See links below from Harvest to Table.com with plant-specific advice including soil temps.
Min/Opt/Max temps from IFAS
MINIMUM Soil Temperature for Germination
- 32° – Endive, Lettuce, Onion, Parsnip, and Spinach
- 40° – Beet, Broccoli, Cabbage, Carrot, Cauliflower, Parsley, Pea, Radish, Swiss Chard, and Celery
- 50° – Asparagus, Sweet Corn, Tomato, and Turnip
- 60° – Lima bean, Snap Bean, Cucumber, Okra, and Pepper
- 65° – Eggplant, Muskmelon, Pumpkin, Squash, and Watermelon
OPTIMUM Soil Temperature for Germination
- 70° – Celery, Parsnip, and Spinach
- 75° – Asparagus, Endive, Lettuce, and Pea
- 80° – Lima Bean, Carrot, Cauliflower, Onion, Radish, Tomato, Turnip
- 85° – Snap Bean, Beet, Broccoli, Cabbage, Eggplant, Parsley, Pepper, Sweet Corn, and Swiss Chard
- 95° – Cucumber, Muskmelon, Okra, Pumpkin, Squash, and Watermelon.
MAXIMUM Soil Temperature for Germination
- 75° – Celery, Endive, Lettuce, and Spinach
- 85° – Lima Beans, Parsnip, and Pea
- 95° – Asparagus, Snap Bean, Beet, Broccoli, Cabbage, Carrot, Cauliflower, Eggplant, Onion, Parsley, Pepper, Radish, Swiss Chard, and Tomato
- 106° – Cucumber, Muskmelon, Okra, Pumpkin, Squash, Sweet Corn, Turnip, and Watermelon
From Harvest to Table.com
- VEGETABLE SEED GERMINATION SPECIAL REQUIREMENTS
- SEED STARTING SPECIFIC CROPS
- VEGETABLE SEED GERMINATION TEMPERATURES – Table extracted below.
| Crop | Germination Minimum Soil Temperature (°F) | Germination Optimum Soil Temperature Range (°F) | Germination Maximum Soil Temperature (°F) | Days to Germination at Optimal Temps |
| Asparagus | 50 | 60-85 | 95 | 14-18 |
| Bean, lima | 60 | 75-85 | 85 | 4-10 |
| Bean, snap | 60 | 75-85 | 95 | 4-10 |
| Beet | 40 | 60-85 | 95 | 4-10 |
| Broccoli | 40 | 60-85 | 95 | 7-10 |
| Brussels sprouts | 40 | 60-85 | 95 | 3-10 |
| Cabbage | 40 | 60-85 | 95 | 5-10 |
| Carrot | 40 | 65-85 | 95 | 6 |
| Cauliflower | 40 | 65-85 | 95 | 4-10 |
| Celery | 40 | 60-70 | 95 | 10 |
| Chinese cabbage | 40 | 60-85 | 95 | 4-10 |
| Collards | 40 | 60-85 | 95 | 5-10 |
| Corn | 50 | 65-95 | 105 | 4-10 |
| Cucumber | 60 | 65-95 | 105 | 5-7 |
| Eggplant | 60 | 75-85 | 95 | 10-15 |
| Endive/Escarole | 35 | 60-75 | 85 | 10-14 |
| Garlic | 35 | 65-85 | 95 | 7-14 |
| Kale | 40 | 60-85 | 95 | 5-7 |
| Kohlrabi | 40 | 60-95 | 105 | 5-10 |
| Leeks | 35 | 65-85 | 95 | 8-16 |
| Lettuce | 35 | 60-75 | 85 | 2-10 |
| Muskmelon | 60 | 75-95 | 105 | 4-10 |
| Mustard | 35 | 60-75 | 85 | 4-6 |
| Okra | 60 | 85-95 | 105 | 7-12 |
| Onion | 35 | 65-85 | 95 | 4-12 |
| Parsley | 40 | 65-85 | 95 | 5-6 weeks |
| Parsnip | 35 | 65-75 | 85 | 5-28 |
| Pea | 40 | 65-75 | 85 | 5-7 |
| Pepper | 60 | 65-75 | 95 | 7-10 |
| Pumpkin | 60 | 85-95 | 105 | 4-10 |
| Radicchio | 35 | 60-75 | 85 | 5-7 |
| Radish | 40 | 65-85 | 95 | 4-10 |
| Spinach | 35 | 65-75 | 75 | 6-14 |
| Squash | 60 | 85-95 | 105 | 7-10 |
| Swiss chard | 40 | 65-85 | 95 | 7 |
| Tomato | 50 | 65-85 | 95 | 5-7 |
| Turnip | 40 | 60-95 | 105 | 3-10 |
| Watermelon | 60 | 70-95 | 105 | 4-10 |
