When I saw the young maples growing in Kazuo Onuma’s garden, I immediately wanted to give his techniques a try (see “Onuma’s mini-bonsai growing techniques” for details).
I picked up some bare-root liners – young trees created for the nursery industry – and planted them in 4″ pots. By spring, all were growing well.
My plan was to let the trees grow all year before making any big cuts, but I became curious about how to take the next step. Specifically, I wondered how old the trees needed to be when I made the cut, what time of year was best for making the cut, and how low on the trunk I could cut.
I decided to cut half of the liners back in July to see how the trees would respond. And although the approach wasn’t scientific, the results will definitely influence my next round of experimentation.
Here’s a photo of twelve trident maples before and after pruning in July.
Trident maple liners
Trident maples after pruning – July, 2020
Low cut on a trident maple
I’m used to tridents sprouting wherever I prune them, but I’d never tried pruning so severely or on such young trees.
I took a similar approach with a dozen Japanese maple liners, but I took care to leave at least one healthy bud on half of the trees.
Japanese maple liners
The lowest visible node
Pruning just above the node
Japanese maples after pruning – July 2020
What I’d hoped was that the young trees would produce new shoots very low on the trunk, much like I’d seen in Onuma’s garden. Here’s what happened.
The Japanese maples that were cut down to a healthy bud or visible node responded well. The others produced no growth at all.
Japanese maples two months after pruning
Of the twelve Japanese maples I pruned, seven grew, and the other five failed to produce a single bud. Of those that grew, half produced two shoots, and half produced one shoot.
New shoot on a Japanese maple
It was a similar story with the trident maples, but because I cut all of them below the lowest visible node, none produced new growth.
Trident maples two months after pruning
I’ll leave the trident and Japanese maples that have yet to sprout in the garden for a while longer, but I have no expectation that they’ll start growing.
The lesson seems to be that young trees need at least one healthy bud to produce a new shoot. Would waiting for the trunk to thicken make a difference – or would pruning at the start of the growing season help? Maybe, but I’m less interested in these questions than in simply pruning down to visible buds to get these trees started.
Of course, I know very little about the next steps of the process either, so I plan to let the trees that lived grow for the time being while I find more liners to work with next year.
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