- Nutsedge is a sedge, not a grass. Roll the stem in your fingers: it's triangular.
- It spreads by underground tubers. Pulling it usually leaves tubers behind to resprout.
- Standard crabgrass pre-emergents generally don't control it.
- Wet soil favors it, so fixing drainage is part of the cure.
By early summer, a lot of lawns across Jackson and Banks counties grow a crop of bright, yellow-green blades that stand above the rest of the turf a day or two after mowing. Homeowners call it "that weird grass." It's yellow nutsedge, and it's one of the most persistent weeds we treat.
How to identify it
An old saying helps: sedges have edges. Pinch a nutsedge stem and roll it between your fingers. It feels triangular, not round or flat like a grass blade. The leaves are glossy, lighter green than most lawn grasses, and grow noticeably faster. In late summer you may see yellowish-brown seed heads.
Purple nutsedge and kyllinga are close relatives with similar habits. Treatment approaches are similar, though some species are tougher than others.
Why pulling makes it worse
Nutsedge spreads mainly through small underground tubers, the "nuts" in its name, connected by underground stems. When you pull a plant, the stem usually snaps above the tuber. The tuber stays in the soil and sends up new shoots, and disturbed tubers can sprout as well. Each plant can produce many tubers over a season, so a few plants become a patch fairly quickly.
Why mowing doesn't help
Because nutsedge grows faster than turf, it's always the tallest thing in the lawn a few days after mowing. Mowing lower doesn't hurt it. Scalping your lawn to keep up actually weakens the grass and gives nutsedge more room.
Why your pre-emergent missed it
Most pre-emergents used for crabgrass target seeds. Nutsedge comes up mainly from tubers, which those products generally don't stop. That's why a lawn can be nearly free of crabgrass and still full of nutsedge. Read more about what pre-emergent does and doesn't do.
Wet soil is the root cause
Nutsedge thrives in soil that stays moist. Low spots, areas near downspouts, soggy patches over compacted clay, and lawns that are watered too often all invite it. When we see a heavy nutsedge patch, we look for a drainage problem nearby, and we usually find one. Correcting that is often the difference between controlling nutsedge for a season and getting rid of it. Our guide to clay soil and standing water explains the common causes.
What actually controls it
Selective post-emergent herbicides labeled for sedges can control nutsedge without harming most lawn grasses. A few points make the difference between success and frustration:
- Treat young, actively growing plants. Early summer, before the plant has built up many tubers, gives the best results.
- Expect repeat applications. One treatment rarely gets every tuber. A follow-up several weeks later is normal.
- Don't mow right before or after treatment. The plant needs leaf surface to absorb the product.
- Match the product to the turf. Labels differ for Bermuda, Zoysia, Centipede, and Fescue.
Herbicides must be applied according to the label, and in Georgia, applying them for hire requires a state license. Our applicators are licensed and choose products based on your grass type.
A realistic timeline
Heavy infestations usually take a full season, sometimes two, to bring under control, because tubers in the soil keep sprouting. Combined with better drainage and thicker turf, the patches shrink every year. If nutsedge has taken over a large area, it's worth an on-site look to see whether treatment alone is enough or whether drainage and renovation should come first.