Practically all perennials can be propagated by cuttings. The clipping itself should be made at a sharp short diagonal, just below a node or joint. The cutting should be wrapped in damp newspaper and exposed to the air for a half-hour or more. This does not apply to plants which exude a milky juice. Such cuttings should be sprinkled with water and exposed to the air for two hours.

Leaf propagation

Many perennials can be propagated by causing a leaf to root. Plants with thick fleshy leaves, like begonias and gloxinia, are particularly suited to this method of increasing their number. The leaf stem is inserted in the rooting medium and cared for as in the case of cuttings. Some plants can be propagated by placing the leaf flat on the rooting medium and weighting it down with pebbles. A slight cut is made through the main vein of the leaf.

The use of plant hormone will materially improve the chances of propagating successfully from leaves, even in the case of plants generally considered difficult to propagate by this method. Hormones are particularly successful with holly, magnolia, rhododendron, azalea, taxus and many others.

Propagation by Division

Dividing clumps is one of the simplest methods of propagation. It is, in addition, good for the old divided plants. Many perennials deteriorate if left in clumps for too long a period. Dividing them insures continuous health and growth. The plants are carefully removed from the soil, in clumps, and divided simply by pulling them apart. Care should be taken to injure the roots as little as possible. Divided plants are potted, or if the division is done early in spring, as with the hardier perennials, the new clump is planted in another section of the garden. The new planting should be well fertilized and watered.

Layering

Layering is another simple method of propagation. It is adaptable only to those plants which root easily when their stems are in contact with the ground. Broad-leaved evergreens in particular
(i.e., rhododendron) lend themselves well to this method.

Simple layering involves anchoring the supple stems of plants into the adjacent soil by bending them over and burying them. Black raspberries, for example, are easily propagated in this way. For plants with less supple stems, a notch is cut about 18 inches from the tip of the stem and propped open with a twig or sliver of wood. The branch is then bent to the ground, and the notched portion covered with soil. This type of layering is best done in spring or summer. Leaves should be removed from the stem which is being used for propagating.