Tomato · last checked 2026-09-28
When to plant tomatoes: frost, soil warmth and state dates
Tomatoes are set out as young plants, not sown in the garden, and they stall in cold nights. Illinois Extension's basic rule: plant once the soil is warm, soon after your area's frost-free date.
Each line names the Extension service it comes from and links to their page. South Carolina's dates are for South Carolina's own growing regions.
When to plant
- Illinois Extension says the safest time to transplant is soon after your area's frost-free date, once the soil is warm; plants set out too early can take up to two weeks to recover from cold nights. Tomato (Home Vegetable Gardening) · checked 2026-09-27
- Clemson Cooperative Extension says to start seed indoors six to eight weeks ahead of your last frost date, then harden plants off for about a week before moving them out. Tomato (HGIC fact sheet) · checked 2026-09-28
Sun and soil
- University of Wisconsin–Madison Extension says set tomato plants where they get full sun. Homegrown Tomatoes for Wisconsin (Wisconsin Horticulture) · checked 2026-09-28
Watering
- University of Wisconsin–Madison Extension says water at planting and in dry spells, soaking the soil 8 to 10 inches deep when it needs it. Frequent shallow watering keeps roots from developing well. Homegrown Tomatoes for Wisconsin (Wisconsin Horticulture) · checked 2026-09-28
- Illinois Extension says water deeply and regularly through long dry spells. Mulch and steady watering help prevent blossom-end rot. Tomato (Home Vegetable Gardening) · checked 2026-09-27
State planting dates
| Who says | Region | Planting window | Source |
|---|---|---|---|
| Clemson Cooperative Extension says | South Carolina, Coastal Plain counties | Spring: March 1 to April 30. Fall: July 1 to July 15. | Tomato (HGIC fact sheet) · checked 2026-09-28 |
| Clemson Cooperative Extension says | South Carolina, Piedmont counties | Spring: May 1 to June 30. Fall planting is not recommended. | Tomato (HGIC fact sheet) · checked 2026-09-28 |
Spacing
- Illinois Extension says dwarf plants need about 12 inches in the row, staked plants 15 to 24 inches, and trellised plants 24 to 36 inches; very vigorous indeterminate types may need 4 feet. Tomato (Home Vegetable Gardening) · checked 2026-09-27
- Clemson Cooperative Extension says sturdy transplants about 6 to 10 inches tall go 24 inches apart, in rows 3 feet apart. Tomato (HGIC fact sheet) · checked 2026-09-28
Harvest
- Illinois Extension says to pick fruit firm and fully colored; quality is highest when it ripens on healthy vines while daily temperatures average around 75 °F. Tomato (Home Vegetable Gardening) · checked 2026-09-27
- Illinois Extension says late plantings for a fall crop should be timed so fruit matures before a killing freeze, allowing up to 100 days from transplanting for most varieties. Tomato (Home Vegetable Gardening) · checked 2026-09-27
Further reading
- Vegetable Gardening in Oregon (EC 871) (Oregon State University Extension). Link only: we no longer quote this page.
Unless a line says otherwise, weeks are counted from the average last spring frost where you live. Find that date through your state’s Extension service. See how these pages are put together.
Other crops: Blueberry, Broccoli, Garlic, Okra, Potato, Pumpkin, Strawberry, Sweet potato.