What is the practice that involves the art and science of growing fruits, vegetables, and ornamental plants?

The practice that involves the art and science of growing fruits, vegetables, and ornamental plants is known as horticulture. This field encompasses a wide range of activities related to the cultivation and management of plants, focusing not just on the agricultural production but also on the aesthetic and functional aspects of plants in human environments. Horticulture combines principles of plant science, landscape design, and gardening techniques to enhance the beauty and utility of spaces.

In contrast, agriculture primarily emphasizes the broader farming of crops and livestock for food production, while botany is the scientific study of plants themselves, including their physiology, genetics, and taxonomy. Silviculture deals specifically with the management of forested areas and timber production. Therefore, horticulture is distinctly focused on the specialized cultivation of various plants, making it the correct answer to the question.