Considerable interest has developed in the use of zoysiagrass for lawn purposes. It is a good hot-weather grass on poor soil. Advertising, which has also created interest, has ranged from fair to misleading. It is not a miracle grass, as some advertising would lead one to believe. Zoysiagrass is neither all good nor all bad--it is desirable on some turfgrass areas and the wrong grass to use on others. Test plantings, trials, and observations of zoysiagrass have been made on Long Island, in New Jersey, and nearby states for more than 25 years. The purpose of this leaflet is to summarize the present knowledge on the desirability, the use and the culture of zoysiagrasses. In part, the decision to use or not to use zoysiagrass involves personal taste on its brown winter color. Before purchasing or planting zoysiagrass, you should observe a zoysiagrass lawn during the fall, winter and spring. Consider the following advantages and disadvantages of zoysiagrass before deciding on its use.

Advantages of Zoysiagrass:

• Zoysiagrass grows especially well during the hot summer months.
• When established, it produces a thick, dense, cushiony turf.
• Its thick growth prevents and controls crabgrass and summer weeds.
• It has a good green color during the hot summer months when the cool-season grasses may become unattractive.
• It withstands close mowing (1/2 to 1-1/4 inches).
• Grows in most types of soil with proper management.
• Withstands wear and tear during the summer.
• Can survive severe heat stress.
• Tolerates low fertility once it is well established.
• Requires less water than most cool-season turfgrasses.

Disadvantages of Zoysiagrass

• It loses its green color and becomes brown and straw colored about mid-October. It remains this color until about mid-May. In contrast, cool-season grasses usually have good green color about 10 months or longer. Even in mid-winter, cool-season grasses have some green left.
• Propagation by vegetative establishment, with stolons or sod plugs, is necessary. This method tends to be expensive and laborious. Seed is generally unavailable and impractical. Seeded types are generally very coarse textured.
• Zoysiagrass establishes slowly. Under ideal conditions, it may give cover in one season. Normally, two to three years are required.
• Winter annual weeds tend to be more of a problem in zoysiagrass than in cool-season turf.
• Once established, it is difficult to eliminate and may be a nuisance around plant beds. It can also invade a neighbor's lawn or garden.
• Injury from persistent winter traffic can be severe while zoysiagrass is dormant.
• When brown and straw colored, it is flammable and may be a fire hazard when allowed to grow tall near wooden buildings.
• Since it is tough and grows densely, it requires more regular mowing in summer.
• While it tends to have less disease than most turfgrasses, it is subject to rust and fairy ring. Fusarium blight has caused serious problems on occasion.
• It is not satisfactory for shade.

Guidelines for Use:

Zoysiagrass should be used primarily in situations where a summer lawn is of primary importance. The unattractive winter color is not objectionable on lawns of summer homes. The same may apply around swimming pools.

Zoysiagrass grows best and is most useful for areas which have sandy or gravelly soils. It is sometimes put to good use on sunny, south or southwest slopes and on poor or sandy soils. It is occasionally used on curb strips between sidewalks and roads.

Winter-Hardy Varieties:

Some zoysiagrass grown in the southern United States may winterkill seriously in the Northeast. The following types, which are Zoysia japonica or have stock of this species, are winter-hardy. 'Meyer', released from Beltsville, Maryland in 1951, has been the most commonly used variety. 'Emerald', another variety, was introduced from Beltsville, Maryland in 1955. It has finer leaves than 'Meyer'. This grass appears less hardy than some, but it has survived more than 10 years on Long Island. Japanese lawngrass, Zoysia japonica, is somewhat coarser than 'Meyer.'

Establishment and Maintenance:

A well-prepared weed-free plant bed is desirable when establishing zoysiagrass. Vegetative material may be planted as sprigs or plugs. One square foot of sod may provide as many as 500 sprigs or 36 two-inch plugs. A plug is a round or square piece of sod usually two to four inches in diameter with a core about 2 to 2 1/2 inches in depth. The term "sprig" applies to a vegetative portion of the grass plant and usually includes the leaves, a stolon (runner) and some roots.

Zoysiagrass is best planted during its early growing season from mid-May through June. Later plantings fail to cover the soil before frost and they will experience more winterkill.

• Plugging - Place plugs 2 1/2 inches in diameter (preferred over 2 inches) at 8- to 12-inch intervals. Press plugs into a similar-size hole to get good soil contact. Do not cover the plugs with soil or allow the plugs to remain elevated. A hard steel plug cutter can be used to cut the plugs in the nursery. Such a tool may also be used for cutting holes in the lawn into which the plugs are planted.
• Sprigging - Sprigging into an existing lawn is not as desirable as plugging. Sprigs should be planted in well-prepared, weed-free plant beds. Sprigs are obtained by tearing a piece of sod apart. Each sprig should be at least three inches in length and contain one or two nodes. Sprigs are planted with one end below the soil and the other end with the leaf shoots above the soil. Fresh sprigs are planted 4 to 12 inches apart in rows and 8 to 12 inches between rows.
• Liming - Soil acidity for zoysiagrass should be maintained as for most regular grasses. The pH should be between 6.0 and 6.5. Have the soil pH tested and add limestone according to the pH results. See our GreenShare Factsheet on soil testing for more information on having your soil tested.
• Fertilization - At the time of establishment of zoysiagrass on a rototilled or loosened plant bed, apply a half rate of 5-10-5, or 10 pounds per 1,000 square feet. Use a moderate-release- type fertilizer. First season of establishment with sprigs or plugs, repeat the 1/2 rate of a complete fertilizer every three or four weeks through early August. Use a slow-release fertilizer for these applications. After establishment, late May fertilization is best; but it can be fertilized through early August. Established zoysiagrass requires less fertilizer than most turfgrasses and it will endure long periods without fertilization. Do not use more than one pound of actual nitrogen per 1,000 square feet per application. In order to determine if a fertilizer is fast or slow release, and to learn how to determine rates, see our GreenShare Factsheet on Developing a Fertility Program for Lawns.
• Mowing - Since zoysiagrass is grows slowly, it does not require as frequent mowing in cooler growing weather as do some turfgrasses. Mowing once a week during this season, however, will help to maintain smooth, well-groomed turf. It is a tough grass that grows more rapidly in hot weather when it may need tow or three mowings per week. The mowing height should be 1/2 to 1- 1/4 inch. Zoysiagrass tends to form a dense mat when mowed low. Low mowing favors this grass and is especially beneficial when you are trying to get plugs started in established lawns. A close mowing in late April will remove brown leaf tips and encourage earlier greening.
• Watering - Newly planted plugs and sprigs of zoysiagrass should be kept moist during the first two or three weeks to prevent drying out. Established zoysiagrass turf does not require as much water as most Northern lawn grasses. It will survive the early off-color wilt stage, but it should be watered when a darker gray-green or loss of green color develops in extended drought periods. A slow application of one to two inches of water may be necessary on established turf during these times.
• Chinch Bugs, Billbugs and Sod Webworms - These insects may cause damage from June through September. Preventive or curative treatments when the insects are active may be necessary to prevent serious damage. See individual factsheets on these insects for control recommendations.
• Weed Control - After the lawn is well established, it usually has little need for weed control. Occasionally, a few broadleaf weeds and wild garlic (onion) do appear. These can be controlled with the common materials used for our cool-season grasses.
• Thatch Control - Thatch - the accumulation of stems, stolons, roots, etc. above the soil surface - is one of the most common problems. You can remove some thatch with a vertical mowing device or power raking machine. Remove thatch in mid-to-late spring, usually every year or two, depending on how much the grass is fertilized.
• Dyeing the Lawn - Zoysiagrasses, which turn straw colored and brown in the fall with the first heavy frost, can be colored green for the winter months. Several pigment-type colorants are available at some garden supply stores for dyeing brown lawns. A single application of dye after the zoysiagrass is completely dormant will usually last all winter. Although artificial in appearance, the green dyed lawns may look better than straw-colored ones.

Elimination of Zoysiagrass

Many people plant zoysiagrass with the hope that it will solve all their lawn problems. After observing it for one or two winters, some people change their minds and hope to eliminate it. Their task is not easy.

If you do not wish to use chemicals, or if complete or fast elimination is not required, you can use the following procedures.

1. Fertilize in September and October only.
2. Raise the height of cut to 3 inches or higher.After several years, this type of management encourages the cool-season turfgrasses to overtake the zoysiagrass.

Faster elimination is possible. You would have to kill the entire zoysia lawn with a non-selective weed killer such as glyphosate, then renovate and reseed (CAUTION: glyphosate is not available for sale in Rhode Island--you will need to order it from an advertisement in a gardening magazine or newspaper).

Adapted from Tom Kowalsick, Cornell Cooperative Extension, 2001