How to Kill Nutsedge in Your Lawn
In our business, we print out tickets for our techs to go out and treat lawns. If you’re a customer of ours (or of any lawn care company’s) you know this, because we leave the invoice half on your door. But what you don’t see is the other half, which tells the lawn tech everything he needs to know before he does your lawn – what kind of grass you have, whether we treat your whole yard or just the front, how big your lawn is, etc.
When we get the guy’s half of the ticket back in the office, we post what was done in the computer. Many times, the guys make their own notes which we also put in the computer, such as “shut gate – bunny in back” or “4 Great Danes!!!” or “gate code - 1234” or anything they deem important enough to know in case someone else does the lawn while they’re on vacation.
Occasionally, I’ll run across a ticket that says “KILL THE NUTSEDGE!!!” It’s never “kill the nutsedge.” No, it’s always “KILL THE NUTSEDGE!!!”
They are so vehement about nutsedge, because it’s the weed most likely to drive a homeowner nuts (no pun intended, really…)
Nutsedge is a paler green than bermuda grass and grows so quickly that one or two days after you mow, it’s up higher than your bermuda. Looks terrible! Nutsedge is also called “nut grass” or “water grass”. It is a sedge type grass that grows from a nutlet in the ground. The nut in the ground never really goes away. The amount of rainfall we have determines the amount of nutsedge you see.
Nutsedge is most noticeable in ditches or any place where water stands frequently – it will also show up in your flowerbeds. However, with the amount of recent rainfall we’ve had in some of our service areas like Tulsa and Springdale, nutsedge has become a big problem. Our grassy weed applications help, but it’s an ongoing battle. Most of the products we use must be applied twice within 7-10 days to be effective. When our schedule is thwarted, due to customers rescheduling, or more rain, we have to start again.
If you’re a do-it-yourself-er, first understand the difference between “selective” and “non-selective” when looking for a product. Non-selective will kill whatever you spray and usually contains glyphosate – Round-Up is one such product. Be very careful if you use RoundUp, because it will kill anything actively growing. It will kill nutsedge, but we think it’s best reserved for killing weeds in gravel areas, or weeds in the cracks of your driveway. You don’t want to kill your grass!
Selective herbicides are designed to target certain weeds. Products containing halosulfuron (like Sedgehammer) will control nutsedge and are best used when the plant is young. They are more effective when a nonionic surfactant is added. We use products like Certainty (containing sulfosulfuron,) which are available only to professionals. MSMA also works, but is more effective on yellow nutsedge than purple nutsedge. (Yes, there are two varieties of nutsedge…)
Please bear in mind that the spring pre-emergent weed control applications do not control summer grassy weeds like nutsedge, dallisgrass, fescue clumps, etc. Nutsedge doesn’t even show up until late April. As far as pre-emergents for nutsedge, there are some on the market. I believe Casoron (containing dichlobenil) is the only one available to homeowners, and it must be applied before the plants emerge. Other nutsedge pre-emergents available to professionals are Pennant, and Freehand. Both are very expensive and testing within our markets has so far proved too unreliable on a consistent basis for us to offer a nutsedge pre-emergent application.
So, if you’re having a problem with nutsedge, it’s likely due to the abundant rainfall we’ve had. If you buy a product to use yourself, be sure to follow the directions to the letter. Many products for nutsedge control will cause temporary yellowing to surrounding turf, so just expect it! It will look bad, but after a few mowings, it will be gone! (In flowerbeds, it’s best to just pull the nutsedge.)
Most of the grassy weed products we use may cause temporary yellowing. We know you don’t like to see that, but it’s necessary to get rid of the weeds. Grassy weeds are, after all, grass, so it’s no surprise that our material will yellow the grass in your lawn.