If you find circular roots, take a clean, sharp knife and cut an inch off the sides of the rootball all the way around. Place the plant and its reduced rootball in the same container and add new soil. If the roots are not tightly wound but a larger pot will soon be in order, rough the roots up to discourage circular growth and repot in the next size container. Other factors interfere with nutrition and plant efficiency, too. Nematodes, on less frequent occasions, and phosphorus build up, which creates toxic conditions.
Zoysia is a perennial warm-season grass that tolerates wear and makes a most attractive lawn.
Zoysia is moderately shade tolerant and, thanks to a deep root system, drought-tolerant when established. It will turn a straw color if not irrigated during a drought, but responds to watering or rain. It browns after a freeze but is among the first of the warm-season turfgrasses to green in spring. This grass tolerates various soil types and alkaline or acidic conditions, but needs good drainage. Apply a nitrogen fertilizer in spring, early summer and fall for a dense, green turf.