What temperature do you set your Greenhouse to for winter?

Hey Everyone!

Just wondering what temperature is best to set my greenhouse to for my electric fan heater to run at during winter? I currently have to set to 6 degrees but haven't insulated it yet as I'm doing it this week.

My solar battery for the house usually runs the entire house easily every day but isn't lasting till the evening lately so wondering if the greenhouse heater and conservatory heater (15 degrees) are sucking the life out of it.

 

Like Shiney I don't heat my greenhouse. It stays dry in there as it is built on a mound of rubble topped with gravel, this also tends to absorb heat on sunny days and then release it at night.
Tenderish plants that go dormant are kept very dry over winter, similar plants that remain in leaf get a minimal amount of water. I take cuttings and overwinter these in the same greenhouse and on cold nights these get covered with fleece and or newspapers.
I am also fortunate in having a fairly mild climate.
Where in the UK are you @PhilC at a minimum of 6°C a number of my plants would try to grow and struggle with the low light levels. It really depends what you want to keep in the greenhouse overwinter. Anything tender could be moved to the conservatory. Interesting 15°C is the temperature at which my central heating comes on in the house and 18°C is when it goes off if I have switched it on in the evenings.

 

We don't heat ours either. We do have a fully enclose double bubble wrap framework setup that shuts off one half of it and really tender over winters get housed in there with additional fleece added if and when needed.

 

My greenhouse is more about survival than growing this time of the year, so mine is frost free only, the aim is to get the heating to come on at around 1 or 2c and raise the temperature only a couple of degrees before shutting off.
I doubt my heating as even come on this year yet.

 

It depends what you've got in there.

 

I grow little that is delicate so do not heat through winter. Do have equipment that could, which will be operational if required, support new sowings early in the new year. Fuschias and geraniums take their chance inside without heat, 85% probability to survive in this coastal zone.
Contemplating creating a warm(er) inner zone within new greenhouse, but this will be for next year.