Apical growth
One of the key elements to understanding the pruning of bonsai is 'Apical dominance'. Almost all trees and shrubs, and therefore bonsai, are apically dominant.
APICAL Growth produced by a plant which is most vigorous, in the majority of species this at the furthest points of the plant from the rootsystem (upper and outermost branches).
Apical dominance
[edit] References
^ Winterborne J, 2005. Hydroponics - Indoor Horticulture [1]
^ Münch, E (1930). "Die Stoffbewegunen in der Pflanze". Verlag von Gustav Fischer, Jena: 234.
^ Turgeon, R (1991).
Pines are apically dominant, so you will need to restrain the upper branches by eliminating the strong buds and keeping the weaker ones. Since a lot of energy is directed to the apex, it is common for the upper shoots to have 5 or more buds each.
Usually the apical buds alone are stimulated into growing, whereas the
growth of all lateral buds below them is suppressed. This is called apical
dominance. Shoots do not grow in lateral direction but grow outwards.
The rounded apical meristems of the new leaders can be removed at any time during the growing season to promote interior budding and to induce new growth of the existing frond tips.
Bonsai Glossary: apical bud - A bud at the tip of a shoot.
Bonsai Glossary: bleeding - The loss of sap caused by wounding or pruning.
Bonsai Glossary: callous - Woody 'scar' tissue that grows over a wound.
Secondary branch development is encouraged by periodically removing the apical bud (Meristem) from the primary branch. Tertiary branching are encouraged by removing the apical bud (Meristem) from. the secondary branches.
This type of growth is referred to as apical growth and is stimulated by the growth hormone auxin. Apical refers to the top or apex of the tree and the ends of branches. Another group of growth regulators, cytokinins, do the opposite.
Trees have a natural tendency to distribute most growth to the top and outer edges, which is called 'apical dominance'. This natural mechanism encourages trees to grow higher in order to prevent the tree from being shaded out by competing trees.
Strong apical growth of upper part of tree, so it may be necessary to cut back radically at the apex, but to prune the lower portions of the tree conservatively, especially with the Japanese species, to check its rapid apical growth.
The key to the whole process is that pines are apically dominant and always want to grow up from the furthest tips of the tree. Everything you do is to try and combat this tendency and redistribute vigor.
Bear in mind that due to the apical dominance of pines, the strongest growth will be on the top and outside of the tree. Therefore, the techniques for improving pine ramification e.g.
Without pruning, their natural apically dominant growth habit will take over; the upper and outer branches and shoots will extend strongly at the expense of the inner and lower growth, that could eventually dieback.
Pines, such as the Black Japanese Pine, tend to be very apically dominant. This means that the great majority of the energy used by the tree goes into growing the upper branches of the tree.
If you top prune a tree while it is dormant, you remove outlets, that is buds, for receiving food in spring, the result is the over stimulation of the existing buds, that are released from apical dominance (no more 'stop' hormones from the now cut ...
5 cm, abaxially sparsely pubescent, densely so along veins, glabrescent, with conspicuous veins, adaxially glabrous, base cuneate or attenuate, margin irregularly doubly serrate or serrate, 3-lobed, rarely 5-lobed in apical part or not lobed, ...
 See also: Tree, Bonsai, Growing, Trunk, Species
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