St. Petersburg, Florida: planting zone & frost dates
St. Petersburg is in USDA plant hardiness zone 10b, where the average coldest winter night reaches 35 to 40°F (1.7 to 4.4°C). The typical last spring frost is around Jan 28 and the first fall frost around Jan 7.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Feb 5 | Dec 23 |
| Typical planning date (30% risk) | Jan 28 | Jan 7 |
| Median (50%) | Jan 17 | Jan 15 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station ST PETERSBURG, FL (USC00087886), 1.1 mi (1.8 km) from the city center and 30 ft lower than the city center (-9 m). Record used for the 1991–2020 normals: 22 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across St. Petersburg
St. Petersburg spans more than one half-zone. Share of the city's land area by zone (via its 14 ZIP codes): 10b (87%), 10a (13%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for St. Petersburg
Dates are counted from the 30%-risk frost dates above (last frost Jan 28, first frost Jan 7). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Dec 3 – Dec 17 | Feb 4 – Feb 18 | — | — |
| Pepper | Nov 19 – Dec 3 | Feb 11 – Feb 25 | — | — |
| Lettuce Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 17 – Dec 31 | Jan 14 – Feb 4 | Dec 31 – Feb 11 | Oct 29 – Nov 26 |
| Green Beans | — | — | Feb 4 – Mar 11 | Oct 15 – Oct 29 |
| Sweet Corn | — | — | Feb 4 – Mar 4 | — |
| Zucchini & Summer Squash | Dec 31 – Jan 7 | Feb 4 – Feb 18 | Feb 4 – Feb 25 | Oct 15 – Oct 29 |
| Cucumber | Dec 31 – Jan 7 | Feb 11 – Feb 18 | Feb 4 – Feb 25 | Oct 15 – Oct 29 |
| Carrot Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 7 – Feb 11 | Oct 15 – Oct 29 |
| Onion Mild winters: fall and winter plantings are usually more reliable than spring. | Nov 5 – Nov 19 | Dec 31 – Jan 14 | — | — |
| Potato Mild winters: fall and winter plantings are usually more reliable than spring. | — | Dec 31 – Jan 21 | — | — |
| Basil | Dec 17 – Dec 31 | Feb 11 – Feb 25 | Feb 11 – Mar 4 | — |
| Spinach Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 17 – Jan 14 | Nov 12 – Dec 10 |
| Kale Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 3 – Dec 17 | Dec 31 – Jan 21 | Dec 31 – Jan 21 | Oct 29 – Nov 26 |
| Broccoli Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 3 – Dec 17 | Jan 14 – Feb 4 | — | Oct 15 – Oct 29 |
| Peas Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 17 – Jan 7 | Oct 29 – Nov 12 |
| Eggplant | Nov 19 – Dec 3 | Feb 11 – Feb 25 | — | — |
| Cabbage Mild winters: fall and winter plantings are usually more reliable than spring. | Dec 3 – Dec 17 | Dec 31 – Jan 14 | — | Oct 15 – Oct 29 |
| Radish Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Dec 24 – Feb 11 | Nov 26 – Dec 24 |
| Strawberry | — | Dec 31 – Jan 21 | — | — |
| Beets Mild winters: fall and winter plantings are usually more reliable than spring. | — | — | Jan 7 – Feb 18 | Oct 29 – Nov 12 |
Nearby cities in Florida
- Largo — zone 10a, last frost Jan 26, first frost Jan 6
- Clearwater — zone 10a, last frost Jan 26, first frost Jan 6
- Tampa — zone 10a, last frost Jan 31, first frost Jan 3
- Lakeland — zone 10a, last frost Feb 3, first frost Jan 1
- North Port — zone 10a, last frost Feb 11, first frost Dec 28
- Cape Coral — zone 10b, last frost Jan 28, first frost Jan 7
More: all Florida cities · other zone 10b cities: San Diego, CA, San Francisco, CA, Long Beach, CA, Anaheim, CA, Irvine, CA, Santa Ana, CA, Chula Vista, CA, Cape Coral, FL
St. Petersburg gardening questions
When is the last frost in St. Petersburg, FL?
Plan around Jan 28. At NOAA's St Petersburg, FL station, 1.1 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Jan 17, and after Feb 5 the risk drops to about 1 in 10. The 90% and 10% dates are 36 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in St. Petersburg, FL?
Start seeds indoors Dec 3 – Dec 17 and set transplants outside Feb 4 – Feb 18, once nights stay above 50°F and the soil is near 60°F. With about 344 frost-free days, frost is not the main limit — fruit set drops when nights stay above about 75°F, so early plantings tend to do best. More: tomato planting dates by zone.
How long is the growing season in St. Petersburg?
About 365 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 357 days, and in 1 year in 10 it runs 365 days or more. In fall there is a 10% chance of frost by Dec 23 and a 30% chance by Jan 7. That ranks 2nd longest of 20 Florida cities on this site.
When should I plant a fall garden in St. Petersburg?
Count back from the first fall frost (Jan 7): transplant broccoli Oct 15 – Oct 29; sow kale Oct 29 – Nov 26; sow lettuce Oct 29 – Nov 26; sow radishes Nov 26 – Dec 24. How the math works: succession and fall planting.
Did St. Petersburg's hardiness zone change on the 2023 map?
Yes. Most of St. Petersburg was zone 10a on the 2012 map and is zone 10b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
Is all of St. Petersburg in zone 10b?
No. Zone 10b covers about 87% of the city's land; the rest is in 10a (13%), measured across the city's 14 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.