A few years ago I bought a large live oak tree from super-collector Tim Kong. It has a nice root base and two trunks, one of which splits a little above the base into two smaller trunks. The architecture of an oak is so far removed from that of a traditional bonsai shape that I cannot even begin to comprehend styling one with a first branch, second branch, back branch structure as is taught in many books. Nor can I contemplate styling it with distinct levels of foliage progressing up and outward as is common in multi-trunk arrangements.
The common natural shape of an oak resembles in some way the shape of a water fountain. The main trunk or trunks typically come almost straight up out of the ground and slowly head outward, each little twisty section heading up until it starts heading out and finally the smaller branches head back down again. For a bonsai-ist this makes things easy at the outset and more difficult as the tree becomes more refined. The branches should be wired upward if they are coming directly out of the trunk. The tips of the branches, once the tree is nearing completion, except for the middle of the crown, should be heading outward and down toward the ground. The main branches should also be quite a bit larger than on many other trees since they are, in most cases, simply sub-trunks. A large trunk with tiny branches coming out of it is only seen in oaks in the case of fire damage or other catastrophe and is contrary to the normal look of the tree. In many respects the oak form closely resembles broom style but the main branches do not usually exit the trunk all at once.
Styling an oak to look like an oak takes some persistence and some neglect. The branches that you bend down will become weaker at the tips, sprouting back and heading up again. Bending them down repeatedly will give the branches better movement and will create a series of arches that should become smaller as they approach the outside of the canopy. Oaks do not have a single crown, but are instead like a head of cauliflower with many bumps making up the overall canopy. The character of these bumps and negative spaces in between them is harder to create than a traditional pine branch structure. In fact, it is better if the trunks as they split off and become limbs and smaller branches look almost random in arrangement. Too much time spent trying to design this part of the structure will result in a less natural look. If you are raising a tree from a seedling you should neglect it and allow it to go wild for a while, then cut back and wire, and follow with a period of wild growth again. All this will lend a more natural feeling to the tree, whereas too much cutting and designing will lead to a simplified structure lacking depth and character.
I’ve now spent about ten hours putting wire on my oak this spring and I still have part of the crown to wire. I wired it after it’s initial growth last spring, putting movement into all the major branches and bringing them into rough position. This year I am concentrating more on the finer structure that is developing, adding bends to the small twigs; distributing the leaves evenly and starting to create those bumps of the cauliflower.
Look for our August guest speaker, John Thompson, to enliven your imagination more on the topic of oaks. John has a lot of great tips on how to grow and style oaks and will be sharing them with all in attendance.