Page 110 - Tài liệu cây cảnh Bonsai4me Bonsai Basics

Chapter 14 Fertilising Your Bonsai

Although Bonsai are repeatedly pruned throughout their lives to keep their
small stature; they are never deprived of nutrients to stop them growing. A tree
planted in the ground is able to extend its root system in search of nutrients

however a tree planted in a bonsai pot is unable to do so; after a short period of
time the soil in a bonsai pot loses its nutritional content as the tree consumes it,
much nutrition is also lost from the effects of watering and is literally flushed out
of the soil. For a bonsai tree to continue to grow strongly (if at all) the soil it
grows in must have its nutritional content repeatedly replenished.
Plant Nutrients
In order to grow, trees use carbon, hydrogen and oxygen from the air, and
water from the soil to manufacture their own starch and sugars. They also need

from the soil a number of simple chemicals which they then use to create amino
acids, proteins, vitamins and enzymes.
All organic soils have a stock of these vital chemicals; they come from the
mineral part of the soil (sands/clays etc) and from dead organic matter (fallen
leaves and dead plant matter). However, in the confines of a bonsai pot these
vital elements are soon lost. Inorganic soils such as Japanese clays (Akadama
etc) and Diatomite commonly used in bonsai soil mixes can be completely
lacking in one or more of these elements even before use.
The most serious loss concerns three elements; nitrogen, phosphorous and
potassium. These are known as the major plant nutrients and are required in
relatively large amounts if plants are to grow satisfactorily. There are a further
number of 'trace elements' that are required to be present in the soil but only in
small quantities.
Nitrogen(N) is primarily used by plants for leaf growth, Phosphorous in the
form of phosphates (P2O5) is primarily used by plants for root-growth,
Potassium in the form of Potash (K20) for flower and fruit production.

Fertilisers
To supply your bonsai with a continual supply of essential plant nutrients it
is necessary to regularly apply fertiliser. There is NO need to purchase 'bonsai
feed' or any other 'special' bonsai fertiliser. Essentially ordinary plants, bonsai
are more than able to cope with ordinary soluble garden fertilisers. It is far more
important that a fertiliser with the correct nutritional balance is chosen.
By law, the manufacturer of a product described as a fertiliser must declare