Bonsai trees are extremely delicate. It is disheartening to see Bonsai plants get ravaged by various plant diseases because of the care that a Bonsai owner has for their plants. Like Mr. Miyagi from the Karate Kid, many Bonsai owners form a relationship with their Bonsai. So many hours are spent with the Bonsai where you feed it water it, prune it, and speak softly to it. It sounds crazy, but a lot of Bonsai owners seriously form a bond of love with their Bonsai.
When a Bonsai tree gets sick from a plant disease, the owner often feels sad, and possible even depressed that they cannot help their Bonsai plant out anymore. If the Bonsai dies it can be a very traumatic experience that can be likened to having your family dog die. The emotional attachment that forms among Bonsai owners and their tiny trees make keeping the Bonsai as healthy as possible a vital activity.
There are numerous bacteria and fungi that can attack a Bonsai. All of these possible bacteria are called “stem rot”. Expert Bonsai growers may be able to distinguish between the types of bacteria and then be able to attempt to save the plant.
Most people are not educated enough to even attempt to save their miniature tree from stem rot, however you can take steps to help insure that stem rot will not occur in the first place.
You need to use a free draining soil. Make sure that you keep your soil mixture heaped up with a high percentage of inorganic soil. By keeping the soil healthy you can keep bacteria and fungi from growing in the soil and attacking the roots. If you soil contains stagnant water that cannot drain off then your Bonsai has a much higher chance of getting one of the various stem rot diseases.