Overwintering Mikawa Yatsubusa maple.

[Cactus Willy]

Do I leave my mikawa outsirde in zone 6 or bring into attached unheated garage in winter. It is in 12" by 12" by 20"tall thick rubber pot.

 

[Arlithrien]

I'd say it should be fine outside. Palmatums are pretty cold hardy, subtract 1 zone for potted plant and it's zone 6 hardy. If I recall correctly mikawa yatsubusa is a relatively hardy variety too. I'd recommend putting it on the ground at least and just incase i would surround the pot with some leaves.

 

[Hack Yeah!]

Welcome @Cactus Willy , let's see a picture of your tree? I'm in a warmer zone but prefer to leave my trees outside and let nature help me sort them!