Soil temperatures vital to success of crops
Few gardeners check the soil temperature before planting, yet it’s probably the most important factor affecting seed germination and plant growth.
Soil temperatures at which vegetable seeds will grow include the minimum, optimum and “realistic” figures. The realistic soil temperature is somewhere between optimum and minimum; it’s the temperature at which you should plant to
have the best chance of success.
For instance, the optimum soil temperature for seed germination of vegetable crops such as cucumber, cantaloupe, okra, pumpkin, squash and watermelon is 95
degrees. But if you wait until the soil gets that warm to plant, the summer heat will take its toll on your plants’ vigor and yield.
The minimum for these crops is 60 degrees. But when the soil is that cool, the seeds won’t grow vigorously. Realistic soil temperatures for the best plant production are 64 degrees for cucumber, 68 for cantaloupe, 70 for squash, 72 for watermelon, 73 for okra and 75 for pumpkin.
The realistic soil temperature for beets is 45, turnips 50, tomatoes and corn 55 and beans 72. The seeds of really cold-tolerant vegetables such as carrots, parsley, lettuce, and spinach can germinate in soils as cold as 35 degrees. The realistic temperature for all of these crops is 45 degrees.
If you have any questions regarding your plants, in- or out-of-doors; please contact the extension office at 770-749-2142 or email uge2233@ uga.edu.
For more information and details on upcoming events, check out the Polk County Extension office on Facebook by searching “UGA Extension Polk County.”