Weeds | Yellow Nutsedge

Yellow Nutsedge Info

Yellow nutsedge is a common summer weed. New seedlings and plants sprout from May-July. Yellow nutsedge is a perennial weed and has a triangular stem that is typical for plants in the sedge family.  Yellow nutsedge forms tubers or “nutlets” at the end of its rhizomes. These nutlets can remain viable for up to 10 years!

We take an aggressive stance against yellow nutsedge. It is able to quickly colonize an area, and looks very unsightly in the lawn.

Yes, yellow nutsedge pulls out of the ground easily. However, the roots usually shear BEFORE the nutlets and leave the dormant tubers behind, only to return later in the season or the following year. One yellow nutsedge plant can produce 100’s or even 1,000’s of tubers in a single growing season.

For this reason, we recommend treatment with herbicides. 

Description & Identification

As the name implies, yellow nutsedge is in the sedge family. Just like most sedges, yellow nutsedge has a triangular stem, shown in the photo below. 

Yellow nutsedge also has a lime green color that stands out in contrast to the deeper green of most lawns. The leaf tips are narrow and pointed. Usually nutsedge grows quicker than the rest of the lawn and is taller than most other grass species when it is time to mow. 

Above, you can clearly see the rhizomes developing. However, the nutlets that are usually on the ends of the rhizomes, broke off and persist in the soil around there area where this yellow nutsedge was collected.

Reproductive parts, i.e. flowers, are a very easy way to identify yellow nutsedge. Below is a photo of yellow nutsedge flowering. There are multiple yellow-lime green flower spikelets radiating from the tip of a single stem. It is important that flower heads are removed BEFORE seeds develop, or the nutsedge infestation can travel quickly.  Typically yellow nutsedge flowers from July-September. 

Treatment & Prevention

Stated earlier, chemical herbicides work best for this weed. Look for a systemic herbicide when selecting a control method. Systemic herbicides infect the entire plant and kill it completely. This trait is very important to ensure that nutlets are killed. 

Pre-emergent herbicides do little to prevent yellow nutsedge because it is a perennial weed. Yes, pre-emergents will prevent new yellow nutsedge seeds from germinating, but it will not prevent dormant plants and nutlets from sprouting. 

Glyphosate, the active ingredient in Round-Up, effectively kills yellow nutsedge. However, glyphosate is a broad spectrum herbicide and often causes collateral damage to nearby plants if the application is not performed carefully. For this reason, glyphosate works well in flowerbeds and gardens, but is not suitable for use in lawns. 

There are several products that will selectively kill yellow nutsedge in lawns. Some that we use include: Sedgehammer, Tenacity, and Dismiss. Each herbicide works differently. Always read and follow the label for application. Below is a photo of the three herbicides mentioned.