The practice of horticulture has been around for thousands of years, but how is it relevant to life in the twenty-first century? Plants still represent an important source of food, fuel, clothing, shelter, medicine, perfume, and recreation; they also add oxygen to the atmosphere and help in the removal of toxic waste from the soil. We have become dependent on commercial horticulture to su pply our produce and other plant products. What if your favorite fruits or vegetables were no longer commercially available? You would either have to cultivate the plants yourself or go without them. The act of cultivation could be as simple as the use of a hoe to weed and loosen the ground under a berry bush you found in the woods or as complicated as the design and maintenance of a year-round vegetable garden.

Horticulture is the scientific term for the act of gardening. It first came into use around the eighteenth century, though gardening itself has been practiced for many thousands of years. A gardener must prepare and maintain the soil, select plants based on the climate and purpose for the garden, protect plants from adverse weather conditions and pests, and encourage growth with water and nutrients when necessary. Other roles of the gardener may include the propagation and breeding of new plants. All of these topics will be described in greater detail throughout this book.

Forestry, agronomy, and horticulture make up three branches of agricultural science. Forestry is a discipline that concentrates on trees that grow in a forest. Agronomy focuses on cereal crops, such as oats, barley, and wheat plus the forage crops that feed domesticated animals in pastures. The word horticulture derives from the Latin word hortus, which was used in Roman times to define a garden on an estate—usually one smaller than five acres. Anything larger than this was referred to as a farm.

Horticulture can be divided into four areas of specialty, two of which are dedicated to the production of food. The branch of horticulture that specializes in the growth of vegetable crops is called olericulture, whereas pomology is devoted to the art of fruit cultivation. Vegetables and small fruits such as strawberries are grown in gardens but may also be grown in large commercial fields. Fruits found on trees, such as apples, pears, and peaches, are cultivated in orchards, whereas citrus and olive trees are grown in groves. Grapes are produced in vineyards in a process called viticulture (Figure 1.1).

Cultivation of ornamental houseplants and flowering plants is the third branch of horticulture and is called floriculture when conducted on a commercial scale. The fourth branch, landscape horticulture, focuses on woody ornamentals (shrubs and trees), which are cultivated in nurseries for distribution to the public, as well as turf grasses used for lawns. Plants grown in orchards, vineyards, groves, gardens, greenhouses, and nurseries all belong in the realm of horticulture.