How long do tomato seeds take to germinate?
Tomato seeds sprout in 5-14 days at an optimal soil temperature of 70-85 °F. Use the planner to estimate days and a sprout date for your soil temperature.
Quick answer
Germination planner
Temperature range & printable card
Notes & troubleshooting
A warm-season crop usually started indoors 6-8 weeks before the last frost. Bottom heat to about 75-80 F speeds and evens germination.
If they will not sprout
- Too cold: below ~60 F soil, seeds are slow and prone to rot — use a heat mat.
- Leggy seedlings: provide strong light immediately after sprouting, not heat.
- Old seed: tomato seed stays viable ~4-6 years; expect slower, patchier germination as it ages.
Sources & how the planner works
The germination range (50-95 °F), optimal band (70-85 °F), 5-14 days to germinate, and 1/4 in sowing depth are curated from the sources below and last reviewed 2026-06-18.
The germination planner is DETERMINISTIC interpolation over the cited temperature ranges, not a prediction model. Below the minimum soil temperature, seeds are flagged as unlikely to germinate (and may rot); within the optimal band they sprout fastest (toward the low day count); between minimum and optimal they sprout slower (toward the high day count); above the maximum, germination drops or seeds go dormant. The 'sow date -> sprout window' is simply the sow date plus the expected day range for the chosen temperature band. It is general guidance, not a zone-based planting calendar.
General seed-starting guidance only. Soil temperature (not air temperature) drives germination; use a soil thermometer for best results. Verify timing for your specific variety and region; extension services publish local recommendations.