When is the best time to apply a preemergence herbicide for crabgrass control in the lawn?
A. Crabgrass usually starts to germinate when soil temperatures warm up to 50°-55°, which is usually around March 1st. Weed germination continues throughout spring, summer, and fall until soil temperatures start to cool down. Crabgrass is easy to control with preemergence herbicides but difficult to control with postemergence herbicides. For preemergence herbicides to be most effective it is best to apply them about three weeks before crabgrass germinates or between Super Bowl Sunday and Valentines Day. All garden centers have a big selection of preemergence products for crabgrass.
