What happens
Zoysia grows best at 80 to 95 °F, turns brown with the first autumn frost and stays dormant through winter (Clemson). Its crowns and rhizomes survive; the leaves do not. Zoysia is among the first warm-season grasses to brown and the last to green.
Autumn
- Stop nitrogen early. Clemson: last application at least six weeks before the first frost. UGA: last nitrogen in August; later feeding can delay dormancy and raise cold-injury risk.
- Feed potassium. NC State puts 1 pound of K2O per 1,000 square feet in September to November. Clemson notes potassium supports cold hardiness.
- Keep watering to about 1 inch a week if it does not rain, while the grass is still growing (UGA).
- Lime if your soil test says so; fall is a good time (UGA).
- Pre-emergent for winter weeds (NC State).
- Rake leaves so they do not smother the crowns.
Winter
No mowing. Pick up sticks and rocks. Water only if the soil is powder dry (NC State). Keep heavy traffic off frozen turf. Test the soil every three years.
Overseeding for green
UGA says overseeding zoysia with ryegrass is not recommended. Ryegrass is still growing as the zoysia wakes up, so it can slow green-up and leave the zoysia thinner. If a green winter lawn is essential, bermudagrass is easier to overseed; see Bermuda or zoysia.
Spring green-up
Wait for warm soil. UGA advises no spring nitrogen until the soil at 4 inches is steadily 65 °F and rising; NC State feeds about three weeks after green-up. Mow low at green-up but do not scalp. Slow green-up after a hard winter, a cold wet spring or a late-autumn feed is common; give it time before you decide it died. Check crowns: green at the base means alive.
Cold-hardiness check
If winters near you are harsh, choose a hardy cultivar. Emerald, for instance, is reported to suffer winter injury north of Columbia, South Carolina (Clemson). See the cultivar chooser.