Layering is a method of propagation in which the actively growing cambium of branches or trunk is interupted by girdling or mechanical means ( wire tourniquet ) while the portion to be layered is left attached to the tree until roots form at the site of the layer. The process of layering was probably developed in conjunction with hedging. Hedges of boxwood, privet or thorns were a convenient way to designate property boundaries, particularly in the absence of good material for fences.

REASONS FOR LAYERING

Layering is performed to propagate material, to take advantage of interesting or pleasing forms, or to improve the root system of a tree. Layering is an easy way to create "perfect rootage" on a tree with a one-sided or unattractive root system.

Hello,
Layering is a means of plant propagation in which a portion of an aerial stem grow roots while still attached to the parent plant and then detaches as an independent plant. Layering has evolved as a common means of vegetative propagation of numerous species in natural environments. Layering is also utilised by horticulturists to propagate desirable plants.
Layering is the process of removing a large branch or section of the trunk of a tree to create another tree. Before the branch is removed it is girdled, protected with peat moss or other media and the girdled section is allowed to root. After rooting the branch is removed from the tree. This is a very common practice in bonsai.
This method, believed to have been developed centuries ago by the Chinese, has been used successfully as a mean of propagating some of the more difficult-to-root plants. Because it required excessive care and patience, air layering was used only by the highly trained plantsman.
Success was dependent upon the ability of the propagator to keep the rooting medium moist until the roots were formed and large enough to support the new plant.
Only since the development of polyethylene film has air layering become a practical method of propagation for the home gardener and amateur horticulturist.

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