A dense healthy lawn is the best defense against crabgrass and other troublesome weeds. In gardens, mulch often prevents crabgrass problems.

Lifecycle

Crabgrass is one of the most invasive annual grasses in lawns and gardens. It germinates from seed in spring, grows and flowers in summer. Then it produces seed and dies after a killing frost in fall. The crabgrass seeds wait to germinate in early spring when the forsythia blooms.

Appearance

Crabgrass is a bunch-type grass with erect stems and pale green leaves about 1/4 inch wide that taper to a point. Small greenish flowers form along 3 to 10 finger-like branches at the top of the stem.

Lawn and Garden Locations

The most likely places to find crabgrass are sunny areas with thin or closely mown turf, heavy traffic areas or spots along the driveway where soil has been disturbed. Crabgrass also invades flower and vegetable gardens where soil has been tilled or raked.

The Need for Control

Crabgrass sneaks into areas unnoticed in spring but becomes an eyesore during summer, fall and winter. It stands out in a vigorous lawn due to its low, bunch-type growth habit, light green color and rate of growth. Its finger-like seed branches also attract attention in summer. Most noticeable in fall, crabgrass turns brown after the first hard frost, leaving brown patches throughout a lawn.

Control Strategy

Control is very simple. Timing is critical. In early spring when crabgrass seeds are just waiting to germinate in warm, moist soil (usually when forsythia is in bloom), apply a pre-emergent crabgrass control such as Agway Greenlawn Fertilizer Plus Crabgrass Preventer or Agway Greenlawn Crabgrass Control.