How to Make a Bonsai Plant: Air Layering
This is a completely artificial way of propagating, which oilers a number of advantages for bonsai creation. Well-formed plants can be obtained quickly but. Most important, the girth of its trunk is that of a much older established tree. The technique is relatively simple, though the results cannot be guaranteed. Be warned that a branch prepared for airis irretrievably damaged, if the operation is not a success.
As with simple layering, this method will allow you to choose which part of the branch you use. Its shape should suit the style of bonsai you wish to grow. Unlike simple layering, allows 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 cm (3/4 – 1-1/4 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. 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 polythene sheet on their own. The branch can then be cut below the incision, taking care not to damage the roots. Roots grown by this method are particularly delicate and although they will be tightly wrapped around the new tree, you should not attempt to unravel them. Once the tree is planted they will unravel themselves naturally. Separation and planting should only be carried out during dormancy. Air layering is also useful for shortening the trunk of a bonsai which has grown too tall.
This method of propagation is particularly suitable for indoor plants and for those raised in a greenhouse, since it is easier to keep the moss in which the roots grow damp in the controlled environment of a greenhouse.