When to plant zucchini / summer squash in South Carolina
South Carolina’s average last spring frost is March 25, and the first fall frost typically arrives around November 5 — about 225 frost-free days (USDA zones 7a, 7b, 8a, 8b, 9a). Zucchini / Summer Squash needs 45–60 days to mature, which fits comfortably within South Carolina's growing season.
When to plant zucchini / summer squash in South Carolina: the short answer
For a spring planting, plant out Mar 25 – Apr 11, with seeds started indoors Feb 25 – Mar 11. Wait until the soil is at least 60°F and frost is over.
Succession sow again in South Carolina: Apr 29 · May 27 · Jun 24 · Jul 22 · Aug 19
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow zucchini / summer squash in South Carolina, step by step
- Start seeds indoors (Feb 25 – Mar 11). Sow seeds 1 inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 85°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 14 inches deep, with a pH between 5.5 and 7.5. Dig in compost before planting.
- Plant out (Mar 25 – Apr 11). Space plants about 30 inches apart in rows 42 inches apart. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: squash vine borer, squash bug, striped cucumber beetle, aphids. Diseases and disorders: powdery mildew, bacterial wilt, blossom-end rot (calcium disorder).
- Harvest (from about May 16 – May 31). Zucchini / Summer Squash takes 45-60 days to reach harvest. One or two plants feed a household. A second sowing in early-mid summer dodges the first vine borer generation.
Figures come from our crop data; dates use South Carolina’s average frost dates. More in the full zucchini / summer squash growing guide.
Zucchini planting dates by USDA zone in South Carolina
South Carolina spans USDA zones 7a, 7b, 8a, 8b, 9a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the zucchini / summer squash dates shift with them.
When to plant zucchini / summer squash in nearby states
| State | Last frost | Plant out |
|---|---|---|
| South Carolina (this page) | March 25 | Mar 25 – Apr 11 |
| North Carolina | April 5 | Apr 5 – Apr 22 |
| Georgia | March 25 | Mar 25 – Apr 11 |
| Tennessee | April 10 | Apr 10 – Apr 27 |
| Kentucky | April 18 | Apr 18 – May 5 |
Questions gardeners in South Carolina ask
When is the best time to plant zucchini / summer squash in South Carolina?
Plant zucchini / summer squash transplants outdoors in South Carolina between March 25 and April 11. That timing is set by South Carolina's average last spring frost of March 25.
When should I start zucchini / summer squash seeds indoors in South Carolina?
Start seeds indoors between February 25 and March 11, about 3 weeks before the last frost, so the seedlings are ready to plant out from March 25.
Can I plant zucchini / summer squash in the fall in South Carolina?
Yes. For a fall crop, sow between August 3 and August 20, so the crop matures in cool weather before South Carolina's first frost around November 5.
When will zucchini / summer squash planted in South Carolina be ready to harvest?
Planted on time, zucchini / summer squash is usually ready from about May 16 to May 31, 45-60 days after planting.
When is the last frost in South Carolina?
On average around March 25, with the first fall frost around November 5 - about 225 frost-free days. Your town may differ by two weeks or more.