Cod greenhouse

I am thinking of transforming my basement in a cold greenhouse to winter JM, metasequoia, olive trees and maybe bald cypress, species I cannot work with due to my hard winters.

Light will be provided by LEDs.

The temperature will be at 45 F
The issue I see is the place will be at a stable 45F with no variation.

Do you think this is viable

Thanks,
Manny

Having a cold frame / unheated garage / unheated basement will all work to protect less cold-tolerant species. However I question whether a stable 45 F will be cold enough to keep them dormant. It would certainly be at the high end of the range, particularly if your trees experienced colder temps before you moved them into their cold storage. I keep quite a few Japanese maples without any cold protection in average temps around 40F - 45F during the winters here... but we regularly see temps drop below 20F at night during cold snaps. It isn't the cold that kills, it's premature bud break in the spring followed by a late winter cold front that freezes the new growth.

Thank you for the feedback. I have no doubt that a bald cypress would die at minus 30 F. I cannot have my basement below 40 F for risks of frost of the plumbing etc.

Manny

45 is nowhere near cold enough. 40 or lower to 35 is better. The cold greenhouse I store tree in at professional bonsai nursery is taken down to 30-33 f for a few days in typically late Nov. then stabilized at 33-35 for the winter. They store subtropical species as well as cold sensitive species like camellia

Warmer and you will get early growth which won’t have enough light. It will get leggy and weak unless you have intense supplemental lighting. Your bald cypress willl likely bud in early Feb at 45

Thanks all.
Back to the drawing board

My bald cypress do fine in a cold frame and they get down to sub zero at times.

Frenchymanny said:

Back to the drawing board

Click to expand...

I suspect a modified cold frame would be necessary in -30... maybe dig a foot or two underground and line/backfill with heat-generating mulch, and then hopefully it's buried in snow all winter.