Apply the first round of crabgrass prevention in late March–early April.
- Because spring weather varies, use flowering as a cue for when to apply pre-emergent crabgrass control. Apply while forsythia is blooming or by the time that dogwoods are blooming (late March–early April), then apply a second round about 6 weeks later. Learn how to maximize the effectiveness of pre-emergent control.
- Cool-season lawns need to rest for the summer, so use a pre-emergent that does not contain fertilizers. Products containing dithiopyr also provide post-emergent control for young crabgrass.