Sometimes
bonsai or potentsai can have poor quality nebari/surface roots
or poor quality lower trunks. This can take the form of too
few overly-thick roots, a combination of thick and thin roots
or one-sided nebari which can spoil an otherwise excellent
bonsai. This problem can be relatively easily and quickly
rectified by using layering techniques as described in the
Advance Techniques articles on Layering. Layering produces
numerous roots that emanate radially from all around the trunk
which is ideal for quality nebari.
When using this technique, repot the bonsai
into a deeper pot or the ground and leave it unpruned to encourage
vigorous growth. New roots can be developed higher up the
trunk by either air-layering or if only just a little higher
than the existing nebari, the ring-bark or tourniquet air-layering
method can be used and the tree planted deeper into the ground
or pot so the layering is below the level of the soil.
When the
new rootsystem has become well established after one or two
seasons, the old rootsystem and trunk base can be removed.
A by-product of the tourniquet method is that the base of
the trunk above the tourniquet swells resulting in excellent
trunk flare. An alternative to using wire as a tourniquet
is to plant the tree in the ground through a hole in a ceramic
tile.(For more details on this technique, please see Part
Two of this article) As the trunk slowly thickens, the
hole in the tile bites into the bark and cambium layers (as
a wire tourniquet does) and as the trunk swells above the
surface of the tile, new roots are produced. Eventually, all
roots below the tile can be removed and the tree is left with
excellent root and trunk flare, and radially spreading roots
which are flat-bottomed making them ideal for bonsai cultivation.
This technique is carried out in early Spring
at repotting time if any root disturbance is necessary in
order to apply the toruniquet. However it can be carried out
at any time of the year, if the tourniquet can be applied
and the soil level increased without disturbance of the rootsystem.
These Larix kaempferi/ Japanese Larch were
purchased as bare-root stock and typically each had a very
poor nebari with thick downward growing roots only.
