Zoysia grass is a popular warm-season turf valued for creating a dense, carpet-like lawn that handles heat and moderate traffic well. Like other grasses adapted to warmer climates, Zoysia goes dormant in winter. This is a natural, protective state that allows the plant to survive colder conditions. This process is not a sign of the grass dying, but rather a temporary pause in growth, ensuring the roots and crowns remain healthy until favorable weather returns.
Understanding Zoysia’s Dormancy Cycle
Zoysia is classified as a warm-season grass, meaning its active growth period occurs during the high temperatures of late spring and summer. The primary trigger for Zoysia to enter its dormant state is sustained cool soil and air temperatures, typically falling below 55°F (13°C). This physiological change is the plant’s way of conserving energy and protecting itself from cold damage.
During dormancy, the grass redirects its energy reserves, primarily carbohydrates, from the leaf blades down to the protected root system and the crown, which is the base of the plant. The length of this dormant period can vary significantly based on location, lasting only a month or two in warmer zones but potentially up to four months in cooler transition zones.
It is important to differentiate this winter dormancy from the temporary dormancy caused by drought or extreme heat during the summer. While both result in browning, heat-induced dormancy is rapidly reversible once moisture is reintroduced. Winter dormancy, conversely, is triggered by temperature and requires a sustained increase in both air and soil warmth to reverse the process.
Visual Indicators of Dormancy
The most noticeable sign that Zoysia grass has entered winter dormancy is a dramatic change in its appearance. The vibrant green color that characterizes the lawn during the growing season fades and transitions to a tan or straw-brown hue. This color change is a normal and expected part of the cycle, indicating that the grass has successfully shut down its above-ground growth.
The texture of the lawn also changes, becoming much stiffer and more brittle. A patchy appearance, where some areas remain green while others have turned brown, can occasionally occur during the transition period due to microclimates or inconsistent temperature exposure. The appearance of the lawn in this state should not be mistaken for a disease or a sign of poor health. The life of the plant remains stored below the surface in the roots and crown.
Essential Care During Winter Dormancy
Though Zoysia grass halts active growth during winter, a minimal level of maintenance is still beneficial to protect the dormant turf. Mowing is generally suspended entirely because the grass is not growing, but a final cut before dormancy sets in is recommended to keep the height between 1 to 2 inches. This height helps shield the crowns of the grass without inviting snow mold or other diseases.
Watering requirements are significantly reduced, but the grass still needs some moisture, particularly in dry winter climates. For established lawns, the deep root system can often access moisture in the soil, but in the absence of rain or snow, a deep watering every two weeks may be necessary to prevent desiccation. This minimal watering should be done early in the day to allow the moisture to absorb before potential night-time freezing.
The application of nitrogen fertilizer should be avoided entirely during the dormant period, as it would encourage new, tender growth that is highly vulnerable to frost damage. Instead, any necessary winterizing fertilization, often high in potassium, should be applied in the late fall before the grass enters dormancy to enhance cold hardiness.
A dormant Zoysia lawn is particularly vulnerable to physical stress because the leaf blades are brittle and the crowns are inactive. Heavy foot traffic, vehicle pressure, or excessive activity should be minimized to avoid damaging the dormant plant tissue. Damage to the crown during this time can create entry points for disease or result in bare patches that are slow to recover in the spring.
Spring Transition and Regreening
The process of Zoysia grass exiting dormancy and beginning to regreen is triggered by a sustained increase in temperature. Regreening typically begins when soil temperatures consistently rise back into the 60–65°F (15–18°C) range. This temperature threshold signals to the plant that the threat of deep freezing has passed, allowing it to resume metabolic activity.
The transition from a straw-brown lawn back to a vibrant green is often gradual and can take several weeks, resulting in a patchy appearance initially. Depending on the climate and local weather patterns, Zoysia may begin to show signs of life earlier than other warm-season varieties, sometimes as soon as soil temperatures reach 50°F (10°C). However, the process can sometimes be reversed temporarily by a late-season frost, causing the emerging green tips to brown again.
Once the grass begins to show consistent signs of new growth, post-dormancy care can begin, including a light initial mowing to remove the dead winter growth. It is important to wait until the lawn is fully green and actively growing before applying any nitrogen-based spring fertilizer. Fertilizing too early, while the roots are still sluggish, can promote weed growth instead of turf growth.