William E. Pound
John R. Street
Yellow Nutsedge (Cyperus esculentus L.) is a common weed found in many home lawns and other turfgrass areas in Ohio. The color, growth habit, 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, industrial grounds, athletic fields, and golf courses.
Yellow nutsedge is distinctive and relatively easy to identify. The stems are erect, triangular-shaped and yellow-green in color. The leaves are also yellow-green, wide (0.38 to 0.50 inch) 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. Each new plant can also produce rhizomes which can give rise to additional new plants.
|Figure 1. Yellow nutsedge|
Yellow nutsedge is a warm season perennial plant. The above ground foliage does not survive winters in Ohio. 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.
|Figure 2. Yellow nutsedge rhizomes|
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 elongation resulting in their frequent protrusion above the canopy of the desirable grasses. Combined, these distractions make lawns unattractive during the mid to late summer period. 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 with above normal rainfall. Management and environmental factors, including improper mowing, nutrient deficiencies, insect damage, drought stress, etc., which stress or reduce the density or competitive ability of the desirable turfgrasses, will often lead to increased populations of yellow nutsedge.
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. Regardless of the control strategy selected, the plan should be initiated when the weeds are young and immature. Eradication from lawns, although difficult, can be accomplished through the following approaches.
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. After removal, homeowners are advised to recheck the area periodically for regrowth. This approach is effective only if performed on a regular basis.
Where large patches of nutsedge are present, control through the use of herbicides may be the only satisfactory option. Homeowners may purchase, through retailers, herbicides to eliminate this weed. The performance of these products is dependent on the user accurately following the "Directions For Use." Normally, two applications are required with the repeat application made 10 to 14 days following the initial application. When applying control products, avoid mowing three to five days before and after treatment. To ensure adequate herbicide absorption, do not water the lawn for at least 24 to 48 hours after product application. Applications should ideally be initiated in the late spring/early summer when the nutsedge is young, actively growing, and is most sensitive to herbicidal control. Once this weed matures, control is difficult regardless of the treatment schedule.
The most effective turfgrass herbicides currently available for yellow nutsedge control are "Basagran" (bentazon) and "Manage" (halosulfuron). These herbicides are not sold through typical retail outlets. Homeowners desiring applications of either of these two chemical controls are encouraged to contact a licensed, commercial lawn applicator. 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. As with the products available to homeowners, these herbicides perform best when treatments are made on young, actively growing nutsedge plants.
Homeowners should make note of the control strategies that are successful. Because of the seed and tubers that remain in the soil, repeat infestations in subsequent years should be anticipated.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-6181