Roundup for Lawns Crabgrass Destroyer will get rid of crabgrass and other grassy weeds from your Northern lawn. Simply use the attached Extended Comfort Wand to apply to actively-growing weeds. Each bottle treats 400 sq. ft. and the weeds will turn white 4-7 days after application! That temporary whitening lets you know that Roundup for Lawns Crabgrass Destroyer1 is working. This season kill the toughest crabgrasses down to the root, without harming your lawn.Features Kills the toughest crabgrass and grassy weeds without harming lawns (when used as directed) Designed for use on Northern lawns: Kentucky bluegrass, fine fescue, perennial rye grass and tall fescue Weeds will turn white 4-7 days after application, white means it's working Apply any time before seeding, including day of seedingSpecifications Size: 1 gal