The fertilizer in our bonsai is a fundamental issue for the health of our macrobonsai. It’s kind of an afterthought. We all know it is necessary, but we don’t understand exactly how it works or how it can be manipulated to help us achieve our goals. People tend to think of fertilization as unique, neatly packaged knowledge that they can learn and apply uniformly to their trees. Unfortunately, as with most things in bonsai, it is more complicated than that.
The main tenant of fertilization that you need to keep asking yourself is: what am I trying to accomplish? Your design goals, tree health, stage of development, season, etc. –The correct application of fertilizer is nuanced, depending on what you are trying to achieve with your tree.
The most important thing to understand is that the subscriber is supplemental nutrition, not food. Trees survive on stored energy captured through photosynthesis. Therefore, trees do not technically need fertilizer to survive, but without it, the tree may be thought to be undernourished. When applied correctly, the fertilizer increases the efficiency of the metabolic processes that supply nutrition and energy to the production of new shoots.
The how, the when and the why
Fertilization allows us to build foliar and root mass, lengthen and thicken branches, heal large wounds and facilitate back formation. It is the growth accelerator that we step on hard or press lightly to guide the tree in the directions we seek. Subscribing should always be combined with a foliar management technique, a way to use and control the energy of the tree.
There are two facets to subscriber control: frequency and quantity per location. The number of locations on the ground surface is directly proportional to the size of the container; this does not change. A 30cm container is the approximate standard, between 8 or 10 locations evenly distributed throughout the floor and up to the edge of the container. When adding more fertilizer, do not remove the previous application as it is still breaking down, incorporating nutrients into the soil. New fertilizer applications must be evenly spaced between older applications.
Fertilize your bonsai in spring
In the spring, the fertilizer perpetuates foliar growth, setting our trees for multiple downloads or good feedback.
Playing with this accelerated accelerator pedal depends on what you are trying to achieve. If you are trying to set structural goals, such as thicker and longer branches, greater foliage mass, establish roots, heal wounds, or cause sticking.
If you are trying to build secondary branches, create lignified tissue, or create a scaffold that will be wired, you should fertilize moderately.
If you are trying to refine a tree, which means reducing the length of the internode, building fine twigs, distributing force, lightly fertilizing, and considering application timing as an important tool.
The Macrobonsai technique will never be a one-size-fits-all recipe. Different trees such as: ancient, ornamental, decorative or centenary olive trees need different care. Returning to that fundamental question, what are you trying to achieve with your bonsai, will force you to think about the “why” behind your actions and techniques so that you can expand your own knowledge of the science behind the art.