Crabgrass lawn pre emigrant application
Look at our website for crabgrass control and Tips for Application. Look for products that do not contain fertilizer. http://extension.umd.edu/hgic/crabgrass
Apply prior to crabgrass germination which begins when soil temperatures are above 55° to 60°F for 7 to10 days (during and shortly after, forsythia bloom is a rough, but not consistently reliable, guide for application timing).
Granular crabgrass products are available to the homeowner. In general liquid products are used by lawn care companies.