LawnSuite guide: Nutgrass in lawns: why it keeps coming back
Use this LawnSuite guide to recognise the problem before deciding what to do. Nutgrass isn't a true grass. It's a sedge that spreads through chains of small underground tubers, which is why pulling the tops off rarely gets rid of it.
How to spot it
Nutgrass, also called nutsedge, is a perennial sedge with shiny, dark-green, grass-like leaves and compact seed heads. Underground it forms chains of small brown tubers.
When it shows up
It starts growing as temperatures rise in spring; its tubers generally won't sprout below about 20 °C.
Where it grows
It prefers open, sunny spots and doesn't do well in shade. It's a persistent weed of gardens and lawns, and each season it adds more small tubers underground.
Lawn care that helps
Dig out small patches only if you can remove the whole tuber chain as well as the tops: tubers left behind or broken off can regrow. Keep it out in the first place: tubers travel in soil, so be careful with soil, manure and potted plants you bring in.
If you use a product
Nutgrass is very hard to kill. If you use a herbicide, choose one whose label lists nutgrass and your turf type, and follow the label.
Keep reading
Sources: Australian government and university pages, summarised in our own words.
Not sure it's nutgrass?
Create a free LawnSuite account in your browser and photograph the patch. Photo diagnosis uses Google Gemini vision to identify the likely weed, pest or disease and shows a confidence score for each result, so you can match it to the signs on this page before you treat.