AboutJohn Cawly Expertise I can help with identification and possible treatment of plant diseases that affect houseplants and horticultural species, to include both biological (fungal, bacterial, viral, parasitic etc.) and environmental/cultural (watering, potting media, etc.) aspects.
Experience Practical experience with a wide variety of houseplants and greenhouse plants, including cacti, euphorbia, african violets, amaryllus, and many others.
Organizations American Phytopathology Society
American Society of Plant Biologists
American Society for Virology
Publications Molecular Plant Microbe Interactions
Proceedings of the National Academy of Science (in print)
Rhodora -- Journal of the New England Botanical Society
Allelopathy Journal
Education/Credentials BS, Southern Illinois University - Biological Sciences MS, Southern Illinois University -- Biological Sciences - Genetic Engineering Specialization PhD, University of Missouri Columbia -- Plant Microbiology and Pathology (Viral Diseases specialization/Biotechnology Emphasis)
Question My outdoor pansies have black spots on their leaves and some of them are dying. My aloe vera was outside and now it has black spots too and looks poorly.
Answer Hi Gennie,
Have you had an unusually wet spring? These conditions provide ideal conditions for fungal spore germinations. The aloe plants also can have ring spots or black spots that are related to both bacterial and fungal diseases.
I am afraid that without more information, I cannot answer your questions well. I can examine photos if you have them. They can be sent to me at:
