When can I plant tomatoes outdoors?
Why planting too early stunts tomatoes for the rest of the season, and how to know when it's actually safe.
Sera Mendel
February 3, 2026
Two conditions, both required
Last frost has passed for your zone. Nighttime temps consistently above 50°F (10°C) for at least a week.
Tomatoes can survive a 45°F night, but they don't grow. Plants set out too early sit there for weeks doing nothing — and a hardier neighbor planted 2 weeks later catches up.
Look up your zone, then add a buffer
USDA zones give average last-frost dates. Add 1–2 weeks to be safe — averages mean half the years are later.
Zone 5 (most of the Midwest, parts of Northeast): mid-May. Zone 7 (mid-Atlantic, Pacific Northwest): late April. Zone 9 (deep South, parts of California): early March.
Hardening off — the missing step
Plants started indoors need a week of gradual outdoor exposure before going in the ground. Day 1: 1 hour outside in shade. Build up to a full day in sun by day 7.
Skip this and you get sunburned, wind-shocked plants that take weeks to recover.
People also ask
What if a late frost is forecast?+
Cover plants with a sheet, towel, or frost cloth at sunset. Remove in the morning when temp is above 40°F.
Should I plant in a row or a cluster?+
Spaced rows — at least 24 inches apart. Crowding reduces airflow and invites disease.
Can I plant in containers earlier?+
Yes, with the same nighttime-temperature rule, since containers can be moved inside if it gets cold.