floriculture, branch of ornamental horticulture concerned with growing and marketing flowers and ornamental plants as well as with flower arrangement. Because flowers and potted plants are largely produced in plant-growing structures in temperate climates, floriculture is largely thought of as a greenhouse industry, though many flowers are cultivated outdoors in nurseries or crop fields. Both the production of bedding plants and the production of cuttings to be grown in greenhouses or for indoor use as houseplants are usually considered part of floriculture.