Defoliating to move energy down
These illustrations show a few very simple points. In both methods we are trying to strengthen the the two weak secondary branches (the first two branches). These need help as energy tends to flow past them towards the tips of the primary branch. This movement of energy towards the outer tips of branches is natural and occurs in virtually all plants.
Defoliating both the strong and intermediate sections
In the technique on the left, both the mid section and the strong outer section are defoliated. This will insure that the first two branches receive a surge of energy. At least until the defoliated sections recover and put out new leaves. You’ll also notice that because so much was defoliated, a host of new buds appear.
Defoliating only the strongest section
In the technique on the left, only the strongest outer section is defoliated. The middle strength mid section is left alone. The result is that first two branches and the mid section are both strengthened. This technique is less radical (creates less stress) and results in fewer new buds.
Which technique is best?
Which technique you choose depends upon what you are trying to accomplish and how radically (or fast) you want to redistribute energy. If think the mid section needs strengthening, then you might want to defoliate only the outer section. Next year, you may decide to defoliate the mid section (as well as the outer section).
Conversely, if you feel that the mid section is strong enough (and/or its leaves are too big) and you want to push as much energy as possible back to the weaker inner section, then you might want to consider defoliating both the mid and outer sections.
Be careful
If you are uncertain about how much your tree can take, then defoliate less, rather than more. You can always do more next year.
Always allow plenty of time to recover
If you wait to long to defoliate, you might put part, or all, of the tree at risk. Don’t defoliate if there are less than two months of summer left. Defoliated trees need plenty of time to recover so that they will be at full strength going into the winter.
The illustrations are by Kyosuke Gun. They originally appeared in Bonsai Today issue #3.
Don’t forget to feed your bonsai!