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 1000 sq-ft and the weeds will turn white 4 to 7 days after application. That temporary whitening lets you know that Roundup for lawns crabgrass destroyer is working. This season kill the toughest crabgrasses down to the root, without harming your lawn.