Soil Temperature Conditions for Vegetable Seed Germination

Daily fluctuation to 60 °F or lower at night is essential.

Vegetable Minimum (°F) Optimum Range (°F) Optimum (°F) Maximum (°F)
Asparagus 50 60-85 75 95
Bean 60 60-85 80 95
Bean, Lima 60 65-85 85 85
Beet 40 50-85 85 95
Cabbage 40 45-95 85 100
Carrot 40 45-85 80 95
Cauliflower 40 45-85 80 100
Celery 40 60-70 70² 85²
Chard, Swiss 40 50-85 85 95
Corn 50 60-95 95 105
Cucumber 60 60-95 95 105
Eggplant 60 75-90 85 95
Lettuce 35 40-80 75 85
Muskmelon 60 75-95 95 100
Okra 60 70-95 95 105
Onion 35 50-95 75 95
Parsley 40 50-85 75 90
Parsnip 35 50-70 65 85
Pea 40 40-75 75 85
Pepper 60 65-95 85 95
Pumpkin 60 70-90 90 100
Radish 40 45-90 85 95
Spinach 35 45-75 70 85
Squash 60 70-95 95 100
Tomato 50 60-85 85 95
Turnip 40 60-105 85 105
Watermelon 60 70-95 95 105

Compiled by J. F. Harrington, Department of Vegetable Crops, University of California, Davis.