Shut down sedges

March 22, 2019 -  By
Photo: PBI-Gordon Corp.

Lawn care operators can identify yellow nutsedge by its wide leaves with straight edges that abruptly come to a point. Photo: PBI-Gordon Corp.

Yellow and purple nutsedge are grasslike weeds in the sedge family. If left uncontrolled, nutsedge can spread and return year after year. Here are some tips to identify the yellow and purple varieties of the weed and keep your turf sedge-free.

Yellow/purple nutsedge

Know your enemy:

  • Grasslike weed, but not a grass;
  • Triangular stem;
  • Shiny, glossy leaf surface;
  • Warm-season, perennial;
  • Fibrous root system that produces tubers that can survive years in the soil; and
  • Can grow anywhere, but particularly thrives in southeastern climates due to wetter soils and warmer temperatures.

Yellow nutsedge

Photo: PBI-Gordon Corp.

Photo: PBI-Gordon Corp.

Know your enemy:

  • Emerges in late spring and actively grows in summer;
  • Sprouts yellow seedheads;
  • Features wider leaves with straight edges that abruptly come to a point; and
  • Sprouts single tuber growths (called nutlets) below ground.

Purple nutsedge

Know your enemy:

  • Purple seedheads (smaller than yellow nutsedge seedheads);
  • Narrow leaves that taper slowly to a point; and
  • Purple nutsedge tubers grow in chains underground. For this reason, it’s typically harder to control than yellow nutsedge.
Photo: PBI-Gordon Corp.

Purple nutsedge features narrow leaves and can be more difficult to control than yellow nutsedge. Photo: PBI-Gordon Corp.

Combat strategy:

  • Typically sedges thrive in wetter soils and poorly drained, low-lying areas;
  • When laying sod, ensure the turf is free of nutsedge tubers;
  • Check for drainage issues and soil compaction. Check irrigation heads for possible overlap that may cause turf to become more saturated;
  • Consult with university extension experts to research the best products for your turf;
  • Be sure to use products labeled specifically for nutsedge;
  • Apply a postemergent herbicide before the sedges sprout tubers — in late spring/early summer or when signs of sedge active growth are observed (in temperate climates, around June 15 — earlier for warmer climates, later for colder climates);
  • Apply postemergent herbicides such as pyrimisulfan, halosulfuron, trifloxysulfuron, sulfentrazone, imazosulfuron or a combination product containing carfentrazone and one of the aforementioned products; and
  • Generally, purple nutsedge in particular will need repeat applications of a postemergent — at least two for acceptable control.

Sources: Tina Bond, Ph.D., herbicide/fungicide technical service, FMC; and Eric Reasor, Ph.D., southeast research scientist, PBI-Gordon.

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