This sweetgum was not necessarily due for repotting this year. What prompted me to want to perform this chore was the behavior of the large root at the left rear of the tree. You never know what root(s) a sweetgum will choose to throw a lot of energy into. In this case, the one at the left rear took off, causing an unsightly upturn. It was just too strong, and that was the result in container culture. I knew the time would eventually come when it had to be addressed, but I needed to wait and gauge the strength of the tree before making the commitment. As you can see, there’s been a lot of growth. Knowing how sweetgum behaves, it was a safe bet that what was happening above the soil surface was reflected below. So today was the day.
The first step was defoliation. Any time you do root work outside of winter or spring, you have to take into account the tendency of the leaves to transpire moisture that can’t be replaced by a recovering root system. It’s common to remove the bulk of the fine feeder roots in any root-pruning session. We know they grow back, but we also have to bow to reality in that while they’re gone the leaves will suffer. So I removed all but a scattering of small leaves by cutting through the petioles. This is a similar technique to leaf-pruning maples: you cut half-way through the petiole, rather than try to remove the leaf and petiole together. This prevents damage to the axial bud that’s lying dormant in the leaf axil. If you stick with cutting through the petiole, you’ll find that in about a week’s time the petiole will fall off on its on, leaving the dormant bud undamaged.
Here’s a good look at the root mass. As I’ve mentioned before, sweetgums roots very nicely in a bonsai pot. You usually get few or no feeder roots when you collect them. The tree goes ahead and produces a tremendous mass of them in a confined space.
So I had no particular concerns about the health of this tree. All of these roots were healthy and whitish. No soft, mushy rotted roots. Exactly what you want!
Here’s the offending root. You may be able to see how it actually turns upward after emerging from the trunk. This is not exactly a desirable feature of a bonsai. In this case, the tree didn’t start off with this weird looking root; it just grew that way all by itself.
Here’s another shot of the offending root, after a good washing. Not exactly something you’d shoot for in developing a tree’s nebari.
So it gets whacked off and carved in with a knob cutter. Luckily, there were roots emerging from the bottom of this odd protrusion, so I simply cut off what looked ugly and was left with something I can manage going forward.
This is how it looks after repotting. Sweetgums heal very well, so this wound should close over in about four or five years. In the meantime, as it rolls over it’ll actually be a neat-looking feature.
And finally, the tree back in its home, a lovely Paul Katich oval. It should resume pushing buds in two to three weeks.
I’m planning a sweetgum collecting trip in a couple of weeks, so I should have new material for sale by mid to late June.