Pre-Emergent Crab Grass Application for 2019

Asked March 17, 2019, 6:49 AM EDT

This is all about the window of opportunity. I live in Carroll County. When do you suggest applying pre-emergent for crab grass control this season? Is Forsythia blooming still a good rule of thumb?

Carroll County Maryland

1 Response

You still have time to apply a crabgrass preemergent. In general, Crabgrass seeds germinate when soil temperatures average 55-60 degrees F. for seven days to ten days. There are different microclimates in your yard and soil temperatures may be different in areas such as south-facing areas, near sidewalks, etc. If you do not have a soil thermometer (and most people don't!), during and shortly after, forsythia bloom is a rough guide for application timing. Here is more information on crabgrass, preemergents, and tips for application

University research has shown that proper mowing (3-4 inches), fertilizing, and repairing bare spots will also help to prevent crabgrass.