Nuts about Nutgrass

Now just to be clear, that’s not nuts as in ‘in love’, that’s nuts as in ‘going slowly insane’.

In case you don’t know, nutgrass (Cyperus rotundus) is a grass-like weed which will appear anywhere. Lawns, garden beds, garden beds mulched with six layers of cardboard and a truck load of woodchips... (Ok no-one probably mulches their garden with six layers of cardboard. But if you did, nutgrass would still push through!)

Handily I have my own little nutgrass infestation that I haven’t dealt with so I had a weed photoshoot. Quite artistic I think?

Nutgrass is a beautiful shade of green and its tufts of thin flat leaves grow around 15-30cm tall. It spreads through rhizomes that zip along under the soil surface, but, connected to those rhizomes are little energy-storing ‘nuts’ or tubers which can be buried as deep as 30cm, sometimes more. These tubers break off easily, so that no matter how much you try to pull it up, there is always more to come.

Despite its common name, nutgrass is not technically a grass, it’s a sedge - an entirely different family. You might be thinking, ‘so what? I just want it gone!’. Well, as much as I am not a big advocate of poison, the fact that it’s not a grass is quite handy. There are special ‘sedge only’ selective poisons that only kill sedges. You can spray them all over your lawn, and liriope borders and they’ll only kill the nutgrass! (and Mullumbimby couch, Cyperus brevifolius, because that’s also a sedge!) Magic huh? Granted, magic that doesn’t come cheap, but still.

“Sedges have edges, rushes are round, grasses have nodes, right down to the ground”. Not my rhyme, but it’s good! See how the cross section of nutgrass is triangular? - Sedges have edges!

Before you reach for the poison though, nutgrass loves the heat and thrives in areas with poor drainage. So if your garden beds and lawns are overrun with nutgrass, it’s a sign that you could do a bit to improve your soil. Aerate your lawn, and add organics to your garden beds to keep that pesty weed from flourishing.

Alternatively, dig, dig, dig and harvest your tubers. Although reputedly not as tasty as it’s cousin yellow nutgrass, (Cyperus esculentus), it is apparently edible and medicinal. I think I’ll pass on that though and store my ‘harvest’ in the rubbish bin…