It is a left over from last season. Going through a terrible freeze in a pot killed most of the tree. I found no sign of diseases.Something is obviously weakening the tree, or else the top wouldn't have died. I would think the nature of the problem would dictate whether you touch the roots or not.
Normally a freeze is no big deal but that is the last straw after months and months of neglect and being root bound in a pot without much water.A freeze? All of my shohin Freeman's maples have frozen solid into blocks of ice at 10°F, and 100% woke up in spring without dieback. I'm not saying your climate and trees are definitely the same as mine, since your LA maples might be less hardy, but I think it would at least warrant further investigation to make sure that's really the cause.
You were right. It grew almost 5 ft already. Now I wonder if I can repot and do the root work before the second growth season down here.
Down here everything slow down in the super hot months of August and September. When it cool down a bit in Mid October, things grow again until the slowdown in early December. I know I have lots of bound circling roots in that pot and I am contemplating taking it out and put the tree in a grow box.Would that not slow down development? I find your climate interesting.
Does it look good as a deadwood feature?Repotted. Tree has a dead side down to near the root ball.
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Too early to tell for me.Does it look good as a deadwood feature?