Sow warm-season grass seed in Florida once the soil, two inches down, reads 65°F and rising. In north Florida that means spring, after the last freeze has passed. Central and south Florida have no reliable frost to wait out, so their calendar runs differently, and one statewide date would be wrong for most of the peninsula. Fall sowing works in the north too, but it closes early. The seed needs about 45 days of growing weather before the first freeze.
The best time to sow grass seed in Florida
Warm-season seed won’t germinate on a date. It germinates on heat. Soil at 65 to 70°F and rising is the trigger, and the reading that counts is taken two inches down, mid-morning, with a probe thermometer. Air temperature on the porch tells you little. A warm March afternoon can sit on top of soil that is still too cold, and seed sown into it just sits there.
The grasses that qualify as seed-able or plantable in Florida are all warm-season species: bahiagrass, bermudagrass, carpetgrass, centipedegrass, seashore paspalum, St. Augustinegrass and zoysiagrass. Cool-season grasses such as tall fescue or Kentucky bluegrass do well in places like Ohio (see When to Plant Grass Seed in Ohio), but they stall and thin out in a long, hot, humid Florida summer. They may look fine for a few months and then fail, so skip them for a permanent lawn.
North Florida: wait out the last freeze
The best long-term numbers come from NOAA NCEI 1991-2020 Climate Normals for Jacksonville. At that station, the 32°F freeze probability sits in the 30 to 70 percent band from February 16 to March 7. Your spring sowing starts after that window closes and the soil thermometer agrees. Jacksonville’s station is an inland airport, though, so a coastal yard may be milder. Of thirty recent falls, three saw no freeze at all. Treat the window as a guide, not a guarantee.
Central and south Florida: the calendar flips
Never lay the Jacksonville window over Orlando or Miami. Central and south Florida are effectively frost-free, so there is no last-frost date to wait for. The growing calendar inverts. The main season runs through winter, when soil is warm enough and the weather is mild, and summer becomes the hard part, with heat stress and heavy downpours that wash seed around or rot young seedlings. Use the soil thermometer rather than a frost date, and aim for the stretch when seedlings won’t have to face midsummer immediately.
The last date that still works
Seed sown too late germinates and then dies over winter. The rule is about 45 days of growing weather before the first fall freeze, and you work backward from your own freeze date. That is the whole method.
For Jacksonville, NOAA’s first-freeze band runs November 26 to December 13. Count 45 days back from those and you land on roughly October 12 and October 29. The earlier date is the cautious one, and it’s the one to pick if you want margin. Today is October 1, so a north Florida yard has about two weeks of comfortable room by this arithmetic, and not much more.
Those 45 days are calendar days, though, and late-fall growing weather is slower than early-fall weather. Cooling nights shave real growth off every day. That’s another reason to treat October 12 as the safe end and October 29 as a gamble. And since three of thirty falls at that station had no freeze at all, a gamble sometimes pays off. You can’t count on it.
A hurricane season that runs through November 30 adds another wrinkle in late fall. A tropical rain event on freshly seeded sandy ground can move seed into low spots or leave it exposed, so check the forecast before you spread.
For central and south Florida, there is no first-freeze date to count back from, so this arithmetic doesn’t apply the same way. A firm last-sowing date for those regions isn’t published here, and I won’t guess one. Ask your county office of UF/IFAS Extension about local timing and watering rules, or compare how the neighboring Gulf states set their dates in When to Plant Grass Seed in Alabama and When to Plant Grass Seed in Louisiana.
Seed rate and soil preparation
What Florida ground tends to do
Florida’s official state soil is the Myakka series, named in 1989. USDA NRCS records its surface layer as a Spodosol: sandy, acid and strongly leached, typically under conifers. Representative surface values are a pH of about 5.1, which is strongly acid, 97 percent sand, 2 percent clay, 1 percent silt, and about 2.0 percent organic matter. It is also poorly drained.
That is the soil that represents the state, not necessarily the soil in your yard. Florida has hundreds of soil series, and ground scraped or filled by a builder can look nothing like this. Still, the tendency is useful. Sand holds little water and few nutrients, so seedlings dry out quickly and fertilizer leaches away. Where the water table is high, though, the same ground can sit wet after heavy rain. Get a soil test before you buy lime or fertilizer, because your own pH is the only number that matters. UF/IFAS Extension can point you to testing options through your county office.
How much seed
Rates below are pounds per 1,000 square feet for a new lawn. Overseeding an existing lawn uses half. More seed is not insurance, because crowded seedlings compete and thin each other out.
| Grass | New lawn, per 1,000 sq ft |
|---|---|
| Bahiagrass | 5 to 10 lb |
| Bermudagrass | 1 to 4 lb |
| Carpetgrass | 1 lb |
| Centipedegrass | 0.25 to 1 lb |
| Zoysiagrass | 1 to 2 lb |
| Seashore paspalum | Sod, sprigs or plugs only, not seed |
| St. Augustinegrass | Sod, sprigs or plugs only, not seed |
Read the last two rows twice. St. Augustinegrass is everywhere in Florida yards, yet it isn’t a seed-sown grass, so a bag claiming otherwise deserves suspicion.
Depth matters as much as rate. Cover seed no more than 0.25 inch and press it into the soil for good contact. Grass seed sown deeper often never emerges, which is the single most common reason a new lawn comes up patchy. Rake lightly, broadcast, then roll or tamp. In loose sand that firming step does a lot of work.
Watering a new lawn until it holds
Sandy ground gives you almost no safety margin. Seed sits in the top fraction of an inch, and that layer can go from damp to dry in an afternoon. The goal is a surface that never fully dries out until the seedlings are up and rooting. In practice that means short, frequent watering rather than one long soak, which would push seed into low spots and drain straight through anyway.
Once seedlings are up, start stretching the gap between waterings and lengthen each session, so roots follow moisture downward. Keep that up for several weeks, until the lawn has been mowed a few times and no longer wilts between waterings. Pulling back too early is the usual slip. The grass looks established, and then a dry week in sandy soil shows it wasn’t.
Check local rules before you set a schedule. Florida’s water management districts and many counties limit irrigation days, and they generally make some allowance for newly planted lawns, but the details differ by place. Your county extension office can tell you what applies. Rain helps, but a summer thunderstorm can dump a lot of water on sand in minutes, so check bare spots afterward and re-seed any washouts quickly.
For the full sequence from bare ground to first mowing, see Starting a New Lawn From Seed.
Common questions
Can I grow St. Augustinegrass from seed in Florida?
No. St. Augustinegrass and seashore paspalum are established from sod, sprigs or plugs only. If you want a seeded lawn, choose bahiagrass, bermudagrass, carpetgrass, centipedegrass or zoysiagrass.
Is early October too late to seed in north Florida?
Not yet, but the margin is thin. Counting 45 days back from NOAA’s Jacksonville first-freeze band, November 26 to December 13, gives about October 12 to October 29. Pick the earlier date if you want a cushion.
Do the Jacksonville dates apply to Orlando or Miami?
No. Central and south Florida are effectively frost-free, so there’s no freeze date to count from. Go by soil temperature, and expect the hard season to be summer, not winter.
Will extra seed give me a thicker lawn?
It usually backfires. Seedlings compete and thin out, so stick to the rate for your grass. Overseeding an existing lawn takes half the new-lawn rate, and cover the seed no deeper than 0.25 inch.