Horticulture is the science and art of growing fruits, vegetables, flowers, or ornamental plants. Horticulture is different from general agriculture, agronomy, and gardening in that it involves specialization and controlled cultivation and management of plants and their ecosystems. It can be distinguished by its subfields and or unique botanical expressions. There are various divisions of horticulture because plants are grown for a variety of purposes. These divisions include, but are not limited to: propagation, arboriculture, landscaping, floriculture and turf maintenance. For each of these, there are various professions, aspects, tools used and associated challenges -- each requiring highly specialized skills and knowledge on the part of the horticulturist.