The timing for applying “weed and feed” in North Carolina depends entirely on the type of grass you have and your location within the state. This combined lawn care product, which contains both fertilizer and an herbicide, is a convenient way to nourish turf while preventing or killing weeds simultaneously. Because North Carolina covers a wide range of climates, no single schedule works for every lawn. The precise moment of application must align with the active growth cycle of the specific grass type and the germination temperatures of target weeds.
Understanding NC’s Climate Zones and Turf Types
North Carolina’s geography creates three distinct climate zones that influence which type of grass thrives. The Mountain region, with cooler temperatures, is best suited for cool-season grasses, which grow actively during the spring and fall. The Coastal Plain region, with hot and humid summers, is home to warm-season grasses. The central Piedmont region acts as a transitional zone where both cool-season and warm-season grasses are commonly grown.
Cool-season grasses (Tall Fescue, Kentucky Bluegrass, and Perennial Ryegrass) grow best when temperatures are between 60°F and 75°F. Warm-season grasses (Bermuda, Zoysia, Centipede, and St. Augustine) thrive in temperatures ranging from 80°F to 95°F. Application timing must follow the grass type’s biological clock, which is primarily dictated by soil temperature.
The Timing for Cool-Season Grasses
Cool-season turf, such as Tall Fescue, primarily found in the Piedmont and Mountain regions, has two main periods for weed and feed application. The most important application window occurs in the fall, which is when the grass is building root reserves for the winter.
The fall application should occur around early to mid-September, when soil temperatures begin to drop below 70°F. This timing is critical because it coincides with the optimal window for applying a granular fertilizer high in phosphorus and potassium to encourage deep root growth. Applying a pre-emergent herbicide targets winter weeds like Poa annua before they germinate.
The second, lighter application occurs in late winter or early spring to provide a small boost as the grass exits dormancy. This spring application should be timed for late February to early March, before the soil temperature consistently reaches 55°F. This temperature triggers the germination of summer weeds, such as crabgrass, making the pre-emergent herbicide treatment highly effective.
Applying a light, slow-release nitrogen fertilizer during this early spring window promotes a healthy green-up without causing excessive top growth that could be susceptible to summer heat stress. Avoid heavy nitrogen feeding in the late spring or summer, as this can weaken the grass and increase its susceptibility to disease. For Tall Fescue, the primary focus for nutrient and weed control remains the fall application.
The Timing for Warm-Season Grasses
Warm-season turf, common in the Coastal Plain and Southern Piedmont, follows an inverted application schedule compared to cool-season varieties. These grasses, including Bermuda and Zoysia, are dormant during the winter and only begin active growth when temperatures rise.
The main application window, combining fertilizer and pre-emergent weed control, should take place in the spring as the grass begins to emerge from dormancy. This window is typically late April or early May, when the lawn is about 50% green and the soil temperature has consistently reached 65°F. The 65°F soil temperature is the threshold that triggers the germination of summer annual weeds, making it the ideal moment for the pre-emergent barrier.
Subsequent light feedings are beneficial during the peak growing season, spanning from late spring through mid-summer. Applying a balanced nitrogen-heavy fertilizer in June and July supports the aggressive growth phase of warm-season grasses. These mid-summer feedings help maintain the dense, green appearance.
The final application of the year should occur in late August to early September, serving as a preparation for dormancy. This application should be a light, low-nitrogen fertilizer that focuses on potassium to enhance cold hardiness and root health. Avoiding nitrogen after early fall is important, as it could stimulate tender new growth that would be damaged by the first frost.