Turf in the Fall
True to North Carolina, our fall has had a slow, unpredictable start, and that can lead to some confusion about what to do with a lawn.
Mid-September is the best time to sow a cool-season grass, such as tall fescue or Kentucky blue, which will germinate and fill in as warm-season grasses begin to go dormant. Before sowing, aerate the soil to ease compaction and moisten the soil with light irrigation. Sowing cool-season seed in October or later can lead to poor germination and unhealthy grass, but with the temperatures expected to be in the mid- to upper 70s for the next week or two, you can still put seed out and get a decent stand of grass. Most seeding rates are 6 pounds per 1000 square feet, but check the seed labeling for further recommendations. Avoid sowing cool-season grasses in the spring as the weather will warm up too quickly and stress any seedlings that pop up.
At this time of the year, warm-season grasses, such as Bermuda and centipede, require less irrigation, fertilization, and mowing maintenance. As they go dormant, most well-established lawns will do just fine with whatever rainfall occurs. With growth slowing down, you can leave warm-season grasses at a taller height. For example, Bermuda can be left at ½ inch rather than ¾ inch and centipede can be left at 1 ½ inches rather than 1 inch. You should also use a low nitrogen fertilizer heading into fall. Potassium and phosphorus encourage root health and winter hardiness, but nitrogen will encourage a flush of tender new growth that can be nipped by frost and winter temperatures. You should not try to seed, sod, or otherwise establish warm-season grasses at this time as it will be damaged by winter weather.
Whether you are aiming to create a green, healthy winter lawn or summer lawn, you should always take a soil sample! Your soil report will let you know which amendments you need to add and in what quantities; it will also tell you the soil pH and check nutrient values, such as potassium and phosphorus, against the needs of the lawn you are trying to grow. Soil sample kits can be picked up at and returned to your local extension office. Soil samples are usually free until Thanksgiving, at which point at $4 fee will be in place for every sample you submit through April. Following the report recommendations is a major step in creating a thick and healthy lawn!
So, even if the weather is confused, you and your lawn don’t have to be!
Selena McKoy is Horticulture Agent for North Carolina Cooperative Extension in Harnett County.