NABF Newsletter #2

Feature #7

A NEW TRUNK CALIPER REDUCTION TECHNIQUE
Creating flattop bald cypress bonsai using collected,
large caliper, stubbed off trunks

By Vaughn Banting

Those of us who collect bald cypress from the wild usually return home with bluntly cut-off trunks, selected for their flared bases and roots rather than for their tapers. We know that we must still construct trees on these bases, but like building a house, the foundation is the most important consideration. There are any number of techniques to create taper in these stubbed off specimens but most are similar, in the sense that they all require at least some further reduction in height to allow space for at least two subsequent cut and grow cycles. This is necessary to achieve a believable taper and still fall within the guidelines of the top height a bonsai should be.

These techniques are also similar in that they are usually geared to producing a tree with an undisputed apex. In other words, they are used for training cypress into the immature form. However, those of us interested in finding collected material suitable for constructing flattop-style bonsai (the mature form for the species) find it impossible to work with these chopped off specimens.

Usually when designing a flattop-style cypress one must work with trees that have a much smaller caliper trunk to arrive at any believable outcome. My idea was to use large-caliper collected bases with their stovepipe-like trunks and to use them in a novel way that would effect a more natural taper. I don't even have an official name for this trunk caliper reduction technique yet but it struck me that it would be the perfect device for creating a flat topped cypress bonsai with a thicker base.

I discussed my idea with one of my most talented students Alex Leong, who was in our Thursday night study group.

Alex had coincidentally just been given a collected cypress with a large, stubbed off base by a fellow club member. He brought it to our Thursday night study group.

Although I could explain what I wanted to try to do, I wasn't able to create a drawing with perspective enough to show what the tree would look like after its trunk had been reduced using my new technique. Alex grasped the concept immediately and was able to produce a drawing on the spot. With Alex's sketch my concept could be understood immediately by anyone who saw it. Even with my diminished cognizance due to brain tumors, I could sketch my concept now.

The technique provides taper by creating three separate shelves that spiral around the trunk with the remaining portion providing an apex. The trunk's lateral cambium, just below these shelves, then gives rise to three major branches. We might refer to these as a first branch, a second branch and a back branch. The accompanying photographs will show you how it is done better than my muddy description ever could. And so we began.

First, we marked the end of the stump, dividing it into quadrants. Each quadrant would be cut at a different level on the trunk, forming separate "shelves."

Our goal was to reduce the caliper of our "the stovepipe" incrementally up the trunk, starting from where we wanted the first branch to be. The quadrant marked "1" would be the lowest shelf and include the first branch; the one marked "B" would be the next highest shelf and include the back branch; the one marked "2" would be the third highest shelf and also has an arrow showing the intended front of the tree; and the one marked "A" would become the apex, Thus, each quadrant would assume a separate role in the tree's composition. All growth from each quadrant would be used to form a flattened crown.

Before we began to saw and chisel, I drew in the horizontal lines that would indicate the position and height of the separate shelves.

The shoulder of each shelf would be the location of a new branch fed by the trunk's lateral cambium. The levels now indicated, we took some of the branches that were lying on the floor and held them in the appropriate positions to see if the branch placement would work out the way we had planned.

The branches would be trained only as subordinate structures underneath the primary branches that formed the flattened crown. With this in mind, the placement of the branches would have to be truncated towards the top of the tree, unlike the traditional positioning of the branches on a formal upright. In fact, in this upside-down style (first proposed by me several years ago) the first branch actually appears above the second and third.

Next, Alex used a skillsaw to cut on the marked vertical lines and, then, on the horizontal ones. What other way could you attack it with normal tools?

Being a cabinetmaker by trade, Alex had the right chisels and expertise with power tools to make sure that we got through the evening with no missing digits. In these photographs, he cuts down to the top of the front (number "2") quadrant.

As you can see from the pictures, what we came out with was at least a framework of the idea. Whether or not it would work was still to be seen.

We again put our branches into place, this time right on the shelves that we had designed for them. We didn't really have enough hands to do it, but we had fun trying to picture how the tree would look anyway. The other two study group members in the photo below are Dylan Grantz and Johnny Martinez.

Then we covered all the exposed surfaces with sealer. The only thing left to do now was to let nature take its course.

Unfortunately, that session marked the departure of Alex from our group to a new home in the Houston area. It was his tree, after all, and we would now have to be content with reports via telephone conversations and scanned pictures via e-mail to learn from Alex how the experiment was turning out.

As you can see in the photographs Alex e-mailed me, everything sprouted where it was supposed to have sprouted except in one instance where a branch sprouted somewhere else contributing to decay of the non-branching shelf.

From here on out I can take no credit for the tree's training and development except to note that Alex brings honor to his teacher and fellow study group members by keeping the tree alive and continuing to direct its growth in a manner consistent with its chosen style. Alex's sketches of other possible directions for the tree are very intuitive and represent excellent work.

As we had originally planned, Alex intends to unify the composition. The tree's growth and decay will clarify what should remain the healthy solid part of its structure. If you look at the pictures of Alex at work in training and carving his tree, I think you will agree that it is progressing very nicely towards that end.

There remains only one question to be answered, "Did the trunk caliper reduction technique prove to be a valid option for creating flat-topped cypress bonsai from poorly tapered collected material?"