Ask the Expert: Canna Virus
Streaky foliage in Canna is often an indication of Canna virus.
Question: I've been overwintering my Canna lily tubers for several years now by storing them in a dark coat closet. In my garden last year, the leaves look all streaky and diseased. Did I do something wrong?
- Beth A. from Troy
Answer: Sounds like you are observing the symptoms of one or more pathogens in the Canna virus group. The Canna genus is susceptible to several different viruses that can cause a variety of symptoms including mottled or streaky foliage, as well as distorted or stunted growth of both foliage and flowers. It can be difficult to identify the virus on some of the showier, variegated foliage types. Some of the viruses are spread from plant to plant by aphids, while others are thought to be spread mechanically by contaminated garden tools or from the division of infected tubers. Since the damage is caused by a virus, there are no pesticides that can treat the infection (much like how a human virus cannot be treated with an antibiotic). Infected plants should be
disposed of, preferably in the garbage rather than in your compost pile. I have experienced Canna virus in my own garden and it is really disappointing when it happens. Luckily, plant breeders have been introducing more and more seed-propagated Canna varieties in the last few years. Instead of overwintering potentially infected tubers from one year to the next, Cannas can be quickly and easily grown from virus-free seed each year. If you want to continue growing Cannas from tubers, just be sure to purchase healthy looking plants from a reputable source. Be sure your plants still appear virus-free at the end of the season before digging up the tubers for storage.