Zoysia plugs may be planted as long as the soil temperatures are at or above 40 F. This condition varies by region, as elevation and latitude determines the climatic regime during any cold months, fall through early spring.
Even though the zoysia plugs may remain dormant and look tan after planting in a cold month, it's important to maintain an evenly moist soil so the roots do not dry out and die. Supplement rainfall as needed to keep soil moist, but never soggy. Applying a pre-emergent herbicide diminishes infestation of cool-season weeds across the plugged lawn.
For best growth and establishment of a zoysia grass lawn, withhold planting the plugs until the warmer months. When soil and air temperatures are warm from late spring to early fall, the roots grow into the soil and establish before the onset of cold weather and dormancy. With deeper-spreading roots, there is less chance of dry soil in winter causing plant death.