more... > Disease Image Gallery > Ornamentals > Diseases of Ferns [Image: Virus-affected Japanese holly fern] A new virus was recently described from nursery and landscape plantings of both Japanese holly and leatherleaf ferns. Diseases of Oaks [Image: Powdery mildew symptoms on upper surface of oak leaves.] Oaks, a dominant member of the landscape, are subject to a number of diseases. Diseases of Trees and Shrubs Trees and shrubs are important components of the landscape, providing structure, texture and color. A variety of plant health problems caused by biotic and abiotic agents greatly affect the quality of these plants. The use of best management practices is essential for the establishment and care of landscape trees and shrubs and the prevention of disease. Diseases of Ornamental Plants - Annuals The use of annuals in the landscape provides color and allows for seasonal changes in the landscape. Because their growth is more intensely managed than trees and shrubs, conditions are often quite suitable for the development and spread of diseases and other pests.  more articles... Diseases of Perennials [Image: Image courtesy of Kenneth M. Gale.] Because of generally low maintenance and reduced problems associated with this group of plants, use of perennials in the landscape has increased over the years. By following best management practices many of disease problems could be eliminated. Diseases of Annuals 1 [Image: Image courtesy of Dr. Gordon Holcomb, Louisiana State University.] There are many fungal, bacterial, viral and abiotic diseases associated with ornamental plants. New diseases and disorders are being discovered all of the time. Therefore, proper identification and management are needed to prevent further damage and avoid future outbreaks.