Repotting is different than typical bonsai styling because the amount of time one gets to see and work on roots is so short and infrequent; quite unlike the rest of the tree that we contemplate each day.
However, root work will make or break a bonsai. For that reason, and the fact that I have a horrible memory, I make it a point to photograph my bonsai as I work on the roots. This allows me to make a plan, and (more importantly) helps me remember that plan during the next repotting session!
Here is a quick look at developing a Japanese Maple’s nebari, over the last 3 repottings.
First, 2008 (third repotting)
Looking back at this, 4 years later, I would have cut each of the heavy roots back at least as far as I cut the left two roots shown above. They are thickening well, but it would have been better to get the ramification closer to the trunk. I also would have removed the lower root on the right (at the 5:00 position) , where it’s fused to the root above. Now it’s become a feature.
2010 (fourth repotting)
Combed out, trimmed back
Washed out, and further reduced
Close-up. Note the root at the 7:00 position was shortened in ’09, and new roots are growing well from the cut. Rooting powder was placed on cuts to encourage new roots to grow in the gap. They did not appear.
2011 (fifth repotting)
This year, the repotting was less invasive (mostly due to the fact it was done as a demo), but the roots were still combed out radially and shortened. Tertiary roots are starting to thicken. See why I wish I’d have cut the main roots back shorter?
2012 (sixth repotting)
Combed out and shortened.
Hosed, combed and shortened further. Notice the tertiary roots are thickening and maturing.
Close-up of roots, some thick roots were removed, just like branches to keep movement and taper.
Because no heavy roots remain, the fine roots are arranged in radial direction, then bamboo sticks are laid across the fine roots, and anchor wires are tied over the sticks to hold everything down. The gap in the center is still troubling. Fertilizer cakes were packed into the gaps right up to the trunk, and fine feeder roots did develop there, but they didn’t originate from the location. The goal is to either have the existing thick roots finally fuse, or continue working to develop fine roots that will knit together over time.
After. The tree was potted slightly higher this time to start to expose the tertiary roots and allow them to mature and thicken.
Thanks for looking!