When temperatures drop suddenly after several days of unusually warm spring weather, what impact will that have?
Fluctuations will stress the plant a little, but usually will cause no long-term activity. They will slow down activity and growth which will resume with improved weather. 3. How does the ground temperature affect plants, and how do you know when the ground is warm enough to start young vegetables and flowers? Air temperature and soil temperature are totally different. It takes longer for the soil to warm up than the air, so the ground doesn’t necessarily warm up enough, even though there may be several warm days in a row. Most seeds need a soil temperature of between 60-75 degrees for optimum germination. If they are planted too early in cold soil and lots of moisture, you will get seed rot. Ground temperature does influence the time of spring growth for both perennials and biennials already in the garden. Jett recommends waiting to plant new perennials and biennials until after the danger of frost has past. Many of these plants are shipped in from southern nurseries with earlier seas
