Lawn Guardian

How to Get Rid of Hairy Bittercress

Cardamine hirsuta

broadleaf weedUSDA zones 3–9Active: spring, winter

Winter annual that germinates in fall and flowers very early in spring. Produces explosive seed pods that scatter seeds several feet.

How to identify it

Rosette of compound leaves with small rounded leaflets; tiny white 4-petaled flowers; narrow upright seed pods that pop open when touched.

Treatment options

Cultural (prevention): Hand pulling before seed set

Pull before explosive seed pods form. The pods can launch seeds several feet.

When: Pull in late winter/very early spring before pods mature

Organic: Dense turf in fall

Fall overseeding prevents germination spaces for this winter annual.

When: Overseed in early fall

Chemical: Broadleaf herbicide (2,4-D)

Post-emergent broadleaf herbicide controls emerged plants.

When: Apply in fall or early spring when actively growing

Active ingredient: 2,4-D — e.g. Trimec

Chemical: Pre-emergent (isoxaben)

Fall-applied pre-emergent prevents germination.

When: Apply in early fall before seeds germinate

Active ingredient: Isoxaben — e.g. Gallery

Grass safety: always match herbicides to your grass species — products safe on Kentucky bluegrass can kill St. Augustine or centipede. Lawn Guardian checks this automatically against your lawn profile.

Stop hairy bittercress at the right moment, automatically

Lawn Guardian turns this guidance into a schedule timed to your USDA zone and this week's actual weather — and adapts every time you log what you've done.

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Related weeds

Sources: Purdue University Turfgrass Science: Use Growing Degree Days to Better Time Your Applications · University of Missouri Extension: Cool-Season Grasses: Lawn Maintenance Calendar · University of Minnesota Extension: Pre-emergent Herbicides for Crabgrass Control in Lawns