Page 43 - Tài liệu Ebook cây cảnh Bonsai Basics

OBTAINING YOUR BONSAI 45

Air layering roots. Roots grown by this method are
This is a completely artificial way of particularly delicate and although they
propagating, which offers a number of will be tightly wrapped around the new
advantages for bonsai creation. Well- tree, you should not attempt to unravel
formed plants can be obtained quickly them. Once the tree is planted they will
but, most important, the girth of its unravel themselves naturally. Separa-
trunk is that of a much older established tion and planting should only be carried
tree. The technique is relatively simple, out during dormancy. Air layering is
though the results cannot be guaranteed. also useful for shortening the trunk of a
Be warned that a branch prepared for air bonsai which has grown too tall.
layering is irretrievably damaged, if the This method of propagation is par-
operation is not a success. ticularly suitable for indoor plants and
As with simple layering, this method for those raised in a greenhouse, since it
will allow you to choose which part of is easier to keep the moss in which the
the branch you use. Its shape should suit roots grow damp in the controlled envi-
the style of bonsai you wish to grow. ronment of a greenhouse.
Unlike simple layering, air layering al-
lows you to use part of a branch from
any level of the plant.
You will need a very sharp grafting
knife, a polythene sheet, a piece of string
or raffia or two elastic bands, and some
moss cut from the base of a tree, perhaps.
Select the part of the branch that will
form the base of the bonsai, make two
cuts right round the branch, 2-3 em (i
1! in) apart, taking care not to damage
the wood. Carefully remove the bark
between the two incisions and sprinkle
some hormone rooting powder on the
exposed part with tweezers. Then cover
with damp moss and form a sleeve from
the polythene to keep the moss in place. In air layering, a ring is cut in the branch chosen.
Tie to keep the sleeve tightly sealed at
both ends. Roots will grow into the
moss. This takes about one to two
months for deciduous trees but three to
six months for conifers, which are more
difficult to produce by air layering. The
incision can be ringed with copper wire
which is inserted in the cut to slow down
sap circulation, causing the tree to grow
new roots in an effort to survive. Air
layering is usually most successful in
spring, at a time of most active growth,
when the leaves first appear. Obviously,
the layer should not be severed from its
parent until its roots are well developed.
The roots will usually grow through the
polythcnc sheet on their own. The
The incision is treated with hormone rooting
branch can then be cut below the inci- powder and wrapped in damp moss. It is then
sion, taking care not to damage the enclosed in polythene.