Thank you Tiffany! If I understand correctly, I can use the hardiness zones to determine minimum required by taking the highest listed zone number and using the top end of that range. Thus, if a plant is listed as Zone 4-9, then it would probably need a minimum of 30 degrees F.
However, at some point that seems to break down. Many commonly used indoor houseplants are listed as Zone 10 with a 30-40 degree minimum temp range. Yet, we know they do just fine all year round in 70 degree indoor temps.
