How to Get Rid of Cyperus Rotundus

Cyperus rotundus, also called purple nutsedge or nutgrass, has smooth, grass-like foliage and reaches a height of up to 39 inches. It produces reddish-purple blooms and grows quickly in practically any soil, spreading through a vigorous root system and by seed. Cyperus rotundus can survive drought and extreme heat, but it struggles to survive in shade. This weed can be controlled through chemical and mechanical efforts, though more than one attempt is often needed to completely eradicate the plants.

Things You'll Need

• Spade
• Protective gloves and clothing
• Nonselective herbicide
• Selective herbicide
• Tiller
• Weed mat
• 10- to 12-inch spikes
• Flat washers
• Mulch

Instructions

1. Dig Cyperus rotundus tubers from the ground. This is a time-consuming method, but it is effective if the weed is growing among desirable plantings that would be damaged by the use of herbicides.

2. Put on protective gloves and clothing that will cover exposed skin.

3. Spray Cyperus rotundus with a nonselective herbicide when blooms appear. Choose a dry, windless day for treatment and avoid getting the product on the vegetation of surrounding plants. Make repeat applications every four to six weeks if necessary

4. Apply selective herbicide to Cyperus rotundus plants that have invaded lawns. Selective herbicide destroys weeds without damaging most types of warm-season turf grass. Make the application when the weeds have at least three leaves.

5. Control Cyperus rotundus in garden plots by first tilling the soil to eliminate all vegetation.

6. Stretch weed cloth over the desired area and drive 10-to 12-inch spikes through the mat and into the soil. The spikes should be held securely with flat washers. Don't pull the weed cloth taut, as this may allow Cyperus rotundus blades to penetrate the mat when they re-emerge.

7. Remove the weed mat after two to four months.

8. Spread 3 to 4 inches of mulch over the site to keep Cyperus rotundus seeds that remain in the soil from sprouting.

Tips & Warnings

• Herbicides are toxic and should be kept away from children and pets.

References

• University of Florida IFAS Extension; David W. Hall, et al.; February 2009
• University of Hawaii at Manoa Cooperative Extension Service; Purple Nutsedge Control in Turf and Ornamentals; J. T. Brosnan, et al.; January 2008