Originally Posted by chong

Air layering is a method of plant propagation by splitting, or nicking a portion of a stem of the plant, then wrapping the "wound" with soil or other medium, and an impermeable membrane like plastic, tin can, etc. to hold the medium. When the stem has sufficiently rooted in the medium, the stem is cut below the wound and planted in a pot or the ground after removing the outer cover/membrane.

Check out the link on this thread: Air Layering