To encourage ramification and crown development of your bonsai you will need to remove certain apical buds or stem tips periodically.
The reason for this is to control the apical dominance of apical buds that are present which suppress the growth of axillary buds especially towards the tops of stems.
However, both another technique can be used beyond just apical bud removal, and this works well on some species to promote back budding which is leaf removal behind the apical shoot whilst leaving the apical shoot intact as per the images below.
The reaction of pruning out the apical buds stops the production of auxin as it eliminates the source. Auxin produced at the bud tip stops the side buds from developing to aid growth upwards as opposed to outwards.
However, by removing the apical bud the side buds develop making the tree denser with buds along branches as opposed to at the ends only.
- Apical bud = bud at the tip of a stem
- Apical dominance = The inhibition of axillary bud growth by the apical bud
- Axil =The angle between the upper surface of a leaf and the stem to which it is attached
- Axillary buds are buds located in an axil at the base of a leaf
Sources of information:-
- Capon, B (1990) Botany for Gardeners An Introduction and Guide. Timber Press
- Linked from Bonsai Tonight image of Pine buds
- Linked from Study Blue.com images of branches and buds
- Linked from Greenspade.com images of types of buds