I currently live in northeast Ohio in zone 5. I am going home to the Bay Area, zone 9, in mid January and would like to bring back several Cryptomeria japonica 'Elegans'. I grew these from cuttings made in early spring of 2007 and now they fill 1 gallon containers. My plan is to move them up to a 3 gallon container in April and then plant them in the fall. My question is how do I successfully move potted plants from the land of endless sunshine to a frozen hell like this during the middle of winter?

Here are a couple of ideas. Feel free to critique them and/or add your own suggestions:

1. One of my bedrooms is not heated and has windows that face east. It probably gets down to 40 F. in that room. What if I put them so they get maximum light and just keep them watered until March at which time they would go outside?

2. I could build a mini "greenhouse" on my sunny back deck out of 2 x 2s and clear plastic. The 1 gallon pots would go inside of a 3 gallon container with sawdust to make up the difference. I'd probably put a heating cable inside the "greenhouse" to keep it a bit warmer.

If you have any experience growing this tree in such a climate I would sure like to hear from you. I saw a couple of C.j. "Yoshino" growing at OARDC in Wooster and they looked pretty healthy to me. Absolutely fantastic tree if you have never grown it. Turns sort of purply-bronze in the winter and the softest foliage you can imagine. Not affected by much of anything and needs no pruning.

Thanks for your help.

Rolf