Early last September, I was helping a number of bonsai into the 5th US National Bonsai Exhibition in Rochester, New York. After taking care of several other trees, I picked up my entry, a Korean hornbeam, and brought it to a staging table just outside the door of the exhibit.
I’d planned to show the tree in leaf as I’d done the previous year at the Artisans Cup. Last fall, however, the foliage was looking pretty beat up, and I don’t think the tree belonged in the exhibit with anything but healthy, green leaves.
I quickly considered how defoliating in fall might stress the tree. If the tree started to leaf out after the exhibit – temperatures were still warm in California – the new foliage wouldn’t have enough time to generate the reserves necessary to produce an additional flush of growth the following spring.
If I could keep the tree dormant through fall temperatures in the 70s and 80s, the tree would get a longer dormancy than it usually does and spend its reserves on a flush of spring growth.
Boon Manakitivipart was nearby and I asked his opinion about how safe it would be to defoliate the tree early. He figured it was probably OK, the same conclusion I’d come to.
After making a quick decision, several helpers and I plucked the leaves and brought the tree into the show where it was shown in its winter silhouette (see “Deciduous Bonsai at the 5th National Bonsai Exhibition” for a photo).
By the time the tree made it back to California, a few shoots had opened up and the buds appeared to have swelled. I placed the tree under a bench against a fence to keep it as cool as possible.
Fortunately, the buds stayed closed until this spring when they emerged all at the same time. Here’s what the tree looks like now.
Korean hornbeam – late March
The only difference I noticed this year was that more buds had sprouted from the trunk than usual.
New shoots emerging from the trunk
I removed these shoots, and left the rest of the tree alone.
After removing the shoots on the trunk
Korean hornbeam – ready for spring
At this point I’ll let the tree grow freely until May when I’ll do some thinning to make sure light makes it into the tree’s interior.
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Charles Orr says
Beautiful tree Jonas. My Hornbeams are the last of my deciduous trees to come out of dormancy. Is that typical? The Maples come out almost a month earlier.
Lars Grimm says
I have the same thing. My hornbeams in NC still haven’t come out, but my maples are in full leaf.
Jonas Dupuich says
Thanks Charles! Yes, they typically come out on the late side.
Charles Orr says
On another topic. After our pine seedling workshop last weekend, I came home to review my copy of Bonsai Today. I have issue #20. But then I couldn’t remember the instructions that you told me not to pay attention to and why. Was it in this issue, or in #7 that you said not to follow? Thanks.
By the way I soaked the seeds Mark gave us and 92% were viable! Looking forward to sowing this weekend.
Jonas Dupuich says
Issue #20 is the good one. Issue #12 shows an approach that creates more scars on the trunk.
Good luck with the seeds!
Andrew Robson says
Glad to hear it stayed dormant! Have you ever experimented with DynaGrow’s Protekt in your area? I suspect it might help with the browning of your leaves.
Jonas Dupuich says
Thanks Andrew! I haven’t tried it yet, will look to give it a try this year.
Mauro Daniele says
Jonas, would you say the longer dormancy was “beneficial” for the tree? Sounds like you got some extra vigorous sprouting.
Jonas Dupuich says
Good question Mauro – I don’t know that it was beneficial, but am happy it didn’t appear to be too detrimental!
Jorge Rossette says
Hi Jonas,
How you promote backbuding and ramification in your Korean Hornbeam? What techniques you use and when?
Jonas Dupuich says
Good question Jorge – very simply put, fall cutback and partial defoliation are the key techniques for developing branches on hornbeam. You can find more info about each in previous posts.
I hope this helps!