Annual Sedge

Description

This species is one of the few sedge species that is a true annual. As a result, this sedge is easier to control than many other perennial sedges. Annual sedge has a very characteristic seedhead that tends to be relatively large compared to other sedges, and the seedhead is flattened with a toothed outline. Annual sedge tends to have a more "clumpy" appearance than other sedges particularly when it occurs in low densities. This sedge also tends to emerge later in the spring / summer than most other sedge species.

Cultural Control

This species is one of the few sedge species that is a true annual. As a result, this sedge is easier to control than many other perennial sedges. This sedge also tends to emerge later in the spring / summer than most other sedge species. Sedges are weeds that resemble grasses but unlike grasses, sedges have three-sided or triangular stems. It is important to properly distinguish sedges from grasses because management is totally different. Sedges are plants that thrive in wet or poorly drained soils but can survive in areas that are not wet. Because of frequent irrigation in highly maintained turf, sedges often thrive in the turfgrass environment. Sedges often become established in wet areas and spread to other areas that are not poorly drained or wet areas. Therefore, it is important to recognize areas where sedges can become established and prevent spread of these sedge species to other areas of the golf course or landscape.

Chemical Control

Herbicide and Formulation Amount of Formulation per 1,000 sq ft Amount of Formulation per Acre Pounds Active Ingredient per Acre
Preemergence and Postemergence Control
mesotrione, MOA 27 (4 SC) (Tenacity) 0.092 to 0.183 fl oz 4 to 8 fl oz 0.125 to 0.25
Precaution and Remarks: Use on residential turf, golf courses (not greens) and sod farms for pre- and postemergence weed control. Tolerant turfgrasses include St. Augustinegrass, centipedegrass, tall fescue, fine fescue, Kentucky bluegrass, and perennial ryegrass. Add a nonionic surfactant and repeat application after 2 to 3 weeks for improved postemergence control. Tank mix with prodiamine 65 WG for extended preemergence grassy weed control. Can be applied at seeding to all tolerant grasses except fine fescue. After turf germination, wait 4 weeks or until turf has been mowed twice before making a postemergence application. Also controls henbit, chickweed, dandelion, white clover, Florida betony, Florida pusley, ground ivy, oxalis, wild violet, creeping bentgrass, and yellow nutsedge.
[sulfentrazone + prodiamine], MOA 14 + 3 (4 SC) (Echelon) 0.184 to 0.826 fl oz 0.5 to 2.25 pt 0.25 to 1.125
Precaution and Remarks: For use in residential and institutional lawns, athletic fields, sod farms, golf course fairways and roughs, roadsides, utility right-of-ways, railways, and industrial areas. Apply to turf following a second mowing if a good root system has been established. Apply up to 12 fluid ounces per acre to bentgrass at 0.5 inch or higher, fine fescue, and perennial ryegrass. Apply 18 to 24 fluid ounces per acre to perennial bluegrass, tall fescue, and all warm season grasses except St. Augustinegrass (do not apply) and bermudagrass (apply 18 to 36 fluid ounces per acre). For sod production, apply 6 months after establishment, and do not harvest within 3 months. Do not apply with adjuvants or surfactants. [Sulfentrazone + prodiamine should not be applied to cool-season turf with N-containing fertilizers unless some short-term discoloration is tolerable.
Postemergence Control
Herbicide and Formulation Amount of Formulation per 1,000 sq ft Amount of Formulation per Acre Pounds Active Ingredient per Acre
MSMA, MOA 17 (6 SL, 6.6 SL) (various brands) several concentrations 1.82 to 4.5
Precaution and Remarks: MSMA is only registered for golf course, sod farm, and highway right-of-way use. Bermudagrass, bluegrass and zoysiagrass are tolerant. Injury may result on bentgrass, fescue and also St. Augustinegrass grown for commercial sod production only. Do not use on carpetgrass or centipedegrass. MSMA restrictions: For existing golf courses, spot treat (100 square feet per spot) not to exceed 25% of total acreage. For new courses, make 1 broadcast application per year. For sod farms, make 1 to 2 broadcast applications per year and maintain 25 feet buffer around permanent water bodies. For highway rights of way, make 2 broadcast applications and maintain 100 feet buffer around permanent water bodies.
bentazon, MOA 6 (4 SL) (various brands) 0.75 to 1.5 fl oz 1 to 2 qt 1 to 2
Precaution and Remarks: For control of yellow nutsedge in established bluegrass, fescues, bentgrass, ryegrass, bermudagrass, bahiagrass, St. Augustinegrass, centipedegrass, and zoysiagrass. Apply to yellow nutsedge when actively growing under good soil moisture conditions. Additional applications may be made at intervals of 10 to 14 days until nutsedge is controlled.
imazapic, MOA 2 (2 AS) (various brands) 0.092 to 0.184 fl oz 4 to 8 oz 0.063 to 0.125
Precaution and Remarks: For use on unimproved centipedegrass after complete greenup only. Not for use in home lawns. Do not use on other turfgrass species. A repeat application may be needed on tough to control perennial weeds such as bahiagrass. The highest labeled rate may discolor centipedegrass by causing a red color.

Species Data

  • Growth Season / Life Cycle
    • summer annual weed
  • Seed Arrangement on Spikes
    • tightly bunched; seedhead clusters of flat green spikes on stalks
      Figure 1, Figure 2
  • Seedhead Spikelet Shape
  • Tuber Type
    • none
Figure 1. Annual sedge.Figure 1. Annual sedge.Figure 2. Annual sedge seedhead.Figure 2. Annual sedge seedhead.Figure 3. Annual sedge.Figure 3. Annual sedge.Figure 4. Annual sedge seedhead.Figure 4. Annual sedge seedhead.