Young plants can produce roots at every-leaf node along their stem, although not all plants retain the ability- to do this easily as they mature.
The formation of roots is triggered when the hormones in a cutting respond to stress. These hormones are concentrated in the growing tip, but can also be found in each leaf node. The younger the plant, the greater the chance that almost any part of the stem will root if there is a leaf node present.
Stem
Some plants root so well that a growing tip on the cutting is not necessary. From a long shoot it is possible to take the tip cutting, then cut the rest of the stem into similar lengths, making each top cut just above a leaf node, and each bottom cut just below a leaf node.
Heel
Short side-shoots of 3—4 in. (7—10 cm), taken as ti j cuttings, can be pulled from the stem complete with a “heel” of bark attached. This strip should be trimmed down to a short point with a sharp knife, to prevent it rotting.
Cane
Plants such as cordyline, dieffenbachia, dracaena, and yucca, which form strong, woody stems, can be propagated by cutting one of their bare stems into several pieces, each 2—3 in. (5—7 cm) long. The pieces are laid horizontally onto the soil or inserted vertically into it. If they are vertical, they must be placed the same way up as they were growing on the parent plant.
Tip
Remove the end of a shoot, including the growing tip and at least 3—4 in. (7—10 cm) of the stem. Trim the cut end under a leaf-joint (node), and remove the leaves from the lower third of the cutting. Dip the very end of the cutting in rooting hormone and tap off the surplus. Insert the cutting into a pot of moist soil by pushing it in to ensure that there is a good contact between the stem and the soil.
Alternative rooting methods
While some plants root easily, others need help in the form of rooting preparations designed to enhance the natural hormones that promote root formation.
Rooting hormone, available in powder or liquid form, is designed to mimic the action of the plant’s natural hormones and boost the rooting process. Not all plants need it — for example, geraniums tend to rot if it is applied.
The preparation should be kept clean to prevent it from deteriorating, so only pour a small amount into a shallow container, and discard the remainder once the cuttings have been prepared. Never c ip the cutting directly into the pot. The powder is quite powerful, and is needed only on the cut surface, so make sure you dip only the very end of the cutting into the powder and tap off any surplus.
Rooting in water
Many plants, especially those with fleshy stems, root easily in water.
They can be transferred to a soil mix as soon as the roots appear.