Ken, I've never seen this before, but it was an unusually wet summer. I do like your idea to cut one and see if it will "root" for me.
It started raining again this evening. I'll have to go out in the morning to check the pots. If it were only one, I'd just think the pot had too much rainwater. I do have some really big pots also, but none of those seem to have the roots growing out the sides of the trunks. 'Just the three smaller pots.
