War on Weeds: Crabgrass


Richard Old

This weed may invade your land. Be ready to oppose it.

The Enemy: Crabgrass (Digitaria sanguinalis L.)

Strategy: This summer annual has also been called “goose foot grass,” as the inflorescence is made up of three to five long spikelets that resemble the track of a goose. It often gets confused with Quackgrass, which is everywhere. This weed normally lies flat on the ground with purple-tinged, flat, hairy leaves. It is been found in eastern Idaho on a small scale for at least 30 years.

Attack: Crabgrass is aggressive at invading establishing lawns. It gets it foot into a lawn in the outer areas near sidewalks and driveways where there is usually disturbed soil. It invades in early summer and is the first to brown-out in the fall, after the first frost. As it grows flat or prostrate, it covers up desirable grass and slowly takes it over. Seeds can last three to four years in the soil.

Defense: Clean the dirt off your shoes before you leave an infested area. Hand pulling is an option, but difficult due to the intensity of established patches. Pre-emergent herbicides are the best plan of action. If you suspect an invasion, have the plant properly identified. In most cases, you may want to call in a professional lawn care service to have the property sprayed. Products such as Barricade and Dimension are available in large quantities to private landowners or they can also be found blended in with a fertilizer, which is available at most nurseries. These products can be applied in late fall or early spring. The key is to get these products in the soil prior to the germination of the weed, thus very early in the spring.

To learn more, call Bonneville County Weed Superintendent Jeffrey Pettingill at 529-1397 or email weeds@co.bonneville.id.us.