Lawn care calendar for Georgia: when to fertilize and seed

Dates shift with the weather; follow the signs in the text.

Which grasses grow where in Georgia

UGA lists bermudagrass, zoysiagrass and centipedegrass as adapted statewide, and St. Augustinegrass for the Coastal Plain. Tall fescue is the cool-season option, and Kentucky bluegrass also has a UGA calendar. Warm-season grasses grow best at 80 to 95 F and turn brown and dormant in winter, while cool-season grasses grow best at 60 to 75 F and may struggle in summer.

Each grass has its own rules. Centipedegrass wants only 1 to 2 pounds of nitrogen a year and 1 to 2 inches of mowing height. St. Augustinegrass cannot be grown from seed and takes sod. Bermudagrass and St. Augustinegrass take 2 to 5 pounds of nitrogen a year, and zoysiagrass 2 to 3 on its calendar, though the species page says 2 to 5.

Frost dates from NOAA

Dates are the NOAA 1991-2020 normals for the last spring and first fall 32 F freeze at 50% probability. At Atlanta Hartsfield-Jackson the average last spring frost is March 15 and the average first fall frost is November 20. At Athens (Ben Epps Airport) the dates are March 23 and November 10. At Macon (Middle Georgia Regional Airport) they are March 21 and November 10, and at Albany (Southwest Georgia Regional Airport) March 8 and November 21.

Albany is the southernmost of these four stations, and its last spring frost comes a week before Atlanta's on these averages (computed from the dates).

Spring

UGA says not to apply nitrogen in spring until the soil at 4 inches is steadily 65 F and rising, which is why the feeding window opens in April or May and not at the first warm day. Crabgrass preventer is a different matter: February and March are the best months, with April possible.

Mowing begins in April for bermudagrass, zoysiagrass and St. Augustinegrass. Mow bermudagrass at 1 to 2 inches and hybrids at 1 to 1.5 inches, zoysiagrass at 1 to 2 inches, St. Augustinegrass at 2 to 3 inches and centipedegrass at 1 to 2 inches, and raise the blade a half inch in hot weather.

Summer

Summer is the main season for warm-season lawns. Feeding is best from May to August, aeration from May to August, and dethatching in June and July when thatch is over a half inch. Grassy weeds such as crabgrass can be treated after they emerge, from May to August, but not on drought-stressed grass.

Water about 1 inch a week if there is no rain. Tall fescue needs more help: keep it at 2 to 3 inches, raise the mower in the heat and feed only in the cool months.

Fall

Fall splits by grass. Tall fescue is seeded at 5 to 6 pounds per 1,000 square feet and does best in October, when seeding, interseeding, sodding, aeration and feeding all peak. Do not apply winter preventer if you plan to seed, interseed or sod within 3 to 4 months.

Bermudagrass can be overseeded with 5 to 10 pounds of ryegrass per 1,000 square feet, best in October. UGA does not recommend overseeding zoysiagrass or centipedegrass with ryegrass. For winter weeds such as chickweed, September is the best month for a preventer.

UGA Extension and soil testing

UGA Extension publishes the lawn calendars biennially in its Turfgrass Pest Control Recommendations for Professionals, and each calendar says to follow the fertilizer advice on a soil test report. Bermudagrass and tall fescue like a pH of 5.5 to 6.5, zoysiagrass 6.0 to 7.0 and centipedegrass 5.0 to 6.0, and lime can go on any month.

Soil, plant tissue and water testing is offered through county Extension offices in Georgia, and availability varies by county, so ask your local office.