Here is pic of new crabgrass in a highly crabgrass prone area, which had a bad problem last year. May 9th. Lawn has not been treated. Michigan. We have had about 500 Growing Degree Days. Soil temp about 60. Max air temp so far about 82. Of course you can see dead skeletons of last year's crabgrass. And a few other weeds. Truck is broke. Online today.