Examples of year round growing in unheated greenhouses?

In the early stages of designing a greenhouse for myself, I'm trying to gather various examples of greenhouses with track records in climates similar to mine or more challenging. I'm at 42.5 N latitude and 3700' elev.... in a 6a zone.

My goal is to grow year round, traditional veggies and fruit... WITHOUT supplemental heating.

After attending a greenhouse design workshop in the Colorado mountains where all manner of veggies and fruits were being grown (I ate freshly picked figs while pruning banana trees) at 7200' elev in a 4b zone with no supplemental heating, I was sold on that design. That design method is referred to as "climate battery" or "SHCS" (Subterranean Heating and Cooling System).

(side note: I attended the workshop partially due to a client wanting me to design one of these greenhouses for her. Unfortunately, her plan changed and I didn't get to use her as my guinea pig) ;-)

That said, I would be very interested in hearing/seeing what other designs have proven to work for people who are growing similar crops in similar climates without auxiliary heat. Of course, I would love to hear about those using the "climate battery" design as well. I am less interested in theoretical designs given all that can be found on the Net. I would like real-life and preferably long-term experience and numbers... even if they were not success stories.

Anyone?

Thanks,
rusty

Hey Rusty, may I suggest the book Four-Season Harvest by Eliot Coleman. He has been doing what you're asking about using cold frames and unheated greenhouses where he lives in Maine. It is an excellent book that I believe thoroughly covers the topic and offers a wealth of information, ideas and techniques to garden year round. Hope this helps!

James Freyr wrote:Hey Rusty, may I suggest the book Four-Season Harvest by Eliot Coleman. He has been doing what you're asking about using cold frames and unheated greenhouses where he lives in Maine. It is an excellent book that I believe thoroughly covers the topic and offers a wealth of information, ideas and techniques to garden year round. Hope this helps!

Thanks, James! I actually have that book. It is where I learned how to harvest salad greens throughout the winter. As I recall though, his greenhouses were more conventional and he didn't use them for growing fruit... and I think the veggies he was growing in them required a second covering for protection. That said, it has been a while since I've had that book open. I'll have to take another peek. Thanks again for the recommendation on an awesome book!

rusty

I am in zone 6.  I do a pretty good job with composting straw in my high tunnel and 200 gallons of water for passive solar.  Even so, I need supplemental heat in Jan and Feb.

Here is one with comparisons and numbers. https://threefoldfarm.org/consulting

Are you looking for totally off grid or will you have grid power for fans and such (you just want to avoid buying a tanker of propane every year)? There seems to be a difference in design to think about--grid tie is much easier to pump the heat out of the storage.  

Are you looking at rock, dirt, or water as the mass or a combination?

R Scott wrote:Here is one with comparisons and numbers. https://threefoldfarm.org/consulting

Are you looking for totally off grid or will you have grid power for fans and such (you just want to avoid buying a tanker of propane every year)? There seems to be a difference in design to think about--grid tie is much easier to pump the heat out of the storage.  

Are you looking at rock, dirt, or water as the mass or a combination?

Holy smokes.... there's heaps of valuable info on that site! Just what I was hoping to find. Thanks much for that!

As to your questions, my new place will be on grid. And you're correct: I don't want to be paying for or burning a bunch of propane. As far as mass.... it will likely be mostly if not all dirt... but with a fair bit of rock on site, I could incorporate that in as well, depending on the design.

rusty

I have a couple years into growing in my greenhouse.  It's been unheated since my compost heat system didn't work.  Due to that it gets down to 20 in the dead of winter (I'm in zone 4a with -20 to -30 for worst case low temps outside).  I had cabbage and broccoli grow slightly through the winter this year.  I'm sure I could've grown more stuff if I tried but I was disappointed at not staying above freezing so I didn't do as much as I should've.  

If I had sun for more than 10 days a month in the winter I'd do better with this design.  Here's my thread:  https://permies.com/t/76165/Mike-passive-solar-greenhouse-design

The one yard revolution YouTube channel has a lot on growing through the winter with unheated green houses in zone 5.
They still focus on winter hardy greens,  but there should be some applicable information.
Here is a play list:

https://www.youtube.com/playlist?list=PLApXYvbprElwtRHz0l63gp6ZsoM-BvdmM

How are you getting along with your greenhouse Rusty? This might be useful if you haven’t already completed it https://youtu.be/pXPakvPzgpE

Megan Palmer wrote:How are you getting along with your greenhouse Rusty? This might be useful if you haven’t already completed it https://youtu.be/pXPakvPzgpE

Thanks, Megan! I skimmed through. Will take a closer look when I get more time.

I have not started a greenhouse. Figured I'd focus on building my house first. At the rate I'm going on that though, it's going to be a while. 🤔