Incident to the growing of the plants are all the questions of plant-breeding, variation of plants under domestication, and the bearings and applications of many biological and physical sciences. From this quote, it can be seen that horticulture has changed little in meaning since 1904. Technology has transformed horticulture into a very real science. Its objectives are to increase the numbers of a plant and to preserve its essential characteristics. Propagation may be achieved sexually by using seeds or asexually by utilizing techniques such as cutting, layering, grafting and tissue culture.
Seeds are the most commonly used means of growing new plants.
Seeds are inexpensive, easy to transport and store, may be kept for long periods, and produce plants that are disease-free. Their disadvantages are the long time required for new plants to develop, and the possibility of the heterozygous seed possessing unwanted, recessive characteristics not apparent in the parent plants. The latter may be controlled by selective breeding programs. It ensures that a superior plant may be reproduced endlessly without variation, and is faster and easier than growth from seed. Layerage and cuttage are horticultural practices that induce plants to propagate by removing a shoot or adventitious root.