On Nov 23, 7:30 am, gonzo wrote:
I found there was a period of some weeks (2-5, depending on the
season) where unheated hoop house protected plants into the fall, and
gave me at least 4 weeks jump in the spring.

If you have an actual greenhouse, ie, glass/plexi, I suspect there
might be a leak somewhere. I routinely had air temps in the 40s in
the dead of winter (z5) when the sun was out, and I KNOW my doors were
not airlocked/air tight.

According to my "real property report" I have a portable shed/
greenhouse. That said, one side is glassed in with sliding storms on
each end. The green house and attached shed are normal garage style
construction and on a cinder block foundation wall. The green house
has slatted (2*4) floor over dirt. I can heat it, two infra-red heat
lamps (I really don't want to know how much it would cost to use
these) and an oil filled heater I bought for the house. There is a
fan that blows through a 3 in hole, I don't think it has a heating
element.

I don't want to heat it because then it would be cheaper to buy the
plants I need/want: 6 tomatoes, 24- 48 bedding plants, 20-30
geraniums. Not that I ever pay full retail

We just bought the house last year and I'm learning to use what I
have. Also, I have a cold frame (strawberry patch) and a supply of
storm windows.

Thank you all for your replies.