Crabgrass is a common weed in lawns this time of year particularly in sparse lawns. The blades of this warm-season, annual are flat, wide and lighter green than the desired turfgrass.
Crabgrass dies back after setting seed or the first frost leaving bare spots in the lawn. At that time cool-season grasses should begin to flourish and fill in the spaces. If you have crabgrass in your lawn now you can expect it again next year since it is so efficient at re-seeding.
Preventing crabgrass from establishing in the lawn is the best method of control.
Maintain a thick, healthy lawn to stop crabgrass seeds from germinating. Mow your lawn
no shorter than three-inches to help prevent sunlight from reaching the seeds on the soil
surface. Pre-emergence can be used in spring.
At this point in the season, it is too late for a crabgrass preventer. Manually removing
crabgrass plants is recommended for small areas and light infestations. There are some
herbicides that will kill crabgrass including: Ortho Weed-B-Gon Max + Crabgrass
Control, Fertilome Weed-Out with Crabgrass Control, Monterey Crab-ERad and
BioAdvanced Lawn Weed & Crabgrass Killer. Each of these contains quinclorac, which
is a crabgrass herbicide, as well as other active ingredients that control broadleaf
weeds. Quinclorac can also provide control for foxtail and certain other broadleaf weeds such as field bindweed, black medic and clover. Be sure to bag your clippings if you use
a crabgrass killer and don’t use them as mulch or compost.
