A frequently asked question about yellow nutsedge is “What is this grass weed?” Well, it looks like a grass but is really a sedge and it’s on my list of 10 Most Unwanted Weeds. Nutsedge spreads and grows rapidly in lawns, gardens and landscape beds and takes a stubborn determination to control once established.
Yellow nutsedge can be found in yards from Maine to California, it is a weed in both cool-season and warm-season lawns and most commonly a problem in wet or damp areas.
Yellow Nutsedge Cyperus esculentus (often called “Nutgrass”) gets its name from its yellow/brown seedheads and the tubers or nutlets that form at the tips of the rhizomes (spreading underground stems). The triangular stems grow upright and have glossy leaves that are a light green or yellow-green color and have a very distinct mid-rib. It looks ugly in lawns because it grows faster than grass and really sticks out…disrupting the uniform appearance of a groomed lawn.
What to look for:
- Waxy, light green or yellow-green leaves
- Leaves have a very distinctive mid-rib
- Upright, triangular stems
- Yellow-brown seed heads
- Thrives in wet areas
- Small tubers (about ¼” in size) on tips of rhizomes
- Purple Nutsedge
- Green Kyllinga
- Also called Nutgrass
- Warm-season perennial
- Spreads by nutlets and seeds
- Thrives in wet sites
Sedges love moist areas and sites that stay wet from excessive irrigation or poor drainage are likely to become infested with nutsedge. In late June and into July, the nutlets start to form on the tips of the rhizomes. It is important to work on weed control before the nutlets form because several new plants can grow from a single nutlet and they remain in the soil for several years.
Lawn Weed Control
It can take several years to get rid of this weed, new plants are continuously produced from the nutlets left in the soil. Timing and persistence are the keys to winning the battle against nutsedge, weed control is always most effective on young, actively growing plants. Whether hand weeding or using chemical control, it is important to get after young plants before they produce nutlets or go to seed–this will reduce the number of new plants.
Nutsedge is easy to hand weed however, it should be pulled when plants are young, and then continue to scout the area to remove new plants as they appear.
**Important** Be sure to read and follow the directions on the label if you choose to use an herbicide for weed control. It is a violation of federal law to use ANY pesticide in a manner that is inconsistent with the label.
Chemical control options include non-selective and selective herbicides. Make sure the herbicide either contains a non-ionic surfactant or be sure to add one to the tank mix. The surfactant will make herbicide applications work better by helping the chemical stick to the glossy, waxy leaves and penetrate into the plant.
Glyphosate (Roundup) is an effective non-selective herbicide that can be used on nutgrass in landscape beds. Glyphosate takes about a week to work and follow-up applications in two or three weeks are usually required.
Here’s a helpful video from the University of Nebraska Extension:
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