Knowing the correct soil temperature is critical to planting many vegetables and food crops. It is not the air temperature that determines when it is okay to plant seeds and seedlings, it is the soil temperature. If you plant seeds in soil that is still too cold, the seeds will just sit there and often will rot. Seedlings planted in cold soil will sit there until the soil is warm enough and will probably be stunted for the rest of the season.

While you can plant seeds for the early vegetables like peas, radish, spinach, and Chinese cabbage when the soil temperature reaches 40 degrees, you will get much better results if you can be patient and wait until the temperature is between 45 and 50 degrees. For seedlings like cabbage, broccoli and cauliflower, you need to wait until the soil temperature is at least 50 degrees - and 55 degrees is better.

Warm weather vegetables such as tomatoes, peppers and cucumbers along with impatiens, ageratum and begonias should not be planted in the soil until that temperature is at least 65 degrees. It might be 80 degrees in the air but that soil temperature might still be hanging out at around 60 degrees. Patience is the password here.

Unit comes with temperature guidelines for germination on 20 different vegetables.

Temperature Range:

• -20° - +180° F;
• -6⁰° - +82° C