Weed Watch: How to Kill Nutsedge

| 3/2/2011 11:06:55 AM

Tags: weed control, weeds, nutsedge, garden weeds,

NutsedgeHow can I kill yellow nutsedge? I’ve tried landscape fabric, newspaper and various mulches without success, and the fire ants loved the mulches as much as the nutsedge. I even tried a sinful herbicide, and the nutsedge laughed it off. It’s not practical to dig up all the “nuts” (root nodules). What can I do? 

We are truly sorry to hear that your garden has become infested with yellow nutsedge (Cyperus esculentus), which compares in scope to a plague of locusts. In the course of a growing season, a single healthy nutsedge plant can produce 1,900 new plants and up to 7,000 nutlets on their roots! Originally from Europe and India, yellow nutsedge and the less cold-hardy but equally aggressive purple nutsedge (C. rotundus) are commonly listed as noxious weeds around the world. On the bright side, the nutlets produced by these amazingly prolific plants are edible. C. esculentus roots taste like coconut and can be eaten raw, boiled or roasted. However, even if you like the taste of nutsedge, you don’t want it to completely take over your garden, so it’s time to consider drastic measures.

You are correct about the futility of sifting through your soil to physically remove all the nutlets. Although most are found in the top 6 inches of soil, some may be lurking as many as 14 inches deep. You will never collect them all. The herbicide you tried didn’t work because, after one sprout died, a second one grew from the mother nutlet to replace it. Individual nutlets can resprout three times — maybe more — so an effective control strategy is to do everything you can to encourage the colony to sprout itself into exhaustion. This nutsedge cleanup will require taking the infested space out of production for a year, and weeding, hoeing or tilling it every three weeks (innocent-looking little nutsedge plants start producing nutlets in about a month). Weed scientists estimate that a nutsedge tuber uses up 60 percent of its energy reserves on its first sprout, and 20 percent for the second, so the stand should get weaker and weaker after each cultivation. By the time the weather turns cold and the weeds stop sprouting, your garden should be looking pretty clean.

When your soil gets out of rehab and you’re ready to plant crops again, use tight spacing to keep the soil as shady as possible, pull out or hoe any nutsedge sprouts the minute you spot them, and limit watering to only where you’re actually growing your crops. If you haven’t tried pine bark mulch, see whether you can slip it by your fire ants. In a study done in Hammond, La., pine bark mulch reduced nutsedge in flower beds by 75 percent. Good luck!

Above: If nutsedge shows up in your garden, remove it immediately! Photo by Sue Day. 

Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on .

3/24/2015 3:00:15 AM

Also a big problem in Australia, called Nut Grass down under. Thanks for the great article, I wrote one on my blog too - http://www.reddiamondgardencare.com.au Have a great day RD

kimit muston
12/2/2012 3:04:22 PM

Uccch. They sprouted last year (for the first time in 6 years of that bed being totally under my control) in one of the many beds I have on my front lawn (flowers over grass, I always say) and I did NOTHING to get rid of them as I didn't know what they were. Blammo. Now they're popping up in another of the many beds (this one smaller, but I transplanted chocolate ajuga from the backyard, which had quickly filled the bed, along with hostas, a lovely light green trailing sedum and some stonecrop); I'm yanking them out as soon as I see their disingenuously innocent looking green spprouts but my back can take just so much stooping and yanking before I am flat on the floor for 3 days with pretty severe back pain. Uccch.

ruth parmentier
6/9/2011 9:30:06 AM

Try adding a couple drops per/gal of Dawn dish soap to the solution to help put a end the nutsedge nightmare.

barbara pleasant_3
6/3/2011 7:24:45 AM

Sac, bamboo laughs at linoleum. I have actually heard of people who have installed vertical underground concrete barriers to restrain running varieties. Instead of gardening right next to your bamboo, allow a mowing strip between the bamboo and your beds. You will still have shoots to pull out, but a mowed area will give you a fair chance at domination and reduce shade from the tall bamboo. Good luck!

6/2/2011 5:37:25 PM

The most invasive weed I have dealt with here in Arizona is bermuda grass. OK for a lawn grass or pasture grass, but awful in the garden. Rototilling it does not kill it, because all those chopped up roots are potential new grass plants. So onetime when I bought a house with a bermuda back yard, selected an area where I wanted the garden, rototilled it up really well, THEN I fenced it off from the rest of the lawn, and put about 3 hens in it. They very happily scratched through the soft dirt, eating all the bermuda grass stems and roots. After a few months there, the garden space was very bermuda free. According to a recent MEN post, the same can be done with pigs, only they act as their own rototiller. Good Luck. Ron

6/1/2011 11:24:44 AM

Hold on! I've found a guaranteed cure for every/all weeds/bugs/fungus, etc. I found it in a oldtime gardeners' book and it works! SOLARIZE! Cut down all vegetation to ground level. Cover area with CLEAR plastic sheeting. (heavy duty). Bury edges of plastic or hold down with garden staples/logs/rocks, etc. (buried edges are best.) Leave on for 2 or 3 summer months. (or all summer) I did this to my big veggie garden 4 yrs ago after getting hit with Squash virus and some kind of millipedes/worms that were eating my seed. Plus pursalane weed and dandelions. IT WORKED! Meanwhile, that year, I did some container gardening to get by. The sun heats the soil VERY hot and kills everything. The next year, I had to add soil amendments to bring back the good stuff to the "dead" soil. I happy to say, I'm back in business! Without chemicals!

6/1/2011 10:30:16 AM

I have a problem with bamboo. We cleared the garden area and removed most of the roots, too. We built raised beds and laid linoleum under the beds to keep the bamboo at bay. All was well for the first couple of weeks, but now the bamboo is popping up everywhere, including finding ways around the linoleum and through the raised beds. We keep pulling and the stalks seem to die in that place, but crop up elsewhere. Any suggestions?

c koehn
6/1/2011 9:30:13 AM

Three cheers for this information...It totally agrees with my experience. Only by FREQUENT cultivation can there be any measure of control. But if you get caught sleeping...NUTSEDGE WILL BE BACK!

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