The genus Canna is susceptible to certain plant viruses, which may result in spotted or streaked leaves, in a mild form, but can finally result in stunted growth and twisted and distorted blooms and foliage. Known species of virus are:
- Canna yellow mottle badnavirus (CYMV) infecting canna species.
- Bean yellow mosaic virus (BYMV) infecting cannas, gladiolus, freesia and many legumes.
- Tomato aspermy virus (TAV), causes mosaic in cannas, but it has not been reported affecting cannas in the UK.
- Cucumber mosaic virus (CMV), cannas are susceptible to this virus, but none found yet in England.
- Canna yellow streak virus (CaYSV), recently discovered by scientists at the Central Science Laboratory in England. Dr Rick Mumford, senior virologist at CSL is quoted as stating "Typical virus symptoms include flecking, mosaic, leaf streaking and necrosis, which in severe cases render plants unsaleable." The reference to this quoted article is shown below.