layering

layering horticultural practice of propagating a plant by rooting a branch before severing it from the mother plant. Typically the branch is bent and a section that has been slit or broken on the underside is covered with soil and held in place by means of stakes or pins. Trench layering induces new shoots from a length of buried branch. In mound, or stool, layering, the many shoots of a closely cropped young plant are heaped with soil. Air (or pot, or Chinese) layering is used when the branch cannot be bent to the ground; peat moss or some other suitable rooting medium is attached to a cut place on the branch. Layering is used mostly for multiplying plants not easily propagated from cuttings. Some plants propagate naturally by layering, e.g., raspberries, strawberries, and chrysanthemums.

Bibliography: See bulletins of the U.S. Dept. of Agriculture; H. T. Hartmann, Plant Propagation (1968).