When to Plant Tomatoes Outside 2026 🍅
The most important rule in tomato growing: never transplant outdoors before your last frost date. Here are exact transplant dates for every USDA zone.
Published April 1, 2026
The Golden Rule of Tomato Transplanting
Tomatoes are killed by frost and stunted by cold soil. The two conditions that must be met before transplanting outdoors are: (1) all frost risk has passed and (2) nighttime temperatures are consistently above 50°F. Cold soil — even without frost — slows tomato growth dramatically and invites disease.
Min Soil Temp
60°F
for transplanting
Min Night Temp
50°F
consistently
Indoor Lead Time
7 weeks
before last frost
Tomato Outdoor Planting Dates by Zone
| Zone | Last Frost | Start Indoors | Transplant Outside |
|---|---|---|---|
| Zone 3a–3b | May 10–15 | Late Mar – Early Apr | Late May – Early Jun |
| Zone 4a–4b | Apr 24 – May 1 | Mid–Late Mar | Mid–Late May |
| Zone 5a–5b | Apr 7–15 | Late Feb – Early Mar | Late Apr – Mid May |
| Zone 6a–6b | Mar 22–30 | Early–Mid Feb | Early–Late Apr |
| Zone 7a–7b | Mar 5–15 | Mid–Late Jan | Mid–Late Mar |
| Zone 8a–8b | Feb 10–20 | Dec–Early Jan | Early–Late Mar |
| Zone 9a–9b | Jan 20–30 | Nov–Dec | Feb – Early Mar |
Before You Transplant — Checklist
✓Last frost date has passed for your zone
✓Night temperatures are consistently above 50°F
✓Seedlings have been hardened off for 7–10 days
✓Soil is workable and not waterlogged
✗Do NOT transplant if frost is forecast in the next 7 days
✗Do NOT plant in cold, wet soil — wait for conditions to improve
Calculate Your Tomato Dates
FAQs
What temperature is too cold to plant tomatoes outside?▼
Tomatoes should not be transplanted when nighttime temperatures are below 50°F. Temperatures below 50°F slow growth significantly and increase the risk of blossom drop and disease. Below 40°F, tomatoes stop growing entirely.
Can I plant tomatoes outside before the last frost if I cover them?▼
With protection like a frost cloth or Wall-O-Water, you can transplant 2–3 weeks before your last frost date. However, cold soil (below 60°F) will still stunt growth even if plants survive frost nights.
What happens if I plant tomatoes too early?▼
Plants transplanted into cold conditions suffer "transplant check" — they essentially stop growing for several weeks. A plant transplanted 2 weeks early may be smaller after a month than one planted at the correct time.