It’s a Weed, It’s a Grass, No It’s a Sedge!

I know you have seen them. They hibernate in the winter, but by late April they have started to pop up in your lawn. You mow the lawn and for the most part they have disappeared, but by the next afternoon there they are again sticking up above your lawn. Many call these grass-like weeds nutgrass, but actually they are in the sedge family.

The sedge family will have thicker leaves that come in sets of three with triangular stems which is unlike the grass family that has flat or oval stems. In the Central Valley we are blessed with two main types; yellow and purple nutsedge. The color referenced in the name refers to the color of the flower head with yellow ranging from yellow to light brown and purple having a reddish tinge to it. Hopefully you are mowing weekly or as needed and never see the formation of a seed head.

Yellow Nutsedge

Really, I look at the leaves and the underground nutlets to help me determine which one I am dealing with along with my nose and taste buds. Yellow nutsedge has a more slender and lighter green leaf than purple. It tends to grow taller as well. Underground tubers or nutlets form on the terminal end of the rootlets and are round. They are tasty and edible, too and much better if the dirt is washed off first. Purple nutsedge on the other hand has a denser, shinier, thicker, and more blunt leaf. Its underground tubers are scaly and can form in chains like Christmas lights. The soil around them has a distinct smell and the nutlets are bitter tasting. The nutlets can get much larger than the yellow nutsedge at maturity. 

Purple Nutsedge

The key to control is by managing the development of further nutlets. A healthy nutsedge plant will be collecting the sunshine and nutrients to expand both above ground parts and storage of carbohydrates in the formation of tubers. The goal therefore is to disrupt the happy leaf factory. Years ago, Kern County Farm advisor Harold Kempen showed that regular hand pulling of the plants could reduce populations by 60% in the first year and close to 80% or so by year two. Obviously pulling helps, but that is not very practical. There are several selective herbicides that will “hide” the above ground parts for 4-6 weeks thus slowing down the tuber formation and further expansion. I have not seen any silver bullets that fully eliminate nutsedge populations in 1 or 2 sprays, unfortunately. Persistence is the key to reduction and eventual elimination.

Finally, I would advise not over watering the lawn or flowerbeds as this favors expansion as well. Once established, they will do just fine under normal watering practices. If you would like to know more about nutsedge and proper control measures call Weed Man at 266-1624 or visit us at Fresno.WeedManUSA.com.