Fungal Diseases Fungal rose diseases are experienced by most rosarians and can occur in most any garden. Apart from the rare instance, all fungal diseases are culturally induced. That is, the fungal spores find a home in the garden by locating environmental conditions favorable to their reproduction and infestation. Mildew Rust Canker Botrytis Anthracnose Bacterial Diseases Infection can occur in most any garden. The pathogen enters through wounds to the plant caused by improper and unsanitary pruning, grafting, mechanical injury during cultivation, or failure to prune away broken stems and roots during transplanting.
Bacteria can survive in the soil for at least two years.
Besides spreading via infected pruning equipment, insects and water are also known vectors. Viral Diseases Viruses are smaller than bacteria. As such, they rely on living organisms for dispersal in the garden. There are currently no chemical solutions for curing roses infected with a virus. The best control is to remove the rose, replace the surrounding soil, and inform the nursery or mailorder firm where you obtained the plant.