Lawn care calendar for Mississippi: when to fertilize and seed

Dates are from MSU Table 9 (feeding) and Table 5 (planting) for hybrid bermudagrass unless a row names another grass; MSU says the chart leaves out optional winterizing feedings.

Which grasses grow where in Mississippi

MSU Extension divides lawn grasses into warm-season types, which grow best above 80 F, and cool-season types, which prefer 60 to 75 F. Bermudagrass adapts to all of Mississippi, and the other lawn grasses it lists are St. Augustinegrass, centipedegrass, zoysiagrass, carpetgrass and bahiagrass. St. Augustinegrass is the most cold-sensitive and is a popular choice in south and central Mississippi.

Only the northern tier of counties can grow tall fescue, Kentucky bluegrass and creeping red fescue as permanent lawns. MSU calls zone 7a a place where either type can work, with the choice between a warm-season grass that may be winter-killed in a severe winter and a cool-season grass that must be nurtured through the summer. Annual and perennial ryegrass are for winter lawns and are not permanent lawn grasses anywhere in the state.

Frost dates from NOAA

Dates are the NOAA 1991-2020 normals for the last spring and first fall 32 F freeze at 50% probability. Tupelo Regional Airport in the north averages March 21 and November 10, Jackson International Airport March 14 and November 14, and Meridian Key Field March 16 and November 12. Gulfport-Biloxi Airport on the coast averages February 23 and December 3.

That is about 234 frost-free days at Tupelo, 245 at Jackson, 241 at Meridian and 283 at Gulfport (our arithmetic). The coast gains about seven weeks over the north, which fits MSU giving the coast monthly feedings and the north three.

Spring

MSU says to start a fertilizer program after correcting any soil test problems, and not to fertilize before the grass is actively growing. Its Table 9 puts the first bermudagrass and zoysiagrass feeding on April 1 on the coast, April 15 in zone 8a and May 1 to May 15 farther north. Tall fescue gets March 1 and April 1 feedings in zone 7a, and only March 1 in zone 7b.

Planting windows open the same way. Zoysiagrass can go in from March 1 on the coast, St. Augustinegrass from March 15 on the coast and April 15 in the center, and bermudagrass from April 15 on the coast and May 1 in the center. MSU says to mow new grass at 2 inches and return to normal height after about 6 weeks, and to skip chemical weed control on new lawns until at least 2 months after establishment.

Summer

MSU says most grasses need about 1 inch of water a week while actively growing: if more than half an inch of rain fell in the past week, skip watering; if none fell, add 1 inch, and try to water once a week. Its mowing table lists bermudagrass at about a half to one and a half inches, zoysiagrass at 1 to 1.5, St. Augustinegrass 2.5 to 3 and centipedegrass 1.5 to 2, with tall fescue at 3 to 4 inches in summer and bluegrass at 2 to 3. Never remove more than a third of the leaf at once.

Seeded bermudagrass needs fewer feedings than hybrid in the center of the state: May 1, June 1 and August 1 in zone 7b and April 15, May 15 and June 15 in zone 8a. Thatch under half an inch can help the lawn, and MSU says to remove it once it passes one inch, by vertical mowing and by fixing the compaction, drainage or low pH that caused it.

Fall

Cool-season seeding is a fall job in the north: MSU lists bluegrass, tall fescue and creeping red fescue for September 1 to November 1 in zone 7a, and tall fescue for September 15 to November 1 in zone 7b only. Kentucky bluegrass gets feedings on September 15, October 15, March 15 and April 15, and tall fescue on September 15 in zone 7b.

To keep a green lawn over a dormant warm-season one, MSU describes winter overseeding with perennial or annual ryegrass, planted October 15 to November 30 in the north, October 1 to November 15 in the center and September 15 to November 1 on the coast. MSU adds that ryegrass should disappear before it competes with the returning warm-season grass.

Fertilizer rules and soil tests

MSU says a soil test comes first, with a sample about every three years sent to the MSU Soil Testing Laboratory through the county extension office. It notes that many Mississippi soils have enough phosphorus and advises not adding it unless the test shows a need, while most Mississippi soils need potassium. I found no Mississippi rule restricting phosphorus in home lawn fertilizer in the sources I opened, and I could not find a state agency page that settles the question.

The lawn fertilizer calculator on this site does the division MSU shows: pounds of nitrogen wanted divided by the nitrogen percent on the bag. MSU gives the same example: 6 pounds of nitrogen a year from ammonium sulfate (21 percent nitrogen) is nearly 29 pounds of product, split into six applications.