Is Nutsedge Driving you Nuts?

Good to Know

Mar 28, 2013

What is nutsedge?   Nutsedge is an aggressive and persistent weed found in turfgrass, shrub and flower beds. It grows faster than turfgrass and is lighter in color spoiling the smooth carpeted look of turf areas.

There are 2 common types in California:

1. Yellow nutsedge (Cyperus esculentus) - grows throughout California

2. Purple nutsedge (Cyperus rotundus) - grows mostly in the southern portions of California

Many people call these weeds "nutgrass" since they are similar in appearance to grass; however, they are not a grass but are a sedge. Sedges are grass like plants from the family of cyperaceae. They have triangular, solid stems with leaves in three vertical rows and small flower spikelets. There are more than 5,500 species of sedges.

Some more common sedges are the water chestnut (Eleocharis dulcis) and the papyrus sedge (Cyperus papyrus) from which Ancient Egyptian writing material was made.

Nutsedge produce tubers, which are incorrectly called "nuts" or "nutlets".  Tubers are produced on underground stems called rhizomes and can grow 8 - 14 inches below the soil surface with a survival rate of 1 - 3 years.  Buds on the tubers sprout and form new plants and can form into patches that can reach a diameter of 10 feet or more.

Tubers are vital for the nutsedge to survive and thrive. Small plants should be removed before they develop tubers which are usually before they develop 5-6 leaves.

The best chance of managing nutsedge is a combination of cultural, mechanical and chemical control.

Cultural Control:  Nutsedge usually develops in moist soil and once it is established it can live in normal or even drought like conditions. Irrigation amounts and timing should be monitored as well as proper drainage. Both of these can create extra moisture and encourage the growth of nutsedge.

Mechanical Control:  Very small amounts of nutsedge can be dug out (you must dig at least 10 inches deep and at least 8-10 beyond the diameter of the leafy portion of the above ground plant.

Chemical Control:  Nutsedge can be controlled with the use of herbicides. Post emergent herbicides move quickly through the plant and must be applied to the small plant before tubers have developed. Preemergent herbicides will greatly reduce the amount of nutsedge. Additional applications are necessary to control the plant over time.

Credits:  Clemson University, SC,  UC Davis, Statewide Integrated Pest Management Program, Agriculture and Natural Resources