Pre-emergent for Crabgrass
Grassman and our trained professionals apply a crabgrass pre-emergent at the optimum time in the spring, to ensure season-long prevention. (After this herbicide application, State of Connecticut guidelines recommend that you and your pets stay off the treated areas for 24 hours, after which time they are safe.)
The pre-emergent creates a barrier on top of the soil and kills seed sprouts that come in contact with this barrier. It's best not to thatch your lawn after the herbicide application, as doing so may break the barrier. Mowing your lawn a little higher also helps prevent these seeds from germinating, as crabgrass hates the challenge of a healthy, lush lawn. Thick turf also shades the crabgrass seeds so they can't sprout.
As the herbicide also kills grass seed, it's best to wait several months before applying new seed to your lawn. That's one reason why Grassman recommends applying the pre-emergent herbicide in the spring and seeding your lawn in the fall.