Zoysiagrass is a warm-season grass that spreads by rhizomes and stolons to produce a very dense, wear-resistant turf. It is best adapted to the Piedmont and Coastal Plain regions of North Carolina, but some of the more cold tolerant cultivars can be grown in the western part of the state as well. There are three major species of zoysiagrass suitable for turf: Japanese lawn grass (Z. japonica), mascarene grass (Z. tenuifolia), and manilagrass (Z. matrella). Zoysiagrass can often be confused with bermudagrass. However, zoysiagrass has hairs standing upright on the leaf blade whereas bermudagrass does not. Zoysiagrass is also stiff to the touch and offers more resistance than bermudagrass.
Warm-season grasses include Bermudagrass, St. Augustinegrass, centipedegrass, zoysiagrass, bahiagrass and carpetgrass. They are often called southern grasses because they grow best in hot summer areas and lack the winter hardiness of the cool-season grasses. Depending on location, warm-season grasses grow vigorously from mid- to late spring through summer and into early fall. They usually turn brown and go dormant in winter.
The most important time to feed Zoysia lawns is from spring through summer and, in some southernmost areas, into fall. It should not be fertilized prior to active growth in spring (wait until you have mowed the lawn twice) or late into the fall (six weeks prior to the average date of the first frost). Either practice can weaken the turf and lessen hardiness.
Fortunately, zoysia grass isn’t bothered by too many insects. If they do become a problem, you will find that the white grub is generally the most damaging. White grubs are the larva of the June beetle and feed on the grass at the soil level. Evidence of white grub damage is when the grass appears cut at the soil line and in worst cases can actually be lifted up like a carpet. Large sections of the lawn can be damaged.
In terms of diseases, Brown patch is probably the most damaging disease. Rust and leaf spot can also cause problems, but they are usually not too serious.
Brown patch occurs in the hot, humid, wet periods of summer. It begins as a 1 foot wide patch and can enlarge to several feet in diameter. The lesions that appear on the grass become tan in appearance as the grass tissue dries out. Webby mycelium can be seen along the outer edges of the damaged area on damp mornings.
It is important to avoid applications of nitrogen fertilizer as well as weed control products when the disease is present. It will only feed the fungus.