Propagation is the art of using known plant tissue to regenerate a plant. Some plants don't produce viable seeds, some produce seeds that are difficult to germinate, and some have a mix of parentage that is not usable. Plants that fit these categories are propagated by several methods air layering, budding, grafting, or rooting by using cuttings collectively called asexual propagation. Many hobby gardeners and professional horticulturists use these methods when plants are difficult to propagate any other way. Each plant subsequently produced is genetically identical to the mother plant. Shrubs, houseplants, some trees, and most ground covers are propagated asexually. For now, let's just concentrate on cuttings.
Terminology
Cuttings - cut pieces of healthy, growing stem 4 to 6 inches long, to be used in this propagation process
Hardwood cuttings - pieces of stem taken in early spring before the new growth begins
Softwood cuttings - pieces of stem taken after the new growth begins
Semihardwood cuttings - pieces of stem taken in late spring or early summer (the most common type of cutting taken)
Rooting medium - a sometimes soilless material used in containers that stem tissue is placed in to form new roots. This material must be able to hold moisture as well as drain freely. Perlite, finely ground pine bark, and vermiculite are commonly used rooting media.
Cambium - the tissue just beneath the bark that is the "lifeline" for nutrient movement within the plant. When a plant is wounded, accidentally or purposely, as when a cutting is taken, the cambium generates a healing callous from which new root growth will take place.
Rooting hormone - a powder used to enhance the rooting process; available from nursery and garden suppliers
Transplant - a cutting that has developed roots or a small plant ready for transplanting to a larger container
There are five steps to propagation by using cuttings.
Step one: Select a succulent, leaf-bearing, vigorous, 4- to 6-inch-long section of the stem from the mother plant. Cut it at the bottom of the stem at an angle. Expose the cambium on two sides of the bottom inch of the cutting by carefully slicing away the thin bark. To enhance the rooting on hardwood and semihardwood cuttings, dip this exposed cambium in a rooting hormone powder and shake off the excess (figures A through C).
Step two: Insert the cutting, treated side down, into a container of moist rooting medium (figures D and E).
Step three: Enclose the cutting tray in a plastic bag to trap the humidity. Place the cutting tray with cuttings in bright light but not full sunlight (figures F and G).
Step four: Allow plants to root in the cutting tray for three to six weeks. Test the root growth progress by gently pulling on the plant's leaves. Inspect to see if any roots are attached to the growing medium.
Step five: After the roots have been established, transplant the cutting to a small container to be grown. Gradually acclimate the transplant to the outdoor environment.
This technique will allow you to duplicate that favorite plant that you wanted to grow at your home without destroying or digging up the mother plant. Other advantages are that many plants can be started in a small space, few mother plants are needed, the propagated plants have greater uniformity than those from seedling sources, and the technique is simple, inexpensive, and rapid.
