Good day all! I need some help for the upcoming season. I have acquired many new trees (I have been bitten by the bug) of the pine variety. I am have around 200 pine seedlings along with my other older trees and need some more room for overwinter care. I live in Canada where the climate is vey warm in the summer (up to +30 degrees Celsius) and freezing cold winters (down to -40 degrees Celsius). With bonsai, this provides quiet the challenge. This winter, I had put my trees in my unheated garage that stays about -9 degrees Celsius which is about perfect for my conifers. I unfortunately am out of room in my garage and am looking into getting some "real estate" for the trees to keep them save from root damage one winter. I will put the trees outdoors in the summer but simply need something to rid the downfall that -40 degree temperates will have on my trees.

I have been looking into building my own greenhouse and was wondering what it should include to ensure adequate tree health. Does anyone have experience keeping trees alive in greenhouses amidst my volatile climate? What should I do about ventilation? Should I heat the greenhouse? If so, with what? If anyone has any insight, please feel free to enlighten me! I would be glad to hear from you. Thanks in advance,

Haden

The best resource for overwintering trees in Canada in greenhouse is nigel saunders on Youtube.

I live in sweden, not as cold as in Canada and lot less snow or sunshine in winter. I keep my trees in greenhouse in winter mainly to protect them from too much rain in winter. Also some late winters when sun gets back the soil is still frosen. Strong sun and frosen soil is a tree killer. In the greenhouse some days the soil thaw and the trees gets a drink. Some years i still need to shade the trees for best care.

My few suggestions based on my experience and my climate:

Build the biggest possible within your space or budget limits. Collections tends to increase in size.

Shoose polycarbonate before glass, gives more stable conditions.

Make space for a small heated overwintering room. Very handy if you want to grow some less hardy trees or if you want to protect a recently styled tree from frost.

Consider temperature controlled hatch openers. Very good for the summer.

Plan flexible solutions for benches. In the summers you might want to grow something else in there.

A small working bench is really nice as well as a small seating area to relax and enjoy the trees. Again, flexible, so they are only there when you need it.