Horticulture (from Latin: horti + culture) 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.

Typically, horticulture is characterized as the ornamental, small-scale and non-industrial cultivation of plants; horticulture is distinct from gardening by its emphasis on scientific methods, plant breeding, and technical cultivation practices, while gardening, even at a professional level, tends to focus more on the aesthetic care and maintenance of plants in gardens or landscapes. However, some aspects of horticulture are industrialized or commercial such as greenhouse production or CEA.

Horticulture began with the domestication of plants c. 10,000 – c. 20,000 years ago.^{[better source needed]} At first, only plants for sustenance were grown and maintained, but as humanity became increasingly sedentary, plants were grown for their ornamental value.^{[citation needed]} Horticulture emerged as a distinct field from agriculture when humans sought to cultivate plants for pleasure on a smaller scale rather than exclusively for sustenance.^{[citation needed]}

Emerging technologies are moving the industry forward, especially in the alteration of plants to be more resistant to parasites, disease and drought. Modifying technologies such as CRISPR are also improving the nutrition, taste and yield of crops.

Many horticultural organizations and societies around the world have been formed by horticulturists and those within the industry. These include the Royal Horticultural Society, the International Society for Horticultural Science, and the American Society of Horticultural Science.