Defoliation of American Hornbeam Forest
This Carpinus caroliniana forest was made in the Spring of 2013 and this year it was defoliated for the first time. Owen Reich told me that American Hornbeam respond well to defoliation (maximum once per year) and indeed the results were positive. One issue I noticed is that as the second flush was coming in, some very vigorous leaves grew back at an accelerated pace and became very large. These were periodically removed to allow the smaller, less vigorous leaves to fill in at a more uniform pace.
The tree was defoliated May 31st, just after the new growth had hardened off. One month later, the second flush had filled in and hardened off.
May 20th, ten days before defoliation (I forgot to take a picture right before defoliating the tree). The leaves here are not quite hardened off.
May 31st immediately following defoliation.
The tree today, just over one month after defoliation. One major effect of defoliation was that the smaller interior shoots were allowed to open up. Many did not open up at all in the spring as all of the vigour went to the shoots of the exterior canopy. After defoliation, the density of the tree is much more uniform.
The new leaves are about 50% the size of the old ones. Very nice!
American Hornbeam Forest Update
This forest was assembled almost exactly three months ago. It began to flush out nicely but then developed some health issues – the leaves were damaged and discoloured, and the new growth was weak. It was definitely not a pest issue. I am pretty sure the problem was a pH imbalance brought on by the moss I covered the soil with. Well, not the moss exactly, but the grey stone dust in which the moss was growing (it was collected from a gravel lot).
Who knows. I was too lazy to actually research the issue, and the tree never really seemed to be fatally ill. Whatever the problem was, it went away and the tree has been growing strongly for the last few weeks. Unfortunately the earlier problems kept me from cutting back the spring shoots, which means the tree is already behind schedule in terms of ramification development.
Today I cut off all the ugly damaged leaves and cut back the growing tips. I think complete defoliation may be appropriate for this species but I am still just getting acquainted with it, so maybe next year once I have a better feeling for what it is capable of.
Damaged leaves.
After leaf and shoot cutting. Damn birds been in my moss. I live in a treeless cookie-cutter suburb so squirrels are not a problem. But man, there are birds everywhere.
Sticks in a Pot
Like many bonsai enthusiasts, I am obsessed with old, collected trees. For several years I have been heavily biased towards collected material and still am today – nothing (well, almost nothing) excites me like a stunning piece of yamadori. Nevertheless, I find that wild material almost always lends itself to a dynamic, survivalist image. If I were to fill my yard with this material only, I would have a pretty monotonous bonsai collection. Already my collection is lacking in delicate deciduous trees (nine years of bonsai and I have never had a japanese maple!).
I was recently inspired by an article in Bonsai Focus #120 entitled Easy Does It, Forest Planting by Nobuyuki Hirose (see the preview of this issue here). In this article Mr. Hirose and his apprentice use young beech and hornbeam seedlings to create simple yet elegant and attractive forest plantings. The careful selection of the material and design of the planting made these “sticks in a pot” into something special.
Armed with these images in my mind, I visited my friend Andrew who works at a gigantic (read: millions of plants, literally) wholesale nursery and picked up a trunkload of American Hornbeam (Carpinus caroliniana), American Beech (Fagus grandifolia), and European Beech (Fagus sylvatica).
Today I made a nine tree forest planting of American Hornbeam. This species grows locally, although I have never found one worth collecting (most people who collect them trunk-chop them drastically, thus creating a long-term project). Like most hornbeams, these have fine twigs, smooth bark, and small buds – things which are useful for a small group planting that is best appreciated in winter.
Hornbeams. These are all in one gallon pots, and roughly three years from seed. I tried to select a range of trunk sizes with gentle movement and lots of twiggy branching.
In addition to the normal screening, some 1/2″ galvanized steel mesh was tied down to the bottom of the pot. This creates as many tie down points as one could ask for, thus making it relatively easy to fine-tune the placement of the trunks.
The cream coloured pot is by Yamafusa. I think a light blue pot would have been better, but this was what I had on hand.
Every tree was more or less barerooted and at least 80% of the roots removed. These trees were not prepared for bonsai, so each one had a massive taproot, roughly the same thickness of the trunk.
Before pruning/refinement.
Final image. I need to keep on top of the cutting this season to ensure that I don’t lose the delicate twigs. I would like to shorten the main tree by a few cm, but currently the necessary branches don’t exist.
Side view.
scale