Horticulture is far more complicated than turf care.
Horticulture is the science, art, technology and business involved in intensive plant cultivation for human use. It is practiced from the individual level in a garden up to the activities of a multinational corporation. It is very diverse in its activities, incorporating plants for food (fruits, vegetables, mushrooms, culinary herbs) and non-food crops (flowers, trees and shrubs, turf-grass, hops, grapes, medicinal herbs). It also includes related services in plant conservation, landscape restoration, landscape and garden design/construction/maintenance, horticultural therapy, and much more. This wide range of food, medicinal, environmental, and social products and services are all fundamental to developing and maintaining human health and well-being.  http://en.wikipedia.org/wiki/Horticulture
Let's not even get into this discussion here with only a few sentences per post.