During college I served as a volunteer for the American Bonsai Society (ABS) for several years, mainly editing articles and writing the ABStracts column. During that time period, I was fortunate to visit the beautiful Oregon Coast town of Sweet Home and interviewed one of the owners of Cascade Bonsai Works, Dan Zwierzyna, with the intent of writing and publishing an article for the ABS Journal. At some point after my visit, the nursery unfortunately closed, but their material was purchased and made available by Wee Tree Farm. It was at Cascade Bonsai Works that I encountered my first Oak Leaf Hornbeam.
I have always admired Carpinus as followers of my blog know, so I was especially intrigued by this rare form of European Hornbeam. It was labeled Carpinus betulus ‘Quercifolia’ at the nursery, but my recent research indicates it is now referred to as Carpinus betulus ‘Heterophylla’. I had originally purchased several larger trees from Dan, but eventually sold them during a time that I wasn’t akin to having any trees larger than chuhin size.
I was fortunate to acquire one again in 2010 from Wee Tree, although I have never seen the leaves on this tree revert to the oak like structure, as I saw on a few of the specimens at the nursery. I’ve been told that the oak like leaves on this species do not form immediately and generally come with age, but I have yet to see any on this tree. They do turn brown and hang on to the tree during dormancy, similar to many oaks, but this is also a characteristic of many hornbeams. I purchased it with the intent on air layering the top, unsure as to what may come of the bottom portion.
My first attempt in 2012 to air layer this tree was unsuccessful. Upon inspecting the location of the layer last year, there was a slim portion of the cambium – no more than 1/8”, that managed to successfully transfer enough nutrients to keep the top section alive on the existing root system. This year, I used the same location, paying special attention to removing all signs of living tissue and girdled the top portion of the layer with wire to further discourage the cambial tissue from forming again.
The layer was successful and removed in September of this year. I plan to further develop the bottom section, possibly in the broom style.
By the way, that article was published in the NBS, but the wrong author was listed, believe it or not. I’m sure that person has gone on to have a successful writing career!
The tree in 2010
The tree in 2013
The air layer
I will post some photos of the potted layer and bottom tree once dormant. We are experiencing a long, warm fall here in southeastern Nebraska and many trees are just turning.