I'm putting together a greenhouse, 10x13-feet base. Unfortunately it will be on a concrete-paved section of my backyard, and I know it will lose a lot of heat to the ground via conduction in wintertime. My goal is a 4-season greenhouse.
I would like to insulate the subfloor of the greenhouse to prevent heat loss via the concrete floor.
What is the best way to achieve this? "Best" meaning bang for the buck, and durable, and won't degrade over time due to direct sunlight, or being in contact with a frozen concrete floor?
Appreciate the help!