Keeping Cozy
Farming with Sue & Gary has not only given us access to land but also to new access to knowledge. Part of this includes using a small 12' by 80' hoop for season extension, as Richmond (zone 5b) generally only has 150 days in its growing season. A hoop house is a small structure built with metal hoops (8' to 20' tall) covered in UV resistant plastic, [compared to a greenhouse, which has more permanent walls, and implements to control heat, humidity and air flow]. Ours required some minimal repairs in autumn, and we are currently dealing with weed and rodent control, as it has been somewhat left to the conditions of Nature for a few years. In the spring, temperatures inside the hoop range from normal spring lows (18-35 degrees F) to protected highs (100-120 degrees F), peaking in the early afternoon on sunny days. The daytime temperatures are ideal conditions to encourage our seedlings into thinking its warm enough to start their growth period ahead of schedule, but the nighttime temperatures will halt (ie, kill!) any progress they make during the day. Common ways farmers choose to control these nighttime temps include installing a propane or electric heat system, installing underground pipes that send hot water to heat the soil from below, or using small heating mats underneath seedlings to ensure their safety when the moon rises.
Gary's heating innovation, also known as an opportunistic accident, is with corn chaff. This is a by-product of feed corn harvest, and looks a bit like cornmeal or grits. In order to produce heat, we start a small fermentation in the hoop by soaking this corn thoroughly and covering for around 4-7 days with tarp or plastic. Near the end of the week, the corn can be leveled into a 5" layer and topped with mulch, making a beautiful cozy cap between the still frozen ground and the heated bubble within our plastic hoop. Just opening and closing the doors gives air and temperature control from the still chilly spring winds, and our seedlings are happy until they're hardened off and ready for the wide and wild world.