Over the past seven years of gardening at the San Carlos Community Garden, I’ve learned a lot about plants – unfortunately, that includes weeds.

One of them that I’ve become quite familiar with is nutsedge (Cyperus rotundus, also known as coco-grass, Java grass, nut grass, purple nut sedge or purple nutsedge, red nut sedge, Khmer kravanh chruk). It’s native to Africa, southern and central Europe and Southern Asia.

When I started gardening in the large display garden known as “the Patch” which is where we plant pumpkins and squash, flower bulbs among other things, I quickly learned that the soil needed more organic material because it was very compacted. I became aware of this when each winter there would be an onslaught of nutsedge as fall turned to winter. Suddenly these same long pointy grass-like weed would send up long stems with teeny tiny yellow seeds that looked like grass seeds. (There is also a purple nutsedge that has purple seed heads.) It can also appear within lawns.

Farmers generally despise this weed and as I had pretty much become a farmer with numerous raised beds that I leased, I determined to join the anti-nutsedge team but come up with an organic solution.

After some research on how to counter this weed organically, I applied what I’d learned.

As a result, I have nearly banished the nutsedge from our large approximately 10’x20’ Patch. It still comes up here or there, but I have learned it’s methods and this has really helped. A few teeny shoots may spring up particularly in summer and early fall, but they get removed within a day or two.

The solution—understand how nutsedge grows

When it’s very young, it just looks like a tall rangy grass blade. But when you dig it out, you quickly see that its base has numerous white root hairs and you’ve got to remove all of those. To do this, you must dig it out. Avoid pulling it out, because you will still have the tuber(s) down there to send up more nutgrass.

With time, the roots soon become large underground networks of tuberous masses of rhizomes known as nuts and can grow to up to 4’ deep. The nutlets are about .4-.8” long, kind of succulent at first and then with time they become brown-black.

Get to it earlier when you first spot it and it’s much easier to dig out. When you look at it from above ground top its green spikes form a triangle. Just pulling it does not get out all of the roots or the tubers. The weed tends to spread where the soil is compacted and hard, but also in areas that get a lot of water. You must dig down deep (like 10” deep or more) to reach the nuts and remove them and the longer you wait the deeper the network spreads.

How to get rid of nutsedge

Using a large shovel, dig down to remove any roots or nutlets, then over time continue to add a lot of garden compost or mulch to aerate your soil. These are the best ways to counter this pesky weed.

Also, do not let it set seedheads in late autumn and early winter or you are asking for it. (Seedheads appear about 7-8 weeks after initial shoots emerge.) Dig out any plants with seed heads the minute you spot them. Using green manures and cover to make your soil better like planting fava beans in the fall or sweet potatoes earlier in the year also will improve the tilth of your soil and make it far less of a problem. Energy reserves in tubers allows nutsedge to survive various light, water and repeated removal.

But I’ve found the best way to abate this weed is to make your soil rich loose, and full of compost.

Editor’s note: This article was written by Leslie Nelson, a gardener and board member with San Carlos Community Garden.