How To Kill Crabgrass Completely.

Question

overrun with crabgrass in lawn, gravel and planting beds. sprayed roundup and crossbow then tilled and raked out all the roots i could find. it is back so how do i get rid of it for good?

Answer 1

Crossbow does not list crabgrass as a weed it kills. It is more for broadleaf weeds and poison ivy. Roundup kills grass and everything so I hope you only used it in gravel.
Use a product specifically labeled for crabgrass and other grassy weeds. You can use a preemergent in spring before the crabgrass germinates to prevent its growth. Then if it still shows up, you can use the postemergent specifically for crabgrass.