Charleston, SC planting zone & frost dates
Charleston is in USDA hardiness zone 9a. The last spring frost usually comes around February 4 and the first fall frost around December 30, for a growing season of about 321 days.
Planting calendar for Charleston
Dates are counted from the average last spring frost (February 4) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Dec 10 – Dec 24 Transplant outdoors: Feb 11 – Feb 18 |
| Peppers | Start seeds indoors: Nov 26 – Dec 10 Transplant outdoors: Feb 18 – Feb 25 |
| Eggplant | Start seeds indoors: Nov 26 – Dec 10 Transplant outdoors: Feb 18 – Feb 25 |
| Broccoli | Start seeds indoors: Nov 26 – Dec 10 Transplant outdoors: Jan 7 – Jan 21 |
| Cabbage | Start seeds indoors: Nov 26 – Dec 10 Transplant outdoors: Jan 7 – Jan 21 |
| Onions (sets) | Plant outdoors: Jan 7 – Jan 21 |
| Peas | Sow outdoors: Dec 24 – Jan 7 |
| Spinach | Sow outdoors: Dec 24 – Jan 7 |
| Lettuce | Sow outdoors: Jan 7 – Jan 21 |
| Carrots | Sow outdoors: Jan 7 – Jan 21 |
| Potatoes | Plant outdoors: Jan 7 – Jan 21 |
| Beans | Sow outdoors: Feb 11 – Feb 18 |
| Sweet corn | Sow outdoors: Feb 11 – Feb 18 |
| Cucumbers | Sow outdoors: Feb 11 – Feb 18 |
| Squash & zucchini | Sow outdoors: Feb 11 – Feb 18 |
| Basil | Start seeds indoors: Dec 24 – Jan 7 Transplant outdoors: Feb 11 – Feb 18 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Nov 4 (8 weeks before the average first fall frost on Dec 30).
Useful for zone 9a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Jan 5 | Feb 4 | Mar 4 |
| First 32°F frost in fall is before | Jan 25 | Dec 30 | Dec 2 |
How to read it: in spring there is a 10% chance of a frost after March 4, so that is a safe date for tender plants. In fall there is a 10% chance of frost before December 2. A hard freeze (28°F) usually ends around January 24.
Hardiness zone by ZIP code in Charleston
- 29401 zone 9a
- 29402 zone 9a
- 29403 zone 9a
- 29406 zone 9a
- 29407 zone 9a
- 29412 zone 9a
- 29413 zone 9a
- 29414 zone 9a
- 29416 zone 9a
- 29417 zone 9a
- 29422 zone 9a
- 29423 zone 9a
- 29492 zone 9a
Nearby cities
- Mount Pleasant zone 9a, last frost Mar 13
- North Charleston zone 9a, last frost Mar 7
- Hanahan zone 9a, last frost Mar 7
- Goose Creek zone 9a, last frost Mar 7
- Ladson zone 8b, last frost Mar 7
- Summerville zone 8b, last frost Mar 22
- Beaufort zone 9a, last frost Mar 3
- Port Royal zone 9a, last frost Mar 3
Questions
What growing zone is Charleston, SC?
Charleston is in USDA Plant Hardiness Zone 9a (average extreme winter low 20°F to 25°F), according to the USDA 2023 map.
When is the last frost in Charleston?
The average last spring frost (32°F) in Charleston is February 4. There is still a 10% chance of frost until March 4.
When can I plant tomatoes in Charleston?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Feb 11 – Feb 18. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Charleston City, SC (USW00013782), 0.4 km (0.2 mi) from the city center, elevation 3 m, based on 30 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.