Page 11 - Tài liệu Ebook cây cảnh Bonsai Basics

HOW TREES GROW 13

CONDITIONS FOR

DEVELOPMENT

Soil certain intensity of light will thrive. ln
While the physical properties of the soil bonsai cultivation, a choice must be
provide a secure anchorage for a tree, it made: whether to opt for one species
is the soil's chemical composition (itself rather than another to suit the location
linked to the physical structure) which (for example, balcony or patio) or to
enables the tree to develop and grow. select the exposure to suit the needs of
First and foremost, the roots draw the plant as in larger areas such as
water from the ground, vital to the gardens, large terraces or balconies with
process of photosynthesis already de- different aspects.
scribed. This water also contains essen- Before you buy a bonsai tree, you
tial mineral salts in dissolved form. must always find out the degree of
These are sure to include nitrates, phos- exposure to light it requires.
phates, potassium, calcium, magnesium
and sulphur, as well as a number of
metallic elements (or trace elements) like Exposure to wind
copper, zinc, boron, iron, manganese, This is important to the development
molybdenum, etc. These mineral salts of a tree in its natural surroundings, but
are transported to all parts of the plant less likely to affect artificially cultivated
by the sap. plants, particularly bonsai, which grow
The mineral salt requirement varies only in a strictly controlled indoor envi-
from plant to plant; this means that the ronment not subject to windy condi-
nature of the soil governs the natural tions. At the same time, one should not
vegetation of a particular region. Where overlook the fact that wind may accentu-
trees are grown in containers (bonsai ate the ambient conditions. For
trays or trees in tubs), the potting com- example, a bonsai exposed to the sun will
post chosen should be adapted to the be more prone to dehydration if it is
needs of the tree. exposed to wind at the same time. By the
same token wind increases the risk of
frost in cold conditions.
Exposure to light Generally speaking, a bonsai should
As we have already seen, light is indis- not be grown in a windy place, such as
pensable to the process of photosynthe- the edge of a balcony or terrace.
sis, without which the plant cannot Draughts should also be avoided, as
develop. Exposure to light is often con- these prejudice normal plant develop-
fused with exposure to sunlight, which is ment. Of course, where bonsai are grown
not the same thing at all. Some plants outside, their containers must be firmly
which require a great deal of light may anchored, so that they cannot be
suffer from prolonged exposure to the dislodged by a gust of wind.
sun, whose hot rays may cause rapid Where bonsai are put on window or
dehydration of the plant. balcony ledges, the trays must be secured
All trees need light, but the amount with steel wire. In some cases, the plants
and length of time may vary. In nature, a may have to be anchored or braced,
tree may 'choose' its exposure to light, to which will also prevent them being
the extent that only plants exposed to a forced out of shape by prevailing winds.