When is the best time to apply pre-emergent weed control which includes crabgrass preventer? Perhaps the best indicator is soil temperature. Soil temperatures need to be at least 50 degrees F. So waiting for soil temperatures above that point may be a little too late and applying below 50 degrees could be a waste. Crabgrass seed begins to germinate when spring soil temperatures are above 50 degrees F. Even timing the pre-emergent application correctly will […]