Ornamental plants, often simply referred to as ornamentals, are usually grown in the flower garden or as house plants. They may also be used for landscaping and for cut flowers. They improve the aesthetic value of the home and the landscape and are a source of enjoyment for gardeners and visitors. Ornamentals usually are raised in the nursery or greenhouse before they are planted in the landscape or sold as cut flowers or as house plants.
Diseases can significantly reduce the aesthetic value of ornamentals. Environmental conditions in the landscape, nursery, or greenhouse often are favorable to development of ornamental diseases. Because of the high relative humidity, the greenhouse environment can especially be favorable to certain diseases that affect flowers, leaves, and stems of ornamentals. Improper or excessive watering can lead to development of crown and root diseases.