Question
I am very interested in starting a small garden center form home. I live in zone five. I recently purchased a 20 by 20 quansat green house. Would I need to run heat to overwinter my containerized perennials or would they be ok without heat? Thank you, Kim

Answer
Kim,
It really depends on the degree of cold it reaches. When it drops below 20 degrees,I would put a heater on just to be safe.I wouldn't want to kill off my first stock of perennials.
It shouldn't take a lot of heat.Just a low steady heat so that the greenhouse is not warm,but not freezing.You don't want your roots to freeze. You can also insulate the pots with garbage bags tied around them.I used to do that for outdoor potted perennials.
Hope all goes well with your new garden center!