Zoysiagrass Lawns in New Jersey

Considerable interest has developed in zoysiagrass for home lawns. Advertising, which has stimulated interest in it as the answer to lawn problems, has ranged from fair to misleading. It is not a "miracle" grass as some ads tend to portray. However, zoysiagrass has some distinct advantages that make it useful for lawns in some situations. Test plantings, trials, and observations of zoysiagrass have been made in New Jersey and nearby states for more than 25 years. This fact sheet is designed to summarize present knowledge on the desirability, use, and culture of zoysiagrass. In part, the decision to use or not to use zoysiagrass involves personal preference on its brown winter color. Before purchasing or planting zoysiagrass, become familiar with the characteristics of a zoysiagrass lawn during the different seasons of the year. Consider these advantages and disadvantages before deciding on its use:

Advantages of Zoysiagrass

1. Grows especially well during the hot summer months.
2. Produces a thick, dense, and cushiony turf.
3. Prevents and controls crabgrass and summer weeds because of its thick growth.
4. Has a pleasing green color during the hot summer months when it is more difficult to maintain an attractive appearance of the cool-season grasses.
5. Withstands close mowing (1/2 to 1 inch).
6. Grows in most types of soil with proper management.
7. Withstands wear and tear during the summer.
8. Can survive severe heat stress.
9. Tolerates low fertility once it is established.
10. Requires less water than most cool-season turfgrasses.

Disadvantages of Zoysiagrass

1. Loses its green color and becomes brown and straw colored about mid-October. This color remains until about mid-May of the following spring. In contrast, cool-season grasses usually have good green color for 8 months or longer during the season. Even in mid-winter in New Jersey, cool-season grasses have some green color.
2. Requires vegetative establishment by propagation of stolons or plugs.
3. Establishes slowly. Under ideal conditions, it may cover in one season. Normally, 2 to 3 years are required. When plugged or sprigged into an existing lawn, complete establishment may require 5 or more years.
4. Tends to have more winter annual weed problems than those occurring in cool-season turf.
5. Can be difficult to eliminate, once established, and may be a nuisance around plant beds.
6. May be injured severely, while dormant, from persistent winter traffic.
7. Becomes flammable when brown and straw colored, and may be a fire hazard when allowed to grow tall near wooden buildings.
8. Requires regular mowing in summer for an attractive appearance, because of its tough and dense-growth characteristics.
9. Is subject to rust and fairy ring, but inclined to have less disease than most turfgrasses. Occasionally, summer patch disease has caused serious problems.
10. Does not grow well in shady areas.

Guidelines for Use

Zoysiasgrass is most useful in situations where a summer lawn is of primary importance. The unattractive winter color is not objectionable on lawns of summer homes. This condition may also be acceptable around swimming pools.

Zoysiagrass grows best and is most suitable for the sandy soils of Southern New Jersey. Sometimes, it is used effectively on sunny, south, or southwest slopes, and on poor or sandy soils. Occasionally it is used on curb strips between sidewalks and roads.

Use Winter Hardy Varieties

Some zoysiagrass grown in the southern states may winterkill seriously in New Jersey. The following types which are Zoysia japonica, or are hybrids of this species, have adequate winterhardiness.

'Meyer,' released from Beltsville, Maryland in 1951, has been the most common variety. Vegetative material for propagation is not currently available in New Jersey, but can be purchased from producers in other states.

'Emerald,' was introduced from Beltsville, Maryland in 1955. It has finer leaves than Meyer. This grass appears less hardy than some others, but has survived more than 20 years in New Brunswick.

Japanese lawngrass - Zoysia japonica is somewhat coarser than Meyer.

Establishment and Maintenance

A well-prepared weed-free plant bed is desirable when establishing zoysiasgrass. 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 2 to 4 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 may not become firmly established before winter and, as a result, tend to be susceptible to winter injury.

Plugging - Usual recommendations are to place plugs 2 1/2 inches in diameter (larger than 2 inches preferred) at 8- to 12-inch intervals. Press plugs into a similar size hole to obtain good soil contact. Do NOT cover the plugs with soil or allow the plug to remain elevated. A hard steel plug cutter can be used to cut the plugs in the nursery, and also 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 a wellprepared weed-free plant bed. Sprigs are obtained by tearing apart a piece of sod. Each sprig should be at least 3 inches long and contain one or two nodes. Sprigs are planted with one end below the soil and the other end (with leaf shoots) above the soil. Fresh sprigs are planted 4 to 12 inches apart in rows, and 8 to 12 inches between rows.

Weed Control During Establishment - Summer weeds greatly hinder newly planted zoysiagrass stolons. Several procedures can be used to minimize this problem. On small areas, hand weeding may the quickest and surest method. For larger areas, where weeds are abundant, an herbicide may be desirable. The best one (atrazine) should be used used only by an experienced or a professional applicator.

Several preemergence crabgrass control materials, however, can be used by homeowners. These will control many summer annual weeds.

1. Siduron (TUPERSAN*) at the standard rate for new lawns can control crabgrass.
2. Benefin (BALAN) at the standard rate gives excellent control of a broader range of summer annuals.
3. DCPA (DACTHAL) controls crabgrass effectively, but may cause some injury.

The preceding materials, however, do not control perennial cool-season turfgrasses. Atrazine might be applied by professional applicators to prevent both types of weed problems. This material should be applied accurately at the rate specified on the container for zoysia establishment. Atrazine is available to professional applicators at some farm supply stores.

Siduron, benefin, or atrazine should be applied over sprigs or stolons. Apply any one of these materials immediately, or shortly after planting.

Grassy weeds (such as crabgrass), not controlled at the time stolons are planted, can be treated after germination. Use two or three treatments of DSMA at weekly intervals. If broadleaf weeds are germinating, add 1/2 the normal rate of 2,4-D to one of the DSMA treatments.

Liming - Soil acidity for zoysiagrass should be maintained as for most regular turfgrasses. If a soil test shows that the acidity is below pH 6.0, use the recommended amount of limestone. If the soil pH is 6.0 (or higher) no limestone is needed. Usually about 50 pounds of limestone every 2 to 3 years for each 1000 square feet are sufficient.

Fertilizing - A soil test can provide information for determining the amount and grade of fertilizer needed. At the time zoysiagrass is established on a rototilled or loosened plant bed, apply 20 pounds of 5-10-10 or 10 pounds of 10-6-4 per 1000 square feet. One to 2 weeks after sprig or plug planting, make another application and water in well. During the first season of established sprigs or plugs, repeat the application of fertilizer every 4 to 6 weeks through late August.

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. When fertilizing, apply one pound of actual nitrogen per 1000 square feet of lawn area each time the zoysiagrass is fertilized. Use of fertilizer containing phosphorous and potassium should be based on a soil test.

Mowing - Since zoysiagrass is slow growing, it does not require mowing as frequently in cooler weather as do some turfgrasses. Mowing once a week during this season, however, will help to maintain smooth, wellgroomed turf. It is a tough grass that grows rapidly in hot weather when it may need more frequent mowing. The mowing height should be 1/2 to 1 1/4 inches. Zoysiagrass tends to form a dense mat and is more attractive when mowed low. Low mowing favors this grass and is especially beneficial when trying to get plugs started in established lawns. A close mowing in late April will remove brown leaf tips and encourage earlier greening of a zoysia lawn.

Watering - Newly planted plugs or sprigs of zoysiagrass should be kept moist during the first 2 or 3 weeks to prevent drying. Established zoysiagrass turf does not require as much water as most cool-season lawn grasses. It will survive the early off-color wilt stage, but should be watered when a darker grey-green or loss of green color develops in extended drought periods. A slow application of about 1 inch of water may be needed on established turf during these times.

Chinch bugs, Bill bugs, and Sod Webworms - These insects may cause damage from June through September. Preventive or curative treatments with diazon, dursban (or similar insecticides), when insects are active, should prevent serious damage.

Weed Control - After the lawn is well established, usually there is little need for weed control. Occasionally, a few broadleaf weeds and wild garlic (onion) appear. They can be controlled with the common materials used for coolseason grasses. Combinations of 2,4-D plus dicamba, or 2,4-D plus MCPP, are usually adequate. (Do NOT use under or near trees and shrubs.)

Thatch Control - Thatch—the accumulation of stems, stolons, and roots above the soil surface—is one of the most common problems. Some thatch can be removed with a vertical mowing device or power raking machine. This machine should have a range of adjustments so that the blades can penetrate completely through the thatch layer into the soil. Many so-called dethatching machines, presently available, lack this capability. Therefore, machine selection is important for best results. Remove thatch in mid- to late-spring (usually every year) depending on the amount of fertilizer used. See Rutgers Cooperative Extension publication FS740, "Thatch Management in Turf" for more information on thatch.

Some homeowners have burned their zoysiagrass with fire to eliminate thatch. This practice is not recommended because of the potential fire damage to trees, shrubs, and buildings. Also, environmental laws may prohibit this procedure.

Dyeing the Lawn - Zoysiagrasses, which turn straw colored and brown with the first heavy frost in the fall, can be colored green for the winter months. Several pigmenttype colorants (similar to water-base latex paints) for dyeing brown lawns are available at some garden supply stores. A single application of dye after the zoysiagrass is completely dormant will usually last all winter. Although artificial in appearance, green-dyed lawns may look better to property owners than straw-colored ones.

Another technique is to overseed the lawn with fine-textured perennial ryegrass in mid-September. The lawn must be cut very closely, dethatched, overseeded, and kept moist with frequent light watering. The ryegrasses will germinate quickly and provide green color during the fall and early spring when the zoysia is brown. Suitable, fine-textured ryegrasses include one or more of these varieties: Advent, Affinity, APM, Assure, Birdie II, Brightstar, Charger, Dandy, Delaware Dwarf, Dimension, Elf, Envy, Gettysburg, Legacy, Manhattan II E+, Navajo, Palmer II, Pinnacle, Prelude II, Prizm, Quickstart, Repell II, Saturn, Seville, Sherwood, SR 4000, SR 4100, SR 4200, and Yorktown III.

Elimination of Zoysiagrass

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

If you do not wish to use chemicals, or if complete or rapid 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 cool-season turfgrasses to overtake the zoysiagrass. The process can be hastened by overseeding in the fall with cool-season turfgrasses. Successful overseeding will require close mowing and dethatching of the zoysia in preparation for overseeding.

More rapid eliminaton is possible, but it requires complete chemical eradication. A useful chemical is glyphosate available under different trade names. The material is mixed with water as directed on the container and is sprayed on the zoysiagrass. The treatment is most effective when the zoysiagrass is growing actively in mid-summer. Wait 10 days to 2 weeks and retreat any areas that were missed and/or that show signs of regrowth. Always follow label directions when when using any herbicides.

Before establishing a new lawn, a waiting period of at least 1 week is necessary after the final treatment. If a thick layer of a dead mat (thatch) is present, this layer may be stripped from the soil with a garden spade or sod cutter before attempting to prepare the soil for reestablishing a new lawn from seed or sod. Details on establishing a lawn appear in two references: FS584 "Seeding Your Lawn," and FS108 "Renovating Your Lawn"—available from the Rutgers Cooperative Extension office in your county.

NOTE: This sheet is a revision and replacement of Bulletin E018 "Zoysiagrass Lawns in New Jersey."

December 1993