Air layering is a simple propagation technique that was perfected in China more than 4,000 years ago to create offspring that are genetically identical to their parent plants. The process, generally used for small, woody plants, involves wounding the stem, then enclosing it in moistened moss. Roots are produced at the wound site and, once established, the new plant is severed from its parent and potted up.
An excellent method for replicating existing plant material without disturbing the parent plant, air layering has a high success rate, and good-sized specimens can be obtained in a fraction of the time it would take to grow them from seed.
In our Canadian climate, this technique is best carried out in early spring on mature wood from the previous season's growth, 15 to 30 centimetres behind the growing tip. In the case of flowering trees and shrubs, wait until flowering has finished.
Follow the illustrated steps on the next page. After four to six months, the layer should have produced enough roots to be potted up on its own (in late summer or early autumn).
Plants that can be propagated by air layering include azaleas, camellias, hollies (Ilex spp.), Japanese maples (Acer palmatum), lilacs (Syringa spp.), magnolias, rhododendrons and witch hazels (Hamamelis spp.)