Having a good bonsai soil is a vital part of keeping your bonsai healthy. For the beginner, selecting a good bonsai soil is a daunting task. For the experienced bonsai grower, a good soil makes the difference between a thriving, healthy tree and one that will only survive a few months to a year.
When you are selecting bonsai soil, there are a few things that you need to keep in mind, regardless of whether or not you are an experienced grower. Bonsai trees require quick draining soil that maintains its shape in order to stay alive. Due to the small amount of space that a bonsai has to work with, if you do not have good soil, root rot is much more likely to occur. Root rot is a death sentence for a bonsai tree, and can quickly ruin years of growth of your tree. In addition to this, poorly chosen soil has a tendency to break apart, requiring the roots be cleaned yearly.
This can be particularly damaging to pine bonsai trees, as well as junipers. If you want to use soils prone to breaking apart or decomposing, such as organic soils, you will need to make certain that the tree you use this soil type with is able to handle root bearing at least once or twice a year.
One of the most popular types of bonsai soil available on the market is inorganic soils. These are fired clays that hold their shape and absorb moisture well, which the roots can then feed off of. This is important as these soils have good drainage, which prevents root rot from occurring. As high quality fired clay tends to be absorbent, there is enough moisture to allow the roots to get what they need while the excess water drains away. This type of inorganic soil is acceptable for many varieties of bonsai trees.
Acquiring good bonsai soil can be difficult if you do not know where to look. Bonsai soil can be found in the most unusual of places, including hardware stores, auto parts stores and pet supply stores. Bonsai resellers online will typically acquire their soils from these types of places and make blends suitable for certain types of trees.
When you purchase bonsai soil, it is important that you test the soil prior to use. Good quality soils will not break down easily. You should not be able to crush it in your hand easily, or break it when doused in water and then frozen.
Bonsai soil that breaks down like this will typically not last a long time and can cause some problems with certain varieties of trees.