Figure 1
Use a long-handled bulb planter, or plugger, to
remove soil cores before planting zoysiagrass plugs.
Figure 2
Place zoysiagrass plugs in holes 6 to 12 inches apart in a diagonal grid pattern.
Figure 3
Press the plugs into the holes by foot or by light
tamping or rolling to ensure good contact with the soil.
Establishment and Care of Zoysia Lawns
Brad S. Fresenburg
Division of Plant Sciences
Zoysiagrass was introduced into the United States from Korea about 1900.
A Zoysia japonica seedling with improved winter hardiness was selected
from early plant collections and was released in 1951 under the name 'Meyer'.
This variety has better low-temperature tolerance than most other zoysiagrass
varieties and is still the best choice for the Midwest transition zone. Zoysiagrass
is adapted to the southern two-thirds of Missouri, where it is used primarily
for home lawns or golf courses where a dense, low-cut turf is desired.
Zoysiagrass is a warm-season grass that spreads by both rhizomes and stolons.
Stems and leaves are tough and stiff. It requires only occasional irrigation
and may give excellent-quality turf from mid-May through mid-September. Although
zoysiagrass is a good choice for hot weather, it goes dormant as soon as fall
frosts arrive and stays brown until weather warms in spring.
Zoysiagrass grows best in full sun and requires at
least six to eight hours of sunlight. It will tolerate
moderate shade, but the turf will be thinner and less
competitive in shady areas. Zoysiagrass requires
less supplemental irrigation and fertilization than most other turfgrasses.
It grows best when maintained with low to moderate nitrogen fertilization. Established
zoysiagrass competes well with weeds and other turfgrasses.
Establishment
Zoysiagrass lawns generally are established vegetatively with plugs (small cores
of sod), sprigs (stolon or rhizome sections), sod or strips of sod. Zoysiagrass
can also be established by seed. However, the varieties that are currently available
often display variable leaf width, color and require further evaluation in the
Midwest for winter hardiness. The best time to vegetatively establish a zoysiagrass
lawn is during late spring to early summer. Late-summer (mid-August) plantings
may not allow sufficient time for complete establishment making turf more susceptible
to winter injury. Plugs and sprigs should be planted between late April and June.
Sod can be laid as late as September as long as temperatures are warm enough
for the sod to root into the soil.
Soil preparation
Proper soil preparation will lead to successful establishment and easier care
of your lawn during succeeding growing seasons. Twelve steps for zoysiagrass
establishment are listed below. These steps may not all be required to successfully
establish your lawn. For example, soil need not be completely tilled where grading
and soil amendments are not required and when soils are not excessively compacted.
- Obtain a soil test and get fertilizer/limestone recommendations. Contact
your local MU Extension center.
- Rough grade
- Apply lime, if needed
- Apply fertilizer as recommended by soil test
- Apply soil organic amendments if needed (such as peatmoss or compost)
- Till in above materials 4-6 inches deep
- Finish grade
- Apply starter fertilizer and work into top inch of soil
- Install sod, plugs or sprigs
- Water
- Mow
- Control weeds
Sodding
While sodding is the most expensive method of zoysiagrass establishment, it
does result in an "instant" turf. Although several weeks are required before
a newly sodded turf can withstand traffic or play, sodding does provide an established
turf cover. For this reason, it is often the preferred method of planting on
erosion-prone sites.
Sodbeds should be moist, but not wet, at the time of sodding. If soil is
excessively dry, especially under high temperatures, rooting may be poor regardless
of subsequent irrigation practices. Sod should be laid so that the ends of adjacent
strips are staggered. Individual strips should be fitted firmly against adjacent
strips and lightly tamped or rolled to provide uniform contact with the soil.
When laid on sloping terrain, sod strips should be secured in place with stakes
until rooting is sufficient to stabilize the sod.
Strip sodding
Strip sodding is a variation of complete
sodding in which sod strips 6 to 12 inches wide are laid 1 to 2 feet apart and
allowed to spread together. Strip sodding is less expensive than sodding, but
the turf must be managed properly to achieve full coverage in a reasonable amount
of time.
Plugging
Plugs are small pieces of sod, two or more inches wide with 2 to 3 inches of
soil and roots.
| Plug spacing |
Number of plugs per 1,000 square feet |
Yards of sod required for plugs1 |
| 6 inches |
4,000 |
12+ |
| 8 inches |
2,250 |
7 |
| 12 inches |
1,000 |
3+ |
1Based on 2-inch plugs, 1 sq. yd. of sod = 324 plugs.
A specially designed tool called a plugger or a long-handled bulb planter
should be used to remove cores of soil the same size as the zoysiagrass sod
plugs. This will make planting easier and ensure better soil contact with the
plug. A starter fertilizer, such as 8 pounds of 12-12-12 per 1,000 square feet,
may be raked into the upper inch of bare soil before planting. The plugs should
be kept moist before they are dropped into the holes. They are inserted into
the soil, usually at 6- to 12-inch spacing, so that the tops of the plugs are
flush with the soil surface. Closer spacing will give more rapid coverage. Plugs
may be pressed firmly into the holes with the foot or lightly tamped or rolled
after planting to ensure good soil contact. With no competition from other grasses,
expect two growing seasons for complete coverage.
Keeping plugs moist for the first two or three weeks after planting is essential
to prevent the roots from drying out.
Sprigging
The term "sprig" refers to a portion of the zoysiagrass plant that includes
a short piece of the stolon or rhizome, roots and leaves, but not soil. Sprigging
is less expensive than plugging and may give a faster rate of cover. However,
sprigs require more initial and post-planting care than do plugs and are less
likely to survive under adverse conditions.
The individual sprigs may be purchased from nurseries or separated from pieces
of sod. Approximately 2 to 3 square yards of mature zoysiagrass sod will be
needed to sprig 1,000 square feet of lawn surface. Late spring is the best time
for planting sprigs. A starter fertilizer may be applied before sprigging.
Plant the sprigs in rows about six inches apart. Narrow furrows, 2 or 3 inches
deep, can be made with a sharp spade or hoe. Do not let the sprigs dry out during
planting. When planted in the furrow, one end of the sprig should be at least
2 inches below the surface of the ground, but part of each sprig must be above
the ground. The furrow may be closed with a light roller or by walking on it
to ensure good soil contact.
An alternative to planting sprigs in rows is to simply broadcast the sprigs
onto a prepared bed. Water frequently (as many as 3 or 4 times a day) to prevent
sprigs from drying out. A straw mulch (1 bale per 1,000 square feet) will also help prevent
drying.
Converting an existing lawn to zoysiagrass
Plugging and strip sodding can be used not only in planting zoysiagrass in bare
soil, but in introducing it into an existing turf. For example, a Kentucky bluegrass
lawn can be converted to zoysiagrass by planting plugs into the bluegrass turf.
The conversion process is usually slow, but it can be accelerated by adjusting
cultural practices to favor the zoysiagrass. Keep the lawn mowed short (1 inch)
to help the zoysiagrass spread. Fertilize on a schedule (May to August) to favor
the zoysiagrass. Apply light applications of nitrogen fertilizer (about 1 pound
of nitrogen per 1,000 square feet) every four weeks during the active growing
season. It will take two to five years for the zoysiagrass to take over under
normal circumstances. Excessive fertilization and irrigation will increase competition
of existing grasses and will slow the spread of zoysiagrass.
Under most conditions, sprigging into an existing lawn is generally not as
successful as plugging due to competition from the existing grass. Therefore,
the planting area is prepared by killing the existing sod or weeds with a nonresidual
herbicide, such as glyphosate or glyfosinate-ammonium, and sprigged five to
seven days later. This procedure will also speed establishment by plugging or
strip sodding.
Maintaining a zoysiagrass lawn
Fertilizing
Established zoysiagrass requires less fertilizer than many other species for
healthy, attractive turf. A seasonal total of 2 pounds of nitrogen per 1,000
square feet is ample. Excessive or untimely fertilizer applications can lead
to problems such as fewer roots, more thatch, diseases, and more topgrowth that
requires increased mowing.
For best results, soil testing is recommended before fertilizing. A soil
test will indicate major nutrient deficiencies and the acidity or alkalinity
(pH) of the soil. Slightly acidic soil pH (6.0-6.5) is best. Lime should be
applied only if the pH is less than 6.0.
Established zoysiagrass should be fertilized from May through August. Early
spring (March/April) fertilization benefits weeds and promotes premature topgrowth
before roots begin to grow. Late fertilization (September) may interfere with
the natural hardening process before winter.
For routine maintenance where soil tests indicate no major deficiencies,
use a lawn fertilizer with approximate nitrogen (N):phosphorus (P):potassium
(K) ratio of 3:1:1 or 4:1:1 or 4:1:2. A 16-4-8 fertilizer has a 4:1:2 N:P:K
ratio.
Where soil test indicates low phosphorus or potassium levels or where basic
fertility levels are not known, use a fertilizer with a ratio that more closely
approximates 1:1:1 or 2:1:1.
Mowing
Zoysiagrass is mowed at a shorter cutting height (1-2 inches) than Kentucky bluegrass
or fescue. In the spring of the year, zoysiagrass lawns may be mowed at the lowest
setting on your mower to remove dead leaf tissue. This increases the greenup
rate and allows easier and more uniform mowing during the growing season. The
mowing height should be raised in September by 1/2 to 1 inch in preparation for
fall.
When mowing, never remove more than one-third of the leaf blade at any one
time. Clippings need not be collected if they do not remain as clumps on the
lawn surface.
Watering
Zoysiagrass is a drought-tolerant lawn grass that requires less water than Kentucky
bluegrass to remain green and actively growing during the summer months. Watering
usually is not necessary except during prolonged dry periods.
Cultural practices, such as proper fertilizing, mowing and thatch control,
can go a long way toward building a drought-tolerant lawn.
When watering, follow these simple rules.
- Water in early morning to reduce
disease incidence
- Water deeply, wetting the soil to a depth of 4 to 6 inches.
Thatch
Thatch is a layer of decomposed and partially decomposed roots, stems, stolons
and rhizomes. Thatch appears as a distinct horizontal layer of brown spongy or
feltlike material just above the soil surface. Zoysiagrass is prone to thatch
accumulation because of its thick network of rhizomes and stolons and coarse,
tough stem tissue. When managed properly, clippings returned to a zoysiagrass
lawn contribute little, if any, to the thatch layer.
Lawns should be dethatched when thatch exceeds 1/2 inch in thickness. A spring-tine
power rake or vertical mower will accomplish this task.
If thatch is greater than one inch, do not attempt complete removal in one
year. Instead, remove the thatch over a period of two or three years. Intensive
coring should also be considered since this causes much less damage to the turf
than does power raking or vertical mowing.
Thatch buildup can be minimized through good cultural practices, including
the following:
- Fertilize moderately to maintain turf density without excessive growth
- Cut grass regularly at the recommended height to maintain vigor and to avoid
shock. Clippings may be left to decompose if mowing occurs at regular intervals.
No more than one-third of the leaf tissue should be removed with each mowing.
Remove excessive clippings that accumulate in clumps on the surface
- Water deeply and only as needed
- Power rake or vertical mow with dethatching equipment as needed to keep
thatch less than 1/2 inch thick. For zoysiagrass, early summer after the lawn
has greened up is the best time to dethatch
- Where lawns are subjected to traffic, core aerify to improve penetration
of water and fertilizer. Leave soil cores on the surface to dry and crumble
before mowing
Weed control
A properly managed zoysiagrass lawn is very competitive with weeds. However,
winter annuals, such as chickweed and henbit, can be a problem when the grass
is dormant. Weeds will also invade turf after it has been damaged or weakened
by insects, disease or intense dethatching.
Winter annual weeds are best controlled in the fall rather than the spring,
when they bloom and set seed.
Grassy weeds, such as crabgrass, generally are not a problem in established
zoysiagrass lawns. An early spring application of a crabgrass preventer may
be desired while new lawns are being established or on close-mowed or regularly
irrigated turf.
Insect and disease control
In general, zoysiagrass has few insect or disease problems. White grubs and billbug
are the primary insect problems. Early detection and proper timing of insecticide
applications is essential in preventing serious damage.
Zoysiagrass is not especially susceptible to disease, however, some diseases
do appear in zoysiagrass lawns. Diseases usually can be avoided through proper
cultural practices, especially mowing, fertilizing, watering and thatch control.
G6706, reviewed March 2005