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Purple nutsedge WN 3-19 feat

Use pre-emergent herbicide for purple nutsedge

In The Garden and Around The Lawn

There are many pleasant landscape related experiences in Wakulla County during March. For the homeowner it is a time of low-impact duties in the garden and around the lawn.

The leaves and pine straw are raked up (or should be) and in the flowerbeds. It is time to pull out the lawnmower and service it, but it will not be used for weeks.

Stop Warm Season Weeds

There is, however, one job which should be done now, Now, NOW. That is spray the lawn with a pre-emergent herbicide to stop the warm season weeds, especially the dreaded curse purple nutsedge, from emerging.

Purple nutsedge, Cyperus rotundus, can grow from every possible sunny location with soil.  This non-native plant is a rapidly spreading perennial which will take every opportunity to colonize new locations.

The purple designation is in its name because there is a purple-tinged section of this sedge where it emerges from the ground.  The plant is sometimes referred to as purple nut grass because of its long narrow leaves and its erect growth pattern originating from a nutlike basal bulb.

Other Sedges in Wakulla County

There are other sedges in Wakulla County, but only yellow nutsedge is identified by a specific color.  It is sometimes called chufa and is a popular feed for wild turkeys, and turkey hunters.


Purple nutsedge WN 3-19 insert

Rhizomes will produce bulb-like nutlets which branch out in all directions from this sedge. Early March is the time to apply pre-emergent herbicide to stop this problem species. Photo By: Les Harrison

The dark green, smooth leaves blend in easily with many turf grasses during the growing season.  Beneath the soil’s surface and out of sight, the root system spreads in every direction.

Purple nutsedge’s roots are a series of dispersing rhizomes and tubers or bulbs identified as nutlets.   Each nutlet sprouts a new tuft of grass-like leaves and continues growing the rhizomes.

Sedge Quickly Crowds

The dense population of this sedge quickly crowds out most other plants, but especially turf and forage grasses.  It can reach a height of 18 inches on its triangle shaped stem.

The root system’s design assures this plants continued success.  If pulled, the rhizomes break off leaving a large number of nutlets to develop and emerge independently at a later date.

If plowed or tilled, the nutlets are detached and spread to new and inviting locations.  Many times nutlets lodge in tillage equipment only to shake loose and deposited in un-colonized locations.

Most post-emergent herbicides have little effect on this sedge’s hardy root system.  Only selected pre-emergent herbicides will prevent many of the nutlets from germinating in spring, if properly applied.

Nutsedge Loves Wakulla County’s Sandy Soils

Wakulla County’s sandy soils provide an ideal growing environment for purple nutsedge.  The occasional periods of saturation from storms do not deter this plant’s rapid growth and expansion to new areas.

Purple nutsedge’s extreme competitive nature is a heavy consumer of plant nutrients. It robs rivals of important compounds necessary for their survival, and produces an allelopathic substance which is toxic to some plant competitors.

Purple nutsedge is found in many locales in North America where the environment is hospitable to its growth.  The autumn cool and shorter days send this exotic pest into dormancy, but the seeds of next year’s crop, and associated landscape problems, are just under the surface.

Just like desirable turf in north Florida, purple nutsedge will not grow in heavy shade. Typical of most weeds, it only reduces leisure time.

Now, Now, NOW is the time to get purple nutsedge under control. It is a good thing March has so much time to get ahead of a problem which will consume so much effort later in 2019.

To learn more about purple nut sedge in Wakulla County contact the UF/IFAS Wakulla County Extension Office at 850-926-3931 or

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information, and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions, or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A&M University Cooperative Extension Program, and Boards of County Commissioners Cooperating

6 Comments on “Use pre-emergent herbicide for purple nutsedge

    • Joshua – The pre-emergent herbicide you use depends on the types of weeds you wish to control. Broadleaf weeds like dandelions are different from the purple and yellow nut sedges, and therefore you will use two different pre-emergent herbicides. I am attaching a publication by the University of Florida about nut sedges, and towards the end of the document is information about pre- and post-emergent herbicides.
      You will want to apply a pre-emergent herbicide before the weeds begin to germinate and appear in your lawn. For the cool season broadleaf weeds like dandelion, betony, henbit, etc. It is best to apply this in late October or early November and then do a second application in late December or early January. For warm season broadleaf weeds and sedges, you will want to apply the herbicide in late February or early March.
      Be sure to read the label to make sure the herbicide you apply will be safe to use on your particular lawn type.

      If you have any questions or suggestions for future articles please email to

  1. Mr. Harrison ,I live in N-E Arkansas and have Yellow Nut Sedges. When is
    the best time to spray premergence,plan on using Dismis herbicide.
    Lee Mayhan

    • Lee – ‘Dismiss’ is a post-emergent herbicide that you use on growing sedges. Two pre-emergent herbicides that have some suppressive effect are Tower and Free Hand. I am also including a link to a detailed publication by the University of Florida that includes more information about pre- and post-emergent control of nut sedges.
      Our Master Gardeners have used the ‘Dismiss’ brand with sulfentrazone with decent results. It does need to be re-applied 3-4 times for good results.

      If you have any questions or suggestions for future articles please email to

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