How Do I Get Rid of Zoysia?

Americans first started growing zoysia (Zoysia japonica) in their lawns back in the early 1900s. Today, you can find it in golf courses, lawns and other landscaping areas throughout U.S. Department of Agriculture plant hardiness zones 5 through 10. Whether your zoysia has escaped its confines and is invading other parts of your backyard, or if you want to eliminate an entire zoysia lawn to make room for new plants, you have options for killing and eliminating this grass species.

Harness the Sun's Power

Solarization works effectively against warm-season grasses, such as zoysia, and kills the grass within two months without using toxic herbicides. For the best results, water your zoysia and use enough irrigation to moisten the soil to a depth of a foot. Cover the grass with a clear plastic tarp. Tarp comes in various sizes; look for one labeled as 1-millimeter-thick for the fastest results, or 1.5- to 2-millimeters-thick for windy areas. Weigh down the edges of the tarp with rocks, bricks or similar objects. The sun's ultraviolet rays will bake the underlying soil, killing your zoysia grass within six to eight weeks.

Smother the Grass With Darkness

Too much sun, as in the case of solarization, kills zoysia. The opposite also works; by covering your zoysia with an impenetrable layer of organic matter, you block out the sun's life-giving rays and kill the grass. An extra advantage: this method causes the zoysia to decompose, thus adding nitrogen and other nutrients to your gardening soil. First, cover your grass with a layer of newspapers that's six to eight sheets thick. Then, cover the newspaper with 2 inches of compost followed by 2 inches of wood chips. Over the course of a couple months, the underlying zoysia will die and decompose.

Spritz the Grass With Chemicals

For the fastest results, spray the zoysia with a nonselective herbicide formulated with glyphosate, which kills zoysia and all other plants. For the best results, wait for a dry day when no wind or rain is in the weather forecast. Pull on protective gear, including shoes, pants, a long-sleeved shirt, gloves and safety goggles. Apply any glyphosate-based herbicide to the zoysia according to the manufacturer's product-specific guidelines, as toxicity and potency varies by product. For example, Roundup's Ready-To-Use Weed & Grass Killer III comes with no mixing requirements; simply spray it on the zoysia using the bottle's included spray gun at a rate of 1 gallon for every 300 square feet. In contrast, for effective use against grass, Bonide's Kleenup Weed & Grass Killer 41% Super Concentrate requires you to mix it at a rate of 3 tablespoons per gallon of water, with every gallon sufficiently treating 300 square feet of zoysia.

Cut Out the Zoysia

Physically removing your zoysia is back-breaking work, but it's faster than waiting for solarization or smothering to take effect, and it avoids the toxic use of herbicides. Using a sharp spade, cut your zoysia lawn into 1-foot-wide strips. Then, using the spade or a gardening fork, pull up one end of the strip and roll it forward to basically strip it from the soil surface. Rake the bare soil left behind to remove any stray bits of grass or weeds. Observe the area for two to three weeks; if you left behind bits of zoysia grass, it may start regrowing. Hand-pull any straggling remnants of your lawn on an as-needed basis until you completely eliminate the zoysia.