The 50% Rule

By Chris Pogliano

Visiting masters are a wonderful way to further your understanding of bonsai. Every time we have one visit, we seem to be left with a golden nugget of wisdom which becomes the topic of discussion for the society at large. We were recently lucky enough to have Dennis Makashima as our visiting master. During his workshop he gave one of those very golden nuggets. THE 50% RULE!
The 50% rule states, “DON’T remove more then 50% of the tree’s foliage or it will be greatly stunted and may even die!”

Dennis Makashima and Cheryl Sykora – Image by: Randy Davis

I thought this was a very enlightened comment considering the way we attack a tree in this hobby, seeing masters do demos where they chop at the tree as if nothing could kill it. I felt a need to explore this further. Here is what I found through my studies and discussion with more senior members of the MN Bonsai Society.

1. Don’t remove more then 50% of the foliage.

This is taught in many landscaping courses as well. It is based on the principle that a tree is a complete system that requires roots to support healthy leaves as much as leaves are required to support healthy roots. If there is too much of a reduction in number of leaves in a tree t he roots will grow weak. The new growth to replace the leaves will be stunted and not as efficient at supporting rapid tree growth. This stunts the tree. (This principle is exploited in defoliating and candle cutting. It is also why you only want to candle cut and defoliate trees that are very healthy and in the refinement oriented stages of development. It results in smaller leaves and shorter internodes.)

This can be further developed into principle 2.

2. Don’t remove more then 50% of ANYTHING!

Removing more then 50% of the roots is just as detrimental. This is why in repotting years the tree often exhibits stunted growth, requiring less trimming and a decreased need to do candle cutting and defoliating. Don’t get me wrong, if it is very vigorous you may need/want to do it but it still will be weaker than in other years. Root bound is another factor but a topic for future articles.

All of this caused me to stop and wonder. There are so many situations that require us to remove more then 50% of either the roots or the shoots. How can the 50% rule be used to increase tree survival in these situations?

3. If you MUST remove more then 50% of either the roots or the shoots, you must balance the remaining part of the tree; to bring it back in line with the 50% rule.

Say, for example, you are collecting a tree and need to remove 70% of the roots to get it out of the ground. First of all, I personally don’t feel you should collect the tree unless you have to and you know what you are doing. Second, cut back some of the foliage so the tree is within the 50% difference range. We have many skilled collectors in the club, please look into doing a weekend apprenticeship with one so you can learn the craft. We have a really strong pool of knowledge in this club: it would be a shame to not tap into it!

Dennis Makashima at Master’s Workshop – Image by: Randy Davis

All of this leads to the golden rule of bonsai; one I have heard masters say time and again.

!!!!!!!!!Know Your Trees!!!!!!!!!

As a general rule, a variety of tree that roots easily and back buds easily will be able to handle a greater assault to either their roots or their shoots. This is why you see people chop at the roots and branches of ficus and maples really hard and have the tree live while a pine may die if treated in the same fashion. Know your trees.


The best way to learn your trees is experimentation, connecting with your fellow club members and study with the visiting masters.— Please take advantage of these wonderful opportunities.