Tomato · last checked 2026-09-27
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. The Extension pages below agree on the basic rule: wait until frost danger has passed.
Each line names the Extension service it comes from and links to their page. Oregon's dates are for Oregon'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
- Oregon State University Extension says to set out sturdy transplants after the last frost, starting them indoors about eight weeks before the planting date for your region. Vegetable Gardening in Oregon (EC 871) · checked 2026-09-27
State planting dates
| Who says | Region | Planting window | Source |
|---|---|---|---|
| Oregon State University Extension says | Oregon, region 1: coast, Astoria to Brookings | May to June | Vegetable Gardening in Oregon (EC 871) · checked 2026-09-27 |
| Oregon State University Extension says | Oregon, region 2: western valleys, Portland to Roseburg | May | Vegetable Gardening in Oregon (EC 871) · checked 2026-09-27 |
| Oregon State University Extension says | Oregon, region 3: high elevations of central and eastern Oregon | May | Vegetable Gardening in Oregon (EC 871) · checked 2026-09-27 |
| Oregon State University Extension says | Oregon, region 4: Columbia and Snake valleys (Hermiston, Pendleton, Ontario) | May | Vegetable Gardening in Oregon (EC 871) · checked 2026-09-27 |
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
- Oregon State University Extension says to allow 24 inches between plants and 36 inches between rows, or less between rows when plants are supported. Vegetable Gardening in Oregon (EC 871) · checked 2026-09-27
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
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.