When to plant tomatoes
Tomatoes are frost-tender: a single night at 32°F kills the plant, and nights below 50°F stall growth and flowering. The reliable rule is to plant out one to three weeks after your average last frost, once nights stay above 50°F and soil at planting depth reaches about 60°F.
Start seeds six to eight weeks before your last frost so transplants are sturdy, 6–10 inches tall and just starting to bud when it is warm enough outside. Older, leggy seedlings sulk after transplanting.
- Start seeds indoors
- 6–8 weeks before last frost
- Transplant outside
- 1–3 weeks after last frost
- Frost
- Frost-tender: killed at 32°F
- Soil temp
- 60°F (16°C) or warmer
- Depth
- ¼ in (seed)
- Spacing
- 24 in apart, rows 36 in · 1 per square foot
- Harvest
- 60–85 days from transplant
Your dates for tomatoes
Tips for growing tomatoes
- Harden off seedlings over 7–10 days: a few hours of outdoor shade first, working up to full sun and nights outside.
- Plant deep. Tomato stems root along any buried length, so bury leggy transplants up to the first true leaves.
- In short-season areas pick early varieties (55–65 days) or cover plants with row cover on cool nights.
- Water deeply and evenly; irregular watering is a main trigger for blossom-end rot.
Choosing neighbours? See companion plants for tomatoes. Working out how many fit? Use the spacing calculator.
Tomatoes: common timing questions
Is it too late to plant tomatoes?
Count back from your first fall frost. If there are more days left than the variety’s days to maturity plus about two weeks, you can still plant transplants. Many areas can plant until early summer.
Can I plant tomatoes before the last frost?
Only with protection such as a cold frame, wall-of-water or heavy row cover, and even then growth is slow until nights warm above 50°F.
What soil temperature do tomatoes need?
About 60°F or warmer at planting depth. Cooler soil does not kill plants but they sit still until it warms.