Sometimes the roots are in bad enough shape that sharp intervention is required. This tree was growing in organic soil, and I didn’t do a good job of removing it in early repottings. This led to weak roots under the trunk, and rotting roots coming off the trunk itself (potential nebari).
The outside of the root ball shows plenty of microrrizae:
But under the trunk, I was finding lots of black, rotten roots and dense black field soil. So using big concave cutters, I started to clean up the underside of the trunk, back to only what was alive and not rotting:
It was a gamble, but I was convinced the tree would continue to decline if I didn’t get aggressive. In the end, I removed more than I would like on a Japanese Maple, let alone what I’d want to remove from a JBP.
However, I had left a lot of foliage on the top, and the timing was about perfect, buds were pushing, and the sun was warm.
It’s planted a bit high in a shallow pot, which was intentional to get better roots growing along the surface. The depth will be adjusted in the next repotting, as well as the planting position.
2 months later; late May, I am satisfied with the tree’s response:
I will not candle-cut it this summer, but will prune and wire it in the fall, and reposition the tree in the pot in the spring of 2022.