Yellow Nutsedge and Purple Nutsedge

Identification & Culture:

Yellow and purple nutsedge, as their names imply, are distinguishable by their color. These grassy weeds also have some other distinguishing characteristics, including solid, triangular stems (compared to most grass stems which are hollow), and leaves with a waxy surface that can make it difficult for herbicides to penetrate.

Nutsedges are unique weeds because they produce tubers that look like peanut-sized potatoes in the soil. One plant is capable of producing thousands of tubers that can patiently wait in the soil for up to 10 years before emerging. These tubers can be produced at the ends of rhizomes (underground runners), so they can occur several feet away from the mother plant.

Both species can be troublesome in low, wet areas of your yard. They are warm-season plants, with yellow nutsedge more prevalent in the northern states and purple nutsedge more prevalent in the south. The nutsedges grow faster than many other grass species, especially in the northern climates, and can often be seen growing a few inches above the rest of the lawn a few days after mowing.

There are very few herbicides that control yellow nutsedge currently available to homeowners – look for the active ingredients, halosulfuron (found in Sledgehammer™ ), sulfosulfuron (found in Certainty® ), or sulfentrazone (found in Dismiss® or Solitaire® ).

Help your lawn battle nutsedge with these basic practices: Fertilize often (4-5 times year), mow higher (leave the grass 3-4 inches tall) and only water when necessary because this weed loves moisture.

You can also very carefully use a non-selective herbicide, such as RoundUp® , to kill these weeds. But DO NOT spray it directly on the plant, because it will kill the surrounding grass. Instead, because purple and yellow nutsedges grow faster than most, it can be relatively easy to “wipe” the plants with Roundup® a few days after mowing when they have grown a bit higher than the rest of the lawn. Wiping is a technique used in weed control to apply non-selective herbicides in a selective way. You will need to wear an impermeable rubber or latex glove with a cotton glove over it. Soak up some of the Roundup mixture and carefully wipe the nutsedge plants with your gloved fingers. Remember that if you have soaked up too much of the mixture and the cotton glove is dripping wet, you will have small dead spots all over the lawn.

Purple and yellow nutsedges have very shallow and fibrous root systems and it is very easy to separate the plants from the desirable turfgrass around them. Because of this, hand-pulling purple and yellow nutsedges is very easy and effective. Try to pull nutsedge plants while they are still young so they have very little time to produce unseen tubers in the soil