This Grassy weed Is Not Technically a Grass; It's a Sedge and Is Very Difficult to Control
Mow High to Help Control Nutsedge
Depending on your turf type and latitude, you can help control nutsedge or nutgrass by changing the way you mow. Mowing your lawn at the proper height, which in most cases is one of the 2 highest settings on your mower, lets the grass crowd out nutsedge and other weeds. Mowing short stimulates nutsedge.
You can help prevent nutsedge by regularly feeding your lawn with Scotts® Turf Builder® Lawn Food. A healthy, maintained lawn is the first defense against nutsedge. A well-fed lawn grows thick and is better able to crowd out weeds. If you're seeding a new lawn, you can prevent yellow nutsedge for up to 6 weeks by applying Scotts® Turf Builder® Starter® Food for New Grass Plus Weed Preventer.