Worldwide canna virus has been reported and was known about roughly 20 years ago. Today we know there are 5 different types of viruses that affect cannas, Canna Yellow Mottle Virus (CaYMV), Bean yellow mosaic virus (BYMV), Canna Yellow Streek Virus (CaYSV) Cucumber mosaic virus (CMV) and TAV, Tomato Aspermy Virus.
Often plants will be carrying one or more different virus strain, the following pictures show the ugliness that is evident of the leaves and flowers.
Plain green and Bronzed Canna leaves should be perfect and clean to look at without any streaks or uneven coloring's and patchiness of them unless is a true variegated leaf canna, unfortunately I along with a close canna loving friend have come to realize a lot of people don’t realize they have virus-ed plants and sell them on ebay, facebook marketplace and Gumtree etc, all the time spreading it around and even more unfortunately some people simply don’t care, they appear just happy to cash in on sale to the unknowing buyer and so the cycle continues and gets worse.
Infected plants must be removed from your property, if you don’t get rid of any infected plants it can become rampant affecting other cannas that are growing nearby, some canna collections around the world have had devastation wiping out their entire collections.
Flowers can also show tell tale signs of virus's, often however not always there will be block of broken color on its flowers, canna flowers colors blend not break as pictured above.
A virus free cultivars flower, how it is supposed to look, note the darker red spotted blotches.
Same cultivar however different location and grower, this have been affected by a virus, note the long irregular broken streaks of color,
Another flower showing virus.
more leaves showing virus, streaks and leaf distortion and color breaks on flower.
If in doubt, Throw it out.
In recent years many growers and backyard gardeners have become aware of viruses and now a lot of reputable sellers worldwide are proudly growing and selling clean cannas, however not all sellers, some are still selling virused plants on Facebook.
this is from the same clump of plants as pictured above, this is also virused, note the yellow vein break
Virus in cannas is spread from plants to plant by aphids and other leaf sucking insects.
Trimming leaves from an infected plant a then trimming leaves of a clean plant can pass along and spread the virus.
Pull up and remove obvious infections and keep a look out for the little telltale signs.