Zoysia Grass Growth

Establishment

• Only Japanese lawngrass, Zoysia japonica, may be grown from seed. Other species and their cultivars propagate through spreading rhizomes roots and stolon stem nodes that root on the soil surface. Therefore, rather than from seed, these zoysia grass types, called clones, are planted as sprigs, plugs or cut mats of sod. Regardless of what is planted, these grasses grow only when soil and air temperatures are warm.

Seasonal Growth

• In the extreme southern U.S., such as in USDA zones 9 and warmer, zoysia grass remains green and grows year-round. Elsewhere, zoysia grass enters a winter dormancy once temperatures in fall hover in the 32 to 50 degrees Fahrenheit range. While the above-ground leaf blades and stolons cease growth or partially die back in winter cold, the underground rhizomes remain alive as long as soil doesn't become too dry. Once warmth returns in spring, depending on latitude and elevation, the roots and stolons again sprout green leaves. Zoysia grass prosper when temperatures remain between 50 and 100 degrees Fahrenheit.

Growth Habit

• While the roots penetrate deeply to obtain moisture, zoysia grass spreads across the soil as rhizomes sprout new sheaths and stolons reveal new leaves. It grows more slowly in comparison to other warm-season lawns made of Bermuda or St. Augustine grasses. If never mowed, the stiff leaves grow 3 to 6 inches tall with a jagged, rough appearance. Since stolons run across the soil surface in a zoysia grass lawn, gardeners cut it low, 1 to 1 1/2 inches tall to keep the foliage dense and uniform.

Factors Affecting Growth

• Although touted as drought tolerant, zoysia grasses look and perform much better if irrigated during dry spells in the warm growing season months. Richard Duble of Texas A&M University recommends supplementing natural rainfall so 1 to 1 1/2 inches of water reaches the roots each week in midsummer. Zoysia survives on less water, but isn't ideal. Sandy soil drains quickly and needs more frequent irrigation than loam or clay soils. Applications of nitrogen-rich fertilizer also increases leaf growth and ensures the deepest green color. A moderate rate of 1 lb. of nitrogen per 1,000 square feet suffices. Fertilizing occurs only from late spring to fall.