Nut Grass (Nutsedge) Control

“Nut grass” is the common name many people use for nutsedge (often Cyperus rotundus or Cyperus esculentus). It’s persistent because it spreads and stores energy underground in tubers (“nuts”), then pops back up when conditions are right.

Nut grass (nutsedge) plant
Nutsedge (“nut grass”) can regrow from underground tubers, so consistent timing matters.
Quick reality check: Glyphosate products (like Roundup®) can suppress nutsedge, but often don’t fully eliminate it—especially once plants are mature—because movement from leaves down to tubers can be limited. For best results, treatment timing and avoiding stress/cutting are key.

Step 1: Make conditions less “nutsedge-friendly”

Nutsedge loves moisture and often shows up where irrigation is frequent or drainage is poor. Before (or alongside) any spraying, reduce the “welcome mat”:

  • Fix overwatering / soggy zones. Improve irrigation uniformity and avoid keeping soil constantly wet.
  • Mow consistently in turf. Regular mowing can reduce competitiveness over time by forcing repeated regrowth.
  • Don’t till it through the yard. Disturbing soil can spread tubers into new areas.

Step 2: Physical suppression (beds and borders)

In planting beds, plastic mulches usually aren’t enough because nutsedge can poke through. A thick, nonwoven landscape fabric with mulch or gravel on top can suppress growth—but you’ll still need to remove any shoots that emerge.

Step 3: Smart herbicide strategy (don’t “double-blast” the same patch)

It’s common to hit nutsedge with multiple products in frustration, but that can be counterproductive if it removes the leaf surface too quickly. Herbicides that move (translocate) through the plant need enough healthy leaf area and active growth to reach underground tubers.

If you’re using a selective nutsedge herbicide (example: halosulfuron / SedgeHammer®)

  • Time it right: labels commonly direct application when nutsedge is actively growing and in an early leaf stage (often around the 3–8 leaf stage).
  • Don’t mow right before/after: for best results, avoid mowing for a short window before and after application (some labels specify 2 days).
  • Plan on follow-ups: nutsedge control is rarely one-and-done; repeat applications may be required, and labels limit how often you can apply per year.
  • Avoid drift/contact: selective sedge products can still injure desirable plants if sprayed over the top—use directed sprays where required.

If you’re using glyphosate (Roundup® type products)

  • Expect suppression, not instant eradication. Repeated applications are usually needed.
  • Spray when plants are young and actively growing (and not recently cut/mowed) so the product can move within the plant.
  • Be patient before “cleaning up.” Let the product work through the plant before removing treated foliage.
Important: Some halosulfuron labels allow tank-mixing with glyphosate in certain situations (like directed sprays in landscaped/fallow areas and turf renovation). If you do any mixing, always follow the most restrictive label directions for every product in the tank.

Common mistakes we see

  • Over-spraying. More is not better—too much can reduce performance and increase plant injury risk.
  • Spraying stressed plants. Heat/drought stress can reduce uptake and control.
  • Mowing/removing too soon. Cutting foliage immediately can reduce the herbicide’s ability to move downward.
  • Ignoring the wet spot. If irrigation/drainage isn’t addressed, nutsedge often returns.
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Note: Garden View is not a Licensed Pest Control Adviser. Always read and follow all label directions and local regulations. The information above is intended to help explain how nutsedge control works so you can make better decisions for your specific site.