Crabgrass is a pain in the grass.
And that’s a fact. Once crabgrass is established for a growing season is can be a pain to get control of.
There a number of ways to keep the crabgrass at bay for the season, let’s go over them.
Good grass beats (crab) bad grass-mow, trim, repeat. The number one defense against weeds in your lawn, including crabgrass is a well established, regularly mowed lawn to keep a thick full turf that keeps the weeds and unwanted grasses at bay. Tall, thick grass both shades and crowds out weeds and crabgrass not allowing them to take hold. Keep a regularly mowed lawn and don’t cut more than one third of the grass blades off at a time, and keep it above 3 inches. Also, since crabgrass tends to grow in dry, bare areas, don’t scalp your lawn! Same goes for edging/trimming – with our Wisconsin winters we do not recommend edging out a large gap near your concrete edges. This can and will fill and freeze through the harsh winter and not look great when that gap fills with crabgrass come summer. We recommend creating a nice looking edge where the turf meets the concrete with a trimmer over time and maintaining that once this looks nice and clean.
Keep that grass fed. To keep a well maintained turf that can crowd out crabgrass you want to be sure the soil has the proper amount of Nitrogen to help that grass grow. Here in Wisconsin, as a general rule, 3.5 lbs of Nitrogen per 1000 square feet, per season is recommended to keep a healthy green turf. Always be sure to follow label instructions, or call us to help out.
Get it before it gets you. Preemergent herbicide works to keep the crabgrass at bay. This is all about timing. This needs to be applied when the soil reaches a temperature of 50 degrees; before that crabgrass starts moving and grooving and trying to pop its evil heads up. Preemergent has proven to be the to be a great defense against crabgrass if applied at the right time. If the window is missed to apply preemergent crabgrass can be a pain. This handy calculator will give you the optimal time to put down preemergent based on the temperatures in your area for this year: http://www.gddtracker.net/
Pull it-Kill it. Hopefully you don’t make it this far down this list, but if you do have crabgrass established in your lawn it can be killed. Using a post emergent herbicide or pulling the grass does work. Depending on the level of establishment for the season though you may need to reseed these areas with the good stuff if necessary.