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irenebott

Zone 3 greenhouses

irenebott
9 years ago

Are there any Zone 3 greenhouse owners out there that could give me some pointers as to what works and doesn't as far as passive solar for winter months?
Any help would be greatly appreciated.
Some have pointed out that it may not be so easy to actually pull off the Full Passive Solar in my zone, and I do understand. I am hoping that I can "fit" my small greenhouse 12x8 with some rigid foil backed insulation to keep in the heat over night.
What has been your experience in retaining heat? I am using 6 mil reinforced poly ( double thickness)

Comments (8)

  • silentdreams
    9 years ago

    I live in 3b-4a with a greenhouse. I have been struggling with the same issue. We are going into our second winter with our greenhouse, last winter it froze solid, and I realized very quickly that I will not be able to run it in the winter without supplementing heat. This year we have made some additions. Radiant lines ran through the soil beds from our hot water tank in the house, a thick pool cover wrapped around and an electrical heater. The picture is from august. I try to get the most of my square footage :). I find every year so far has been all trial and error. Some things getting me an extra few degrees and some things getting me nothing at all.

  • hudson___wy
    9 years ago

    In the end analysis - you may come to the same conclusion that we have in our GH in zone 3 -

    You can economically and practically extend the growing season into the fall through November - Middle December and start the growing season in early March - with minimal cost using space heaters and timers or other supplemental night time heat to keep your GH above 40 degrees 24/7. But it becomes very expensive to heat your GH in Zone 3 from Middle of December to the end of February - with outside temps dropping as low as -40 degrees in Zone 3 as they do here! We shut it down during that frigid time of year! Also, it is kind of nice to have a break from the GH for a few months.

    Here are photos of our GH in late fall - October 15th and early spring - March 12th. We are successful in both late fall and early spring in keeping the plants above 40 degrees with outside temps as low as neg 10 degrees with very minimal heating cost.

    {{gwi:305535}}

    {{gwi:305536}}

  • karin_mt
    9 years ago

    Yup, agree with Hudson. We're in Zone 4, but it's swimming upstream to try to keep a greenhouse warm in the winter just for hobby purposes. A good, unheated GH is so productive from late Feb though November that it's hard to ask for much more than that.

    Good luck!

  • hudson___wy
    9 years ago

    Well "hi" Karin,

    hope you had a good GH year ! Did your tomatoes do well ? It was a fantastic year for Raspberries and strawberries - wished we knew how to duplicate it !! Everything else was great except a lot of our white onions grew awesome - then we lost them to mold during and after curing - it was an awfully wet fall. The yellow onions were OK though ! Please give us an update on your year !

    This post was edited by Hudson...WY on Sat, Oct 25, 14 at 22:07

  • karin_mt
    9 years ago

    Hi Hudson,

    Yes, we had an excellent garden year. We did a lot of soil improvement, both in the GH and in our outdoor raised beds, and that paid off. We also fenced our outdoor veggie garden, finally, so that made it so we got to eat the fruits of our labor, not the deer.

    The GH is still going nuts with tomatoes. I've been gone for much of October, so I'm behind in harvesting and canning, but I'm looking forward to catching up. We tried a new sauce tomato, called Granadero, which is healthy and productive but not as tasty as the San Marzano varieties.

    Sorry to hear about your onions, that is so sad after all the work was done. We had the best onion crop ever. Switching fertilizers did the trick I think because I didn't change anything else. Our potatoes still have scab though, so I guess we need to stop growing them?

    We also had a really lovely summer and fall, as I'm sure you did too. Hard to beat that!

    Jealous of your berries. We did not have good crops this year and I think I'm giving up on strawberries once and for all.

    I also wrote an article about the year-round greenhouse plan in an unheated greenhouse for Zone 4 garden magazine. Do you know that one? It's a magazine for the Rocky Mountain region.

    That's the news from here. Sorry for the thread hijack! :)

  • hudson___wy
    9 years ago

    My apologies too - Irene! Your thread is a good one - It always seems like such a waste to have a perfectly warm GH out there sitting in the winter with wonderful daytime temps on some of the coldest sunny days only to become an icebox when the sun goes down! We have made several attempts to utilize our GH over the winter - one attempt was to grow carrots. We thought we had come up with a vegetable that would tolerate the cold temps. The carrots took off OK but once the cold temps hit in Dec - Jan - Feb - the carrots froze with the soil and cracked badly - it didn't work for us - without heat. But if you can figure out a way to use the GH over the winter affordably - please experiment and share your results! It is fun to experiment and one learns so much in doing so.

    Thanks for the update Karin! Glad you had a great GH year. I am going to look up the magazine so I can read your article - what month. Is there an electronic version - of your article I mean - that you can send?

    {{gwi:305537}}

    This post was edited by Hudson...WY on Sun, Oct 26, 14 at 20:56

  • karin_mt
    9 years ago

    Hi Hudson,

    They don't post articles online but I do have a pdf I can email to you. My member page has an email link, so contact me there and I'll send it to you.

    BTW my carrots looked just like that too, but I found that the ones closest to the inside of the GH were usable, so now I just plant them in a single row along the central pathway. Most winters, it works. But your raised beds get colder than our ground beds, I bet.