Updated January 2015. The increased cost of health insurance is a central fact in any discussion of health policy and health delivery. As annual premiums edged beyond $16,800 for an average family, costs are blamed for rising uninsured and under-insurance..
Figure 1. Corn growth and temperature levels. Corn will germinate and grow slowly at about 50 F (10 C), but the average first spring planting dates across the U.S. usually begin when the average air temperatures reach 55 F (13 C) and soil temperature at seed depth is favorable for seedling growth.
Sweet corn, lima beans and some greens need 65 degrees F. (18 C.) Warmer temperatures into the 70s (20s C.) are required for watermelon, peppers, squash, and at the higher end, okra, cantaloupe and sweet potatoes. If you are in doubt, check your seed packet for ideal soil temperatures for planting. Most will list the month for your USDA zone. Realistic Soil Temperatures. Somewhere between the minimum soil temperature for plant growth and the optimum temperature is the realistic soil temperature. For instance, plants with higher temperature needs, such as okra, have an optimum temperature of 90 F. (32 C.).