I’m starting this series on cork oak with the second step – reducing branches that are too long or too straight. The first step is repotting the tree into bonsai soil and generating healthy roots.
Last year I repotted this oak in a training pot after nearly bare-rooting it. The field soil supported few roots so the old soil mostly fell away during repotting. The tree responded well to the repotting and grew well last year.
Cork oak
The tree is now ready for initial cutback. I don’t plan to use many of the existing branches as most are long and straight. In an effort to get the tree to produce new shoots, I reduced all of the long and straight branches.
Straight branch
Reducing the branch
After reducing the branch
I expect that new buds will appear on some of these shortened branches which will help develop better branch structure. Some stubs may dry out and completely die back. Both options are fine as I expect to create most of the future branches with new shoots.
Here’s what the tree looked like after cutback.
After cutback – 27″
I plan to let the tree grow freely through spring. When new shoots emerge I can start to add shape by wiring them before they grow too large to bend. The timing of the next cutback will depend on how quickly the tree grows. I expect this will be in spring or fall.
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David says
Hi Jonas, I live in coastal San Diego and these trees grow great in my yard. The property behind mine was a Cork Oak farm back in the 30s. I have one urban yamadori in a bonsai pot. I used Akadama, pumice, scoria and kanuma. I had heard that Cork Oaks need kanuma for the acid retention. The water where I live has a PH over 8, so chlorosis can be a problem. What soil combo do you use? What soil combo do you recommend I use?
Thanks,
David
Jonas Dupuich says
Hi David! Good question. My oldest cork oak was developed in Southern California and is possibly 50+ years old. During that time no kanuma was used. Likewise my second oldest cork oak. I’ve experimented with kanuma in oaks and cork oaks but it would take a relatively long-term, and likely controlled, experiment before I could say one way or the other about what soil works best. I can only recommend using whatever people in your area have had the best success with over long periods of time. Beyond that, I’d fall back on basic volcanic mixes with akadama and pumice and/or scoria. And if you have kanuma, feel free to try some of that too!