You may have a type of grass growing in our flower beds that seems to grow more when you pull it up. Yellow nutsedge is a prolific weed and very difficult weed to control. Most think the weed is a type of grass, but it’s classified as a sedge. The blades are triangular shaped and grow very rapidly in hot, humid weather that we’ve experienced over the past few weeks.

Unfortunately, yellow nutsedge forms tubers (nuts) at the tips of the rhizomes. During the growing season, plants spread by rhizomes or underground stems producing “daughter plants.”
Yellow nutsedge begins forming tubers at the tips of the rhizomes maturing in late July to mid-August. Spot spraying with a systemic herbicide such as glyphosate (Roundup) will control the newly emerged nutsedge, however the sprouts below ground generally continue to emerge and continue to be a problem.

Many landscape maintenance professionals prefer to use a post emergence herbicide with the active ingredient Halosulfuron-methyl to control the weed. It’s often sold as Sedgehammer or other trade names in local garden shops and retail outlets.
Go to http://www.clemson.edu/extension/hgic/pests/weeds/hgic2312.html for more detailed information about the yellow and other sedges.

Darrell Blackwelder deblackw@ncsu.edu is the retired horticulture agent with the North Carolina Cooperative Extension Service in Rowan County.