Have new south facing greenhouse. New to greenhouse growing so reading reading reading.
Any helpful suggestions?
Hi redbran, South Dakota nice to know you are checking in with us gardeners here in UK. I'm sure some of us will have greenhouses in areas here where we get cold winters. I'm in Norfolk which is not normally too cold. You can insulate with bubble wrap and you can heat, as long as you have some air circulation at times to stop your plants getting mould you shoukd be fine. What are you most keen to grow? How big is it? Handy to have some staging to put some plants on ?
It really depends what you will use your greenhouse for and whether it is worthwhile or affordable to consider heating it.
Where I live we sometimes get temps down to -12 C, usually only for a day or two, though we have had it below 12 for 2 weeks. Most of the daytime temps are around or a little above freezing, colder at night and with wind chill to factor in. We do sometimes get fairly heavy snowfall (for the UK!), and drifting and the snow is actually good insulation, but if it persists for long, then plants will suffer from lack of light.
I use bubblewrap insulation - big bubbles are best - fitted inside the greenhouse and an electric fan heater with a thermostat set at frost free. The fan helps with the air circulation to keep grey mould at bay. It's a bit of a balancing act, as plants tend to survive cold better with drier roots, but this encourages the mould as they are not growing actively and the air is moist
This set up enables me to grow plants that would die in our cold and wet winters and to get an early start on seedlings for the spring, for both veg and flowers. I also grow some bulbs and tender plants for winter colour, though those needing more heat are grown in the house. My greenhouse continues in use in summer, which here is often grey, damp and cool, just to give vulnerable plants (and the gardener!) a more congenial environment.
From a quick read up, you have to cope with more extreme cold and heavier snow for longer, as well as icestorms and maybe tornadoes (!), and your greenhouse will be redundant in the summer. I hope your greenhouse is strong You may need to add some growlights and some shade netting or blinds for interim seasons to your list of requirements, electricity will be essential and an outdoor tap would also be useful. Good luck