What can I expect from a GH

Hi All, Love DG.
Will be relocating to the Wilmington area of North Carolina (Leland) zone 7B and considering purchasing a GH. Aside from starting veggie and flower seeds early in the year, can I over winter some of the not so hardy plants ? Will that require a heat source. If so, whats the most economical way to go?
Thanks
TimSki01

If you want to overwinter tropicals then you will need a heater. But if you've just got a few things that would be borderline in your zone and you want to give them a little better chance then you could probably get away without it.

I'm zone 5, and without a heater even my borderlines would be goners. I have it set to keep the GH (8x8') at 50 degrees. I add bubble wrap to my walls and ceilings and have caulked joints for better sealing. Water buckets line my north wall. My north wall is covered on the inside with 3/4" styrofoam. With all this the heater doesn't run too often and our electric bill didn't go up despite a very cold winter last year. When I start my seedlings, I turn the heater up to 60, but with sun during the day, again the heater doesn't run very much.

I have a 8X12 greenhouse here in zone 4 and I just finished bubble wrapping walls & ceilings. I can feel the cold from off the floor though. Decided to over winter lots of plants but am wondering cathy4 what kind of heater would u recommend that is electric. My GH is between garage & two story shed so I dont get the north wind much on one long wall and the south long wall is sunny. any tips would greatly be appreciated.

My son suggested a milkhouse heater. It has a sensitive thermostat and can be set to turn on at a lower temp than those for your house. I paid around $30 for it. I have it sitting about a foot off the the ground, at one end of my GH and the fan blows gently toward the other end. We had a very, very cold winter last year and everything made it through.

Sassy, my GH is 8x8, on a slab and gets wind on all 4 sides depending on the weather. It is in the coldest part of my yard. I do have it caulked and partly bubble wrapped (on the north and east sides, plus the roof.) I don't know for sure if it would be enough for your situation.

I have been reading about greenhouses, and one thing that seems to help with the heating (from what I've read) is to close the north and west walls, leaving only the south and east walls glazed. Then fill black 55gal drums with water and place inside opposite the south wall. The sun heats the water, forming a heat sink, which radiates warmth back into the greenhouse.
The problem I can see for me would be cooling it in the summer. Here the summer days/nights routinely get 100/80 deg. and with 40%humidity, so evaporative cooling wouldn't work.
Haven't built a greenhouse yet, I want one for tropicals.
Any suggestions would be greatly appreciated.

In a climate like TX it'll work best if you take the plants out of the greenhouse during the summers. I have a GH that I use for overwintering tropicals, but during the summer I pull everything out and display the containers around my yard. Unless you're running a big commercial operation where it's not realistic to move all the plants out in the summer or have really huge plants that are impossible to move, it seems like more trouble/expense than it's worth to invest in cooling for it.

We take everything out, too, in summer. It gets really, really hot inside even with ventilation. For me a GH is 3 seasons, not summer. It is great in the winter to go out to the GH and sit in the warmth, smelling the plants and playing in the soil.

Thanks for the info, I have an area that I am thinking of converting into a greenhouse, maybe a good project for my son.

I can see your point about the cooling expense. I will just get dwarf varieties of the tropicals and move them in and out. For now, I think I will read and plan more and wait until next fall to start the greenhouse.

cathy4, I have my picnic table up in my greenhouse. Lovely to have a few girlfriends over for lunch in the middle of January when it is green and things blooming up there.