What's That Tall Weed In My Lawn?....Yellow Nutsedge

Yellow Nutsedge is a common weed found in many home lawns and other turfgrass areas in Missouri. The color and rapid growth rate make yellow nutsedge a prominent distraction in the aesthetics of high quality lawns. In addition to home lawns, this weed is also a significant problem in the turfgrass areas of parks, athletic fields, and golf courses.

Yellow nutsedge is distinctive and relatively easy to identify. The stems are stiff, triangular-shaped and yellow-green in color. The leaves are also yellow-green, can be wide bladed with a thick mid-vein and a very waxy covering. The shallow, fibrous root system often produces many nut-like tubers, which are underground food storage organs. Each of these tubers can germinate and produce new plants.

Yellow nutsedge is a warm season perennial plant. The above ground foliage does not survive winters. However, as soils warm during the late spring and early summer period, germination of tubers and seed produced by plants from previous years are capable of producing new yellow nutsedge plants. Heavy infestations of this weed in lawns and other turfgrass areas usually become readily apparent in July and August.

The color, texture, and growth habit of yellow nutsedge all contribute to aesthetic incompatibility with the desirable lawn turfgrasses. In addition to the aesthetic differences, the leaves of this weed have a rapid rate of vertical growth resulting in their frequent protrusion above the canopy of the desirable grasses. Combined, these distractions make lawns unattractive during the summer. Yellow nutsedge thrives under warm, wet conditions and can often be found in low, damp areas of lawns. This weed is often most problematic during summers after rainfalls.

Unlike most lawn weeds, yellow nutsedge is not controlled with applications of traditional annual grass weed or broadleaf weed control products. This weed is a member of the sedge family and requires the use of very specific herbicides to achieve satisfactory control.

If only a few yellow nutsedge plants are present, hand pulling may be the best way to selectively eradicate the weeds. Begin physically removing the weeds as soon as the weed plants are observed. Removal of the entire plant including root systems is necessary. Pulling mature plants is difficult. These plants will often break off at the soil surface allowing regrowth and tuber development to continue. This approach is effective only if performed on a regular basis.

The most effective turfgrass herbicide currently available for yellow nutsedge control is "Manage" (halosulfuron). Even with the use of these herbicides, a few weeks time may be required to eliminate the plants that are present and additional, repeat applications to control germinating nutlets may be necessary at a later time. Because of the seed and tubers that remain in the soil, repeat infestations in subsequent years should be anticipated.