Bermuda grass is a warm-season turf prized for its durability and vibrant color during the summer. This green appearance is temporary, as the grass enters dormancy when cooler weather arrives. Dormancy is a natural survival mechanism triggered when soil temperatures consistently drop below 55°F. This causes the plant to stop producing chlorophyll, turning the blades a uniform tan or brown. To maintain a green aesthetic year-round, homeowners can either introduce a temporary cool-season grass or apply a specialized colorant.
Maximizing Color Retention Before Dormancy
Preparing a Bermuda lawn in the fall can delay browning and improve the grass’s health for winter survival. This preparation focuses on building internal reserves and fortifying the plant against cold stress. Adjusting the mowing practice is a crucial step, involving gradually lowering the cutting height toward the end of the growing season. This opens the turf canopy, allowing sunlight to reach the crown and encouraging the storage of carbohydrates in the root system.
The late-season fertilization strategy must shift away from high-nitrogen formulas, which promote tender leaf growth susceptible to cold damage. Instead, a final application of a fertilizer high in potassium, often called a “winterizer,” is beneficial. Potassium enhances the plant’s winter hardiness, drought tolerance, and disease resistance. This application should occur approximately four to six weeks before the first expected frost date.
Avoiding excessive moisture is also an important cultural practice to minimize the risk of winter injury. Ensuring the lawn has proper drainage and avoiding late-day watering reduces the chance of frost damage to the plant’s crown. These practices ensure the turf is in the best condition to survive winter and green up quickly when warm temperatures return.
The Overseeding Method
Overseeding is a traditional solution involving planting a cool-season grass on top of the dormant Bermuda turf to provide green coverage through the winter. This process typically uses ryegrass, which grows actively when Bermuda is resting. Overseeding begins when soil temperatures fall to around 70°F, usually in mid-September or mid-October. Preparation requires “scalping” the Bermuda grass by mowing it down to one inch or less. This removes excess leaf material and ensures the new seed makes direct contact with the soil.
The choice of seed is usually between annual or perennial ryegrass. Perennial ryegrass offers a darker green color and finer texture, and is often preferred for its appearance and durability. However, perennial varieties require specific management to eliminate them in the spring. Seeding rates commonly range from 10 to 15 pounds per 1,000 square feet for a dense winter lawn.
After spreading the seed evenly, water lightly multiple times a day to keep the seeds consistently moist until germination occurs. Germination can happen quickly, sometimes within three days for annual ryegrass. Once established, a light application of a starter fertilizer helps the ryegrass thrive during cooler months. The main challenge with this method is the competition the ryegrass creates when the Bermuda grass attempts to emerge from dormancy in the spring.
Applying Turf Colorants
A modern alternative to overseeding is the application of specialized turf colorants, which are non-toxic, biodegradable green dyes or paints. These colorants instantly change the appearance of the dormant, brown grass blades to a natural-looking green. Colorants designed for dormant grass are often called “paints” and contain a higher concentration of binding agents. This ensures the color adheres to the non-growing leaf blades for an extended period.
These specialized products are applied using a pump sprayer and are formulated to be safe for the environment and the underlying Bermuda grass. The application technique focuses on achieving uniform coverage while avoiding overspray onto sidewalks or other hard surfaces, as the product is designed to stain. Unlike overseeding, this method requires no water for establishment and creates no competition for the warm-season grass in the spring.
The longevity of the colorant depends on the growth of the grass, the frequency of mowing, and the amount of foot traffic. A single application can last for up to three months. Turf paint is gradually worn or mowed off, so reapplication is necessary only when the color begins to fade. This approach reduces winter water usage and, by darkening the turf, may slightly increase soil temperature, potentially promoting an earlier spring green-up.
Winter Maintenance and Spring Transition
Regardless of the method chosen, maintenance during the cold season must account for the dormant Bermuda grass below. Once the Bermuda is fully dormant, the need for irrigation is significantly reduced. The lawn requires only about one inch of water every four weeks if natural rainfall is insufficient. It is also advisable to minimize foot traffic on any frozen turf to prevent damage to the brittle, dormant grass blades.
The spring transition is the most delicate period for an overseeded lawn, as the ryegrass must be removed to allow the Bermuda grass to thrive. The transition process should begin when nighttime temperatures consistently exceed 65°F, signaling the Bermuda’s readiness to emerge. This involves gradually reducing irrigation to stress the cool-season ryegrass while providing enough moisture to support the recovering Bermuda.
The overseeded lawn must be mowed low and frequently. This removes the shade-creating ryegrass canopy and allows sunlight to reach the Bermuda underneath. A light application of nitrogen fertilizer encourages the Bermuda grass to grow aggressively and hastens the death of the heat-stressed ryegrass. For lawns colored with turf paint, the transition is simpler; the paint naturally fades and is slowly removed by mowing as the new Bermuda blades emerge.