In general, it is better to sow your seeds a little late rather than too
early. If the soil temperature is not warm enough for the variety of
seed you are sowing, the seed will often rot in the ground before it has a
chance to germinate. This is especially true with seeds that have
not been treated with a chemical fungicide. ( We do not recommend using
treated seeds).
Remember - the temperatures listed below are for the
soil, not the air.
In the spring, the air temperatures may be warm for a
few days, but this will have little effect on the soil temperature.
Only when the days and nights both stay warm for an extended period of
time will the soil temperature start to rise.
| VARIETY |
OPTIMUM SOIL TEMPERATURE FOR
GERMINATION |
DAYS TO GERMINATE AT OPTIMUM SOIL
TEMPERATURE |
| Bean, lima |
85 degrees F |
7 to 10 days |
| Bean, snap |
75 to 80 degrees F |
7 days |
| Beet |
75 degrees F |
7 to 14 days |
| Broccoli |
65 to 75 degrees F |
5 to 10 days |
| Brussels sprout |
68 to 75 degrees F |
5 to 10 days |
| Cabbage |
68 to 75 degrees F |
5 to 10 days |
| Cantaloupe |
80 to 85 degrees F |
5 to 10 days |
| Carrot |
75 degrees F |
12 to 15 days |
| Cauliflower |
65 to 75 degrees F |
5 to 10 days |
| Celery |
70 to 75 degrees F |
10 to 14 days |
| Collard |
70 to 75 degrees F |
5 to 10 days |
| Corn |
75 to 85 degrees F |
7-10 days |
| Cucumber |
70 to 85 degrees F |
7 to 10 days |
| Eggplant |
75 to 85 degrees F |
10 to 12 days |
| Endive |
70 to 75 degrees F |
10 to 14 days |
| Kale |
70 to 75 degrees F |
5 to 10 days |
| Kohlrabi |
70 to 75 degrees F |
5 to 10 days |
| Lettuce |
65 to 70 degrees F |
7 to 10 days |
| Melon |
80 to 85 degrees F |
5 to 10 days |
| Mustard Greens |
70 degrees F |
5 to 10 days |
| Okra |
80 to 85 degrees F |
7 to 14 days |
| Onion, bulbing |
70 to 75 degrees F |
10 to 14 days |
| Onion, bunching |
60 to 70 degrees F |
10 to 14 days |
| Parsnip |
70 degrees F |
14 to 21 days |
| Pea |
65 to 70 degrees F |
7 to 14 days |
| Pepper |
78 to 85 degrees F |
10 to 14 days |
| Pumpkin |
70 to 75 degrees F |
7 to 10 days |
| Radish |
65 to 70 degrees F |
5 to 7 days |
| Rutabaga |
65 to 70 degrees F |
7 to 15 days |
| Spinach |
70 degrees F |
7 to 14 days |
| Spinach, New Zealand |
75 degrees F |
10 to 15 days |
| Squash, Summer |
75 to 85 degrees F |
7 to 14 days |
| Squash, Winter |
75 to 80 degrees F |
7 to 14 days |
| Swiss Chard |
70 to 75 degrees F |
7 to 14 days |
| Tomato |
75 to 80 degrees F |
7 to 14 days |
| Turnip |
65 to 70 degrees F |
7 to 14 days |
| Watermelon |
75 to 85 degrees F |
7 to 14 days |
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