Trunk Chopping for Improving Trees

Figure 1 - Five Trident Maples

The five Tridents were dug from a tree farm. They were in five-gallon containers, but had grown right through the containers, and the roots had bolted to the earth. With the roots firmly established in the ground, the roots had quickly grown extra large outside of the can, making removing the roots from the container very difficult. The plants were dug from the ground, can and all. (Figure 1)

Upon arriving home I inspected the trees and found that the root spread within the container was good and that the large portions of new wood were on the outside of the can. If I could just remove the outside portion of root wood and those roots, I might just be able to start the root ball over with what was in the can. The idea was to chop the root ball off at the can line or shorter. The cans were removed by splitting them and the root balls were inspected. It was decided that the root mass could be reduced by half with the initial chop. I cut straight thru the entire mass with a saw and removed half the roots from each tree. During the course of this article, three trees were treated the same. Pictures shown will be on individual trees and can be assumed that the treatment for each was the same.

The Major Chops

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The trees were planted in a medium of small lava and pure sand. At this time I needed the plant to put out as many roots as possible. Sand makes this happen.

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In spring of 2005 the growth from the previous year was pruned back. All cuts on the base of the trunk were removed and a small stub was left. This small stub is the key to growing out the base of the trunk. It is through this scarring that the lower trunk gains mass. The leader was preserved and was taken to a point that I felt would make a pleasing taper. This visual point is personal and could be done much higher or lower. I estimated how much the plant would grow on the next year's grow-out, and decided to make my chop at that point. Since these were to be grown out for Shohin stock, my purpose was to keep these trees rather compact in height. During spring of that year, all growth was allowed full reign. The new leader and any suckers that popped from the trunk were allowed to grow unchecked. This helps for two reasons. First, it allows the cuts from the previous year to heal faster due to the extra water from all the growth, and two, it takes away some of the focus on the leader and keeps it in check. That year’s growth was about 8 feet tall. Once again near fall the fertilizer was cut back and changed for winter and the tree was moved to a more protected spot. With all the open places on the trunk I wanted no frost to split the trunk.

More Trunk Chopping 

Winter 2005/6

During the winter of 2005 I began a process of refinement that will start to build the character of the tree. Although the shape of each of the three trunks could be considered unique, two were rather similar and one was very different in shape.   All the leaders were pruned back short for shape and the small suckers at the bottom were now pruned close to the trunk for healing. At this point I do not need to build any more new growth for trunk size, but need to focus on branching and healing over of the carving. The carving was done during this winter to help build the trunk shape. The trunks now have gained a full inch in girth from the scarring process and are 3” across at the soil line. The large chop line from the initial chop had started to close over with scar tissue. It was necessary to carve through this scar tissue to help build taper. (figs. 13,14,15)

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Once the carving was done, all the edges were finished with a very sharp grafting knife. Slicing the live portion with a sharp knife will help promote good healing. The mashing action of a carving tool ruins the cambium tissue there and the tissue will just recede and heal at a very slow rate. What will be needed to help heal this area over will be good sacrifice branching near the top to help speed healing. This sacrifice branch will have to be chosen carefully to not ruin the great trunk line that is already there. Had the initial cut been made a more straight across in the beginning, I could have skipped this part completely.

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Since the trees had been in the pots since the initial chop, I used this year to do another root reduction. Upon inspection of the pots it was noticed that roots had completely filled the containers. Mycorrhiza had also been present amongst the roots. (fig. 8) The roots were further reduced by another 50 percent. The root mass was reduced with the aid of a saw. (fig. 9) I literally sawed thru the middle of the root mass and removed as much wood as possible from the initial plant growing thru the container. (fig. 10) During this phase of the reduction special attention was made to get a radial root spread of the roots in the container. (figs. 11,12) While most of the larger roots are gone now, some have remained and have been cut so as to promote a nice nebari within the pot in the future.

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