Ask a Master Gardener
I have a weed in my yard that I am told is nutsedge. How can I tell what it is for sure and then how do I get rid of it? GF
Essentially, we have two different nutsedges that are a problem in our area: yellow and purple nutsedge. Yellow is out now and purple emerges later. The challenge with both of these plants is that they are very aggressive, persistent, and hard to get rid of. Right now, you are probably looking at yellow nutsedge.
Yellow nutsedge can be positively identified in a couple of ways. First of all, feel the stalk. Nutsedges have a triangular stem that is easy to detect when you roll it between your fingers. For further confirmation, they produce yellow seedheads. If left alone, yellow nutsedge can grow to about 12 to 16 inches in height.
Nutsedge thrives in areas of your lawn that are moist whether that is from overwatering or leaky sprinklers. However, once they are established, they tolerate normal moisture in the soil.
Your first defense against nutsedge is to maintain a healthy lawn turf. Water appropriately and apply fertilizer at the proper rate and time of year. We have instructions on how to best water and fertilize your lawn on our website (www.tulsamastergardeners.org) under the Lawn and Garden Help Section/Turf.
Removing nutsedge mechanically, or in other words, pulling it out of the ground with your hands is problematic because the plant’s tubers are typically deep in the ground and tend to remain when pulling off the tops of the plants. You can dig down with a shovel or hand trowel to remove the entire plant including the tubers, but it’s difficult to be sure you get all the tubers since the spread underground. This strategy works best in the early spring before the plant has time to produce additional tubers.
If you have nutsedge in your vegetable garden, hand pulling is a viable strategy since it’s typically easier to dig in the garden than it is in your lawn. Just know that this will not be a one-and-done scenario. You will need to revisit this process every couple of weeks until you are sure you have removed all the tubers below the soil.
Unfortunately, these tubers can remain dormant in the soil for several years, only to pop up again when you think you are past the problem.
Nutsedge is sometimes called nutgrass because it resembles grass, but it is a different plant. All this to say, herbicides designed to control broad-leaf weeds or grasses will not be effective on nutsedge. To beat down the nutsedge you will need an herbicide designed specifically for the treatment of sedges. In this case a product call Sedgehammer (halosulfuron-methyl) works well on both yellow and purple nutsedge. Another product called Basagran (bentazon) works on yellow nutsedge. Follow the directions on the label for proper application. Good luck.
You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at firstname.lastname@example.org. Photo: Ohio State Weed Lab , The Ohio State University, Bugwood.org