Turfmate field notes · Weeds

Nutgrass

Cyperus rotundus

A sedge with triangular stems and persistent underground tubers.

Nutgrass plant and seed heads.
Nutgrass plant and seed heads.
Photo: Rickjpelleg · source · CC BY 2.5. Displayed at reduced size; card crops fit the layout.

What to look for

  • Upright growth can stand above the surrounding lawn.
  • Stems are triangular rather than round.
  • Underground tubers help explain repeated regrowth.

Confirm it before you treat it

Separate nutgrass from onion weed, grass seedlings and other sedges. Include the stem, leaf arrangement and a carefully lifted plant in your photographs. A product that controls clover is not automatically a sedge treatment.

What to do next

  1. Act while the infestation is small and avoid spreading tubers in soil.
  2. If digging out plants, remove the underground structures thoroughly; simply pulling off leaves is unlikely to solve it.
  3. Confirm lawn establishment and condition before selecting a labelled sedge treatment.
Seasonal watch

Conditions matter more than dates.

Active sedge growth is the useful treatment trigger. The visible shoots are only part of the infestation.

Monitor during warmer growth periods and after site disturbance. Mild northern or irrigated sites can remain active longer.

Explore your region & month ↗

Why does it come back after I pull it?

Underground tubers can remain and regrow. Identification and a plan for the underground infestation matter as much as removing the leaves.

Keep investigating

Similar problems. Different solutions.

Reviewed 10 October 2026 · Turfmate. Seasonal windows are indicative planning guidance, not measured outbreak or prevalence data.

Technical sources & image credits

Photos support identification and may have been taken outside Australia. Appearance varies with species, mowing and conditions. A Turfmate product link does not imply endorsement by a photographer or source.