As a general rule, we become interested in bonsai because we’ve either seen photographs of fully trained specimens or we’ve seen them in person at a bonsai show or arboretum. Put another way, we’ve seen them at their best, trained, trimmed and groomed for photographing/showing. But when we move beyond bonsai observation into bonsai growing, we have to come to a realization that it is not in our trees’ best interest to remain constantly in show condition. To be sure, we spend a lot of time styling our trees and maintaining those styles … however, our trees do best when we let them grow out from time to time.
This is my “root around cypress knee” Water-elm, Planera aquatica, whose progress you’ve followed for a while now. I repotted the tree earlier this year. This is another occasion where a bonsai must be allowed to grow unrestrained for a while. Repotting tends to encourage growth. This is simply the tree trying to reestablish its metabolic balance. After the roots are pruned, which usually occurs during bud swelling in the spring, the tree will continue pushing those buds into new shoots. Root growth will follow this round of foliar growth, and it’s supported by the food, hormones and other compounds manufactured by the leaves. Pinching or pruning at this point tends to dampen this production and can set back your tree. So it’s best to let the tree grow out, untrimmed, for a while.
Here’s a perfect example of this type of benign neglect I often write about. I’ve done nothing to this water-elm since repotting it. The strong shoots are now over two feet long. And I know that I’ve gotten strong root regrowth, so it’s time to prune this tree back to its design shape.
This work goes pretty quickly once you’ve had enough practice. In addition to pruning to shape, I’ve taken out the crossing branches and any growth in the interior of the tree that doesn’t belong. Now I leave it alone for another round of growth – water-elms love summer, so I’ll have to trim again in another four to six weeks. And next year, I’ll prune this tree back much harder in order to take it into its next stage of development.
Here’s another example of this care technique, my late friend Allen’s Crape myrtle, Lagerstroemia indica. This tree is due a root-pruning but I’ll probably leave this chore till next year. Regardless, I’ve allowed it to grow out unrestrained – so much so that it’s put on flower buds. Most of them are going to go, however.
And the result a few minutes later. This tree also needs a harder pruning, along with some minor design work. It’s gotten somewhat overgrown and needs to be brought back in some. But for now, it looks a good deal more tidy, don’t you think?