Heating the Greenhouse in Winter
What follows is 15 years of tried and true serious greenhouse heating and growing. We live in Michigan's Upper Peninsula, the most hostile place that I know for growing above ground vegetables. I have witnessed frost on my precious garden in July and complete ground snow cover in September. Most years our frost free days are between the end of May and the second week in October. But in all reality old timers have told me they have seen snow in every month of the year at one time or another. So to say the climate here is unpredictable could be a considerable understatement. We in Michigan's U.P. are at the mercy of the cold Canadian air catching a ride on earths jet stream deliberately gliding over the warmer water of Lake Superior. Together they form a dense cloud cover and enjoy a good laugh while they dump lots of lake effect snow on us. Absolute darkness comes at 4:30 in the afternoon starting in November and lasting until about the second week in February ....