Zoysia grass is a popular warm-season turfgrass known for its dense growth and soft texture, particularly favored in the southern United States and the transition zone. As a warm-season variety, its active growth cycle is dependent on high temperatures. Understanding the plant’s response to winter is necessary for homeowners who want to maintain a healthy lawn. The grass does not perish in the cold but instead employs a natural survival strategy to endure the winter months.
The Mechanism of Zoysia Dormancy
Zoysia grass does enter a state of dormancy in winter, which is a normal, biological process for warm-season grasses. This survival mechanism is triggered when sustained soil temperatures fall below a specific threshold, typically around 55°F. Once the soil temperature drops, the plant ceases producing chlorophyll and stops its above-ground growth, conserving energy in its root system.
The slowing of growth is a proactive defense against freezing temperatures. The plant efficiently channels its energy and nutrients down into the rhizomes and stolons beneath the soil surface. Dormancy is essentially a prolonged period of rest, ensuring the grass has the energy reserves needed for a strong recovery when warm conditions return.
The Appearance of a Dormant Lawn
The most noticeable consequence of Zoysia dormancy is a dramatic change in its visual appearance. The grass blades lose their vibrant green color because the production of chlorophyll has stopped. This results in the lawn turning a uniform tan or straw-brown color.
This light-brown hue is a normal, temporary state and does not signify that the grass is dead. The dormant blades offer a layer of insulation, helping to protect the living crowns and roots from extreme cold. The roots remain firm and anchored, ready to resume growth in spring.
Essential Winter Preparation and Care
Proper preparation in the fall is necessary to ensure the Zoysia lawn successfully navigates dormancy. The grass should receive its final mowing at its normal height, generally between 1 to 1.5 inches, right before the onset of dormancy. It is beneficial to apply a fall fertilizer that is low in nitrogen but higher in potassium, sometimes called a winterizer, to enhance the grass’s cold tolerance and root health.
Though the grass is not actively growing, limit foot traffic on the dormant lawn, as the brittle, frozen blades are susceptible to breakage and damage. The deep root system of established Zoysia typically does not require winter watering; however, in periods of severe drought or high winds, a light watering may be needed to prevent the roots from drying out entirely.
The Spring Transition
The process of exiting dormancy is directly tied to the return of consistent warmth. Zoysia requires soil temperatures to remain reliably warm, typically in the range of 60°F to 70°F, to signal the resumption of growth. This temperature trigger often means Zoysia is one of the last warm-season grasses to fully green up in the spring.
As the soil warms, the plant begins to produce chlorophyll again, and the blades transition from brown to green. Homeowners can encourage a faster green-up by mowing the turf low in early spring, which helps remove the dead, brown winter growth. Once the lawn is fully green, a balanced spring fertilizer application will support the new season of active growth.