Seed germination temperature & time chart
How long seeds take to sprout, and the soil temperature they need — by seed type. Filter the chart, then open a seed for a germination planner (soil temperature → expected days and a sprout date) and a printable card. Data is curated from OSU Extension, Johnny’s Selected Seeds, and UC ANR.
Seed germination time & temperature chart
| Seed | Days to germinate | Optimal soil temp | Germination range | Depth | Season |
|---|---|---|---|---|---|
| Tomato | 5-14 days | 70-85 °F | 50-95 °F | 1/4 in | Warm-season |
| Cucumber | 3-10 days | 70-95 °F | 60-105 °F | 3/4 in | Warm-season |
| Carrot | 10-21 days | 55-75 °F | 40-95 °F | 1/4 in | Cool-season |
| Marigold | 5-10 days | 70-75 °F | 65-85 °F | 1/8 in | Warm-season |
| Zinnia | 4-10 days | 70-85 °F | 65-90 °F | 1/4 in | Warm-season |
How to use the chart
Germination is driven by soil temperature, not air temperature — use a soil thermometer for best results. Warm-season seeds (tomato, cucumber, marigold, zinnia) need warm soil to sprout quickly; cool-season seeds (carrot) tolerate cooler soil but are slower. Each seed page has a planner that turns your measured soil temperature into an expected day range and sprout date.