What is the best time to apply pre-emergent herbicide to my lawn to control crabgrass, foxtail and annual broadleaf weeds?

The most common pre-emergent is crabgrass preventer; this is usually applied to the turf around April 15th – May 1st. Crabgrass germinates after soil temperature has reach 55 degrees for several days in a row, so if we keep having these cool days you could hold off a few days. You do need to make sure you have it on the turf before the crabgrass germinates, or it will not work.