Here is a basic vegetable seed germination chart to use for planning and planting your garden.
Table 1.0: Optimal soil temperature range for seed germination of popular garden vegetables in °F (US customary units)
| Vegetable seed | Low end of optimum soil temperature range (°F) | High end of optimum soil temperature range (°F) |
|---|---|---|
| Pea | 40 | 75 |
| Lettuce | 40 | 80 |
| Spinach | 45 | 75 |
| Carrot | 45 | 85 |
| Cauliflower | 45 | 85 |
| Radish | 45 | 90 |
| Cabbage | 45 | 95 |
| Beet | 50 | 85 |
| Chard | 50 | 85 |
| Onion | 50 | 95 |
| Bean | 60 | 85 |
| Tomato | 60 | 85 |
| Corn | 60 | 95 |
| Cucumber | 60 | 95 |
| Pepper | 65 | 95 |
| Pumpkin | 70 | 90 |
| Squash | 70 | 95 |
| Melon | 70 | 95 |
Table 2.0: Optimal soil temperature range for seed germination of popular garden vegetables in °C (metric units)
| Vegetable seed | Low end of optimum soil temperature range (°C) | High end of optimum soil temperature range (°C) |
|---|---|---|
| Pea | 4 | 24 |
| Lettuce | 4 | 27 |
| Spinach | 7 | 24 |
| Carrot | 7 | 29 |
| Cauliflower | 7 | 29 |
| Radish | 7 | 32 |
| Cabbage | 7 | 35 |
| Beet | 10 | 29 |
| Chard | 10 | 29 |
| Onion | 10 | 35 |
| Bean | 16 | 29 |
| Tomato | 16 | 29 |
| Corn | 16 | 35 |
| Cucumber | 16 | 35 |
| Pepper | 18 | 35 |
| Pumpkin | 21 | 32 |
| Squash | 21 | 35 |
| Melon | 21 | 35 |
Reference: Knott’s Handbook for Vegetable Growers (Sixth Edition)