This evening my son and I put in soil heating cables in to the pumpkin patch planting areas about 6-8 inches down in the soil. These cables will be left in the soil the entire season and will help make sure the root zone is at least 70 degrees. When the soil is warmer, to a certain limit, more biology will be active in the soil and will help feed the plants. In the spring, in particular, the soils can be cold, and if you transplant into cold soil it can make for very unhappy plants.
Right now I have the soil heating cables in and then clear plastic on top of the soil which will further help to heat the soil. Prior to installing the heating cables I tested the temperature about 7 inches down. It was 63 degrees. Not bad, but in the next week I expect it to get up to at least 70 degrees which will keep the plants happy.
In the greenhouse I'm not adding the heating cables. It will use the geothermal system, which I still need to get the fan hooked up to. I checked that soil and it is 69.8 degrees right now in the planting areas. I have clear plastic on the planting area it and when I get the greenhouse closed up I should easily get the soil to about 75 degrees in the next week.