Extract from Wikipedia. ........
Horticulture involves nine areas of study, which can be grouped into two broad sections: ornamentals and edibles:

• Arboriculture is the study of, and the selection, plant, care, and removal of, individual trees, shrubs, vines, and other perennial woody plants.
• Turf management includes all aspects of the production and maintenance of turf grass for sports, leisure use or amenity use.
• Floriculture includes the production and marketing of floral crops.
• Landscape horticulture includes the production, marketing and maintenance of landscape plants.
• Olericulture includes the production and marketing of vegetables.
• Pomology includes the production and marketing of pome fruits.
• Viticulture includes the production and marketing of grapes.
• Oenology includes all aspects of wine and winemaking.
• Postharvest physiology involves maintaining the quality of and preventing the spoilage of plants and animals.