What I found shocked me! The data show that soil temperatures reached 52 degrees F. on Feb. 24 in 2000, Feb. 25 in 2001, Mar. 14 in 2002 and Mar. 4 in 2003. My timing advice has been wrong ! To get good crabgrass control in Atlanta you should apply the pre-emergent on March 1, not March 15.Otherwise the seed will sprout beforehandâ¦.and most pre-emergent chemicals do not control crabgrass seedlings.hat I found shocked me! The data show that soil temperatures reached 52 degrees F. on Feb. 24 in 2000, Feb. 25 in 2001, Mar. 14 in 2002 and Mar. 4 in 2003. My timing advice has been wrong ! To get good crabgrass control in Atlanta you should apply the pre-emergent on March 1, not March 15.