary means of mechanical weed control in lawns. This is a viable option at the beginning of an infestation and on young weeds. Hand pulling when the soil is moist makes the task easier. Weeds with tap roots like dandelions or have a basal rosette (leaves clustered close to the ground) like plantain or hairy bittercress are easier to pull than weeds such as Bermudagrass (wiregrass) or creeping Charlie (ground ivy) that spread with stolons or creeping stems that root along the ground.

  • Chemical Treatment in Lawns  
    Herbicides should be used as a last resort because of the potential risks to people, animals, and the environment. Read these precautions first. 
    preemergent applied in late summer/early fall can help prevent hairy bittercress from germinating, however, you will not be able to sow grass seed. Or spot treat actively growing weeds with a liquid, selective, postemergent, broadleaf weed killer in the spring before it goes to seed (photo at top of page). Look for a product with one or more of the following active ingredients: 
    2, 4-DMCPP (mecoprop), Dicamba* or Triclopyr.

    *Do not spray herbicides containing dicamba over the root zone of trees and shrubs. Roots can absorb the product possibly causing plant damage. Read the product label for precautions. 

  • Organic Lawn Herbicides

 

 

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