Page 59 - Tài liệu cây cảnh Bonsai4me Bonsai Basics

Chapter 9 An Introduction to Bonsai

Soils

One of the most widely debated subjects for most bonsai enthusiasts is soil
composition. Ready-mixed soils can be bought from bonsai nurseries and garden
centres but these tend to be relatively expensive. Faced with repotting more than
3 or 4 trees in the Spring, most enthusiasts learn to mix their own soils. There are
a large number of soil ingredients that can be used when mixing your own soil;
different mixes are used by different enthusiasts with varying degrees of success.
For the beginner, choosing which soil mix to use can be a daunting choice. This
article is written as an introduction to Bonsai soils, it does not discuss every soil

ingredient or mix that is available or possible, nor does it tell which soil mix is
the 'best'. The individual enthusiast can only answer that question after
experimenting over time with his own trees and care routines.
The Basic Requirements Of Bonsai Soils
A bonsai is confined to a relatively small quantity of soil throughout the year
on which its very existence depends. Through the soil in the pot, the tree must be
able to obtain water, nutrients and gases in order to grow. For this reason, a

bonsai must be planted in a good quality bonsai soil. The quality of the soil that
is used, directly affects the health and vigour of the tree. It is my experience that
unhealthy trees that lack vigour are very often also planted in a poor (often
organic) bonsai soil.
There are a number of qualities that are required in a good soil mix;
Good water-retention. The soil needs to be able to hold and retain sufficient
quantities of water to supply moisture to the bonsai between each watering.
Good drainage. Excess water must be able to drain immediately from the pot.
Soils lacking good drainage are too water retentive, lack aeration and are liable
to a build up of salts.
Good aeration. The particles used in a bonsai mix should be of sufficient size
to allow tiny gaps or air pockets between each particle. It is important to the
health of the roots that they have access to oxygen.
A particle-based, well-structured inorganic soil allows fast drainage of water
and allows fresh air to continually enter the soil. A compacted organic soil that
lacks any structure, also lacks aeration and drainage and this can lead to ill-