It's hard to get good pictures of these guys, but here is my "two trunk" tree that I kept in the basement this past winter. My basement has several tall southeast facing windows. That was the only light it got. I had a thermometer/humidity meter in the room that hovered between 60-80F. It turns out tall windows that face the sun heat up small rooms very effectively! Who knew
Humidity trended in the 40% range over the humidity trays. I usually let the grow bag sit in a shallow layer of water.
By end of winter, a few smaller branches had died almost completely. Even today some of the winter damage is still there on the old growth.
The shorter trunk on the left is last season's growth. Hard to tell from the picture, but there is new growth at the apex of that trunk and along a few of the branches. But not much
The taller trunk on the right is all this season's growth. The tree clearly favored the new trunk!
Larger/older trees are likely to have even more issues inside over the winter than my sapling did. They really do need cooler, more humid winters to rest in than is possible in most homes. But they also need warmer weather than winters are in zone 6. The coolest the one's in the garage got was upper 30F. Meanwhile, we had a stint of sub-zero temps here that I'm sure would have killed them outright.
