South Carolina planting calendar
When to plant summer squash in South Carolina — sow, transplant & harvest dates
South Carolina is mostly USDA zone 8a (range 7a-9a). Dates below are derived from summer squash's frost tolerance and South Carolina's frost window — not generic national averages.
Summer squash planting timetable for South Carolina
| Stage | When in South Carolina | Anchor |
|---|---|---|
| Start seeds indoors | early March (March 4) | 3 weeks before the last frost (late March) |
| Transplant outside | early April (April 8) | 14 days after the last frost (late March) |
| First harvest (estimate) | early June (June 2) | ~55 days from transplant |
Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.
Why South Carolina's climate shifts the summer squash dates
South Carolina's last spring frost averages late March and first fall frost early November, which sets the whole planting clock. South Carolina has a long, hot, humid season with mild winters. The coast is nearly frost-free; the upstate sees a brief cold spell. Wait for warm soil — summer squash stall in cold ground even after the air warms, so don't rush them out.
Summer squash (zucchini, yellow crookneck, pattypan) wants the same warm soil as cucumbers — 18 °C minimum at sowing depth. A single plant can outproduce a small family once it gets going, so don't over-plant.
Frost-risk note
Don't plant before late March — even a light frost will kill seedlings overnight. In the Blue Ridge upstate near the mountains (zone 7a) the safe date runs a week or two later.
Regional variation within South Carolina
the Blue Ridge upstate near the mountains (zone 7a) runs roughly 1-2 weeks behind the state average; the Lowcountry coast around Charleston (zone 9a) can plant 1-2 weeks earlier.
- Columbia — USDA zone 8b
- Charleston — USDA zone 9a
- Greenville — USDA zone 8a
- Myrtle Beach — USDA zone 8b
What else to plant in South Carolina around then
Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.
Quick-grow guide
- Sun: Full sun — 6-8 hours direct.
- Soil temperature for germination: 21-29 °C (70-85 °F).
- Spacing: 24-36 inches (60-90 cm) between plants.
- Days to harvest: ~55 days from planting out.
Frequently asked questions
When is the best time to plant summer squash in South Carolina?
In South Carolina (mostly USDA zone 8a), sow summer squash indoors around early March, transplant outdoors early April (after the last frost, late March), and harvest from early June. Summer squash are frost-tender — a single light frost kills seedlings, so they only go outside once frost danger has fully passed and the soil is warm.
What USDA zone is South Carolina?
Most of South Carolina sits in USDA hardiness zone 8a, with the state spanning roughly 7a-9a from the Blue Ridge upstate near the mountains (zone 7a) to the Lowcountry coast around Charleston (zone 9a). The last spring frost averages late March and the first fall frost early November.
Can you grow summer squash in South Carolina?
Yes. South Carolina's dominant zone 8a supports summer squash — the key is timing. Summer squash are frost-tender — a single light frost kills seedlings, so they only go outside once frost danger has fully passed and the soil is warm.
Does the planting date change across South Carolina?
the Blue Ridge upstate near the mountains (zone 7a) runs roughly 1-2 weeks behind the state average; the Lowcountry coast around Charleston (zone 9a) can plant 1-2 weeks earlier.
What else can I plant in South Carolina around the same time?
Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.
Source and methodology
State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.
Keep going
- How to grow summer squash — full guide
- USDA zone 8 — frost dates and what else to plant
- Average frost dates by zone
- Frost-date calculator
- Month-by-month planting calendar
- When to plant summer squash in every US state
Same crop, nearby states (Southeast)
- When to plant summer squash in Alabama
- When to plant summer squash in Arkansas
- When to plant summer squash in Florida
- When to plant summer squash in Georgia
- When to plant summer squash in Kentucky
- When to plant summer squash in Louisiana
- When to plant summer squash in Mississippi
- When to plant summer squash in North Carolina