I'm no expert on canna viruses, but here's my two cents on the subject. There are two viruses that I know of. Bean Yellow Mosaic and Canna Yellow Mottle virus, though I believe the latter is the virus giving us so much trouble in the USA. These viruses are becoming more widespread every year and are very much threatening our collections of cannas. I first became aware of it/them 4-5 years ago after receiving diseased cannas in a trade. The first cannas looked kind of cool. They had some almost neon green steaks running through the leaves (Intrigue and Red Stripe cannas) and were quite beautiful to begin with. Later on they became distorted, stunted and had brown and dying leaves. New plants came up very stunted and strange looking. Eventually I wound up digging the plants and throwing them away, as the new plants coming up all appeared to be infected. The same year, and the next couple summers, I received several more trades of diseased cannas from traders here on Garden Web, though nobody seemed to know what was wrong with them.

There was little information on canna viruses on the net in those days. I had no idea there was such a thing as a canna virus. I'd grown cannas for 15 years and never seen sick cannas. Even now, there isn't much information on these viruses. I believe it is becoming a world wide epidemic though. You only have to go to Lowes, Wal*Mart, or Home Depot to see that nearly every canna they have for sale is diseased. Yet they keep on selling them. To date I have bought diseased cannas from Horn's Cannas and also from A Touch of Nature. I am getting to the point where I am afraid to buy or trade for new cannas. I want to protect my collection as much as possible, and I fear new plants as being a source of infection to my existing collection. In the early years I did not know to sterilize my pruners, knives and shovels in between each plant. Now I have become very diligent at sterilizing my tools and protecting the cannas I have. I have probably received diseased cannas from 5-6 traders, so be very careful trading, and be especially careful buying new cannas. I recommend buying growing cannas so you can see the foliage instead of buying dormant rhizomes. Who would have thought I'd receive diseased cannas from Horn Canna Farm, whom I've bought beautiful cannas from for years? I wrote to them last summer about the diseased cannas they sent me, and was very disappointed with their response to me. They stated:

Thank you for taking the time to contact us regarding the virus symptoms in your cannas.

The canna virus is something that is fairly new to the canna industry and there is much speculation and unknown about the causes. While there are some precautions that can be taken, there is no known cure at this time. It appears that cannas grown throughout the world are affected and not just those grown in Oklahoma or the United States.

This is our advice:

-Give the cannas the best growing conditions possible, and it sounds as if you are doing this already

-Apply a systemic insecticide to keep sucking insects from transferring the virus.

The cannas will grow more vigorously as the weather continues to stay hot. You may cut the unsightly foliage off and the cannas will grow out of the virus symptoms with fresh, new leaves.

If you would let us know which cannas other than the Miss Oklahoma and Pink Beauty are affected, we will be happy to replace these cannas for you for Spring 2006.

Again, thank you for contacting us. Please let us know how we may help further.

Horns did replace the cannas for me this year, but to be honest, I am scared to death of those new rhizomes and am thinking of digging them up and throwing them away. They are not worth the risk to my existing collection. I also disagree with their advice to "cut the unsightly foliage off and the cannas will grow out of the virus symptoms with fresh, new leaves". My advice is, if it looks diseased, GET RID OF IT! I only have one canna left on my "Absolutely Gotta Have" list, and that's Panache. I am tempted to buy it now, and to then end my canna collection with it, never buying or trading for another canna. I know I sound a little paranoid, but cannas are my very favorite plant and I'd be so very sad to lose them, like in the case of Ian Cooke's famous collection of cannas which had to be destroyed due to these viruses. I love cannas, and I would like to see something done about growers selling so many diseased cannas. They do not care that they are infecting the world's collections of cannas. The same thing is happening with hostas and the Hosta Virus X (HVX), but don't get me started on that! :)

I'd agree that you shouldn't take chances with growing virus-infected cannas, even if the distortion isn't too bad, because the infection can spread to healthy plants (either via sap-sucking insects or by other means of contamination). Last year and this, practically EVERY canna tuber I bought here in the UK turned out to be virused (distorted, yellow-streaked leaves, brown patches, stunted growth). It's really disheartening and infuriating - the knowledge is out there, but retailers continue to send out virused stock. I posted a question about virus to this forum but there wasn't much of a response, so I got the impression that perhaps virus wasn't a big problem in the US.

I just bought a couple of Princess Di cannas from Home Depot ... both infected :-(

Couple things about the virus. It seems to be spread via tissue contamination only (ie sap from one infected plant touching another). Therefore be careful to disinfect pruning tools between plants. An infected plant can grow a foot from a non-infected plant and not become infected, but insects that suck on the infected plant and then on the non-infected one can spread the virus. Seeds produced by the infected plant seem to be virus free, however only wild speices of cannas can be propagated by seed (ie indica, compacta, etc) as seed from Hybrids (eg any named canna) will not grow true to form - though may resemble the parent so if you have a severely diseased parent that you really really love you can try to grow the seeds and hope you get something similar.

If you buy rhizomes, grow them in pots INSIDE or at least away from your canna collection till they reach 8-12" (3rd/4th leaf). If they look infected pitch them. If the virus doesn't show by then you should be fine and can plant them amoung your disease free collection.

The virus is wide-spread amoung many growers and it does seem that the cheaper packaged cannas being flogged by the big boxes are almost always infected. On the plus side the virus is relatively easy to quarentine if you're smart about it.

wolfover wrote: "You only have to go to Lowes, Wal*Mart, or Home Depot to see that nearly every canna they have for sale is diseased. Yet they keep on selling them."

Oh great, I wanted to grow Cannas for the first time this year. Walmart had a deal for a bag of 20 rhizomes. I figured we could try them and not invest to much money. Now I read this. How do I know if mine are infected? I might be trying something new and thinking we failed when in fact they were deceased to start with. I was going to try them in different sunny areas of our yard to see where they did best (zone 6).

Any info on how to tell if these are infected? Is this true that Walmart, Lowes and Home Depot purchased cannas are known to be bad overall ?

As far as dealers selling infected plants, there have been many reports of bad plants being sold. I have bought many from Walmart and Lowes and only two have been infected.

To help ensure you dont spread the virus you will need to make sure you sterilize your tools when moving to a different plant. 10% bleach should be fine

When receiving plants from a trade or store, grow them in a container until you are sure they are healthy.

This Virus is huge threat to the plants. Ian Cooke had to destroy his entire collection due to the virus. It's a sad, sad story. If you don't know who Ian Cooke is look him up and read his book, you should consider yourself "almost expert" after you have read it.

Here is picture of a plant that I suspected of having Yellow Mottle:
{{gwi:530717}}

Thanks everyone! I feel equally paranoid. I just got 2 new ones and I've got them isolated for now. I threw one cheapo I got from walmart in the trash in a triple-sealed bag because I didn't want to risk it. These new babies cost alot more and I want to make sure they're healthy.

Zitro_joe, what is the name of the canna in your picture? I was just trying to figure out if it was a red-leaved one to start? Anyone else have pictures of infected cannas so I can get better at ID'ing it? Thanks again.

I read an article about lilies this morning, and the author recommeded soaking lily bulbs in a 5% bleach solution for 15 minutes to kill any viruses before planting. Do you think this would work with canna tubers?

.... and yet some cannas have striped leaves. ....healthy ones at that.

jroot,
correct some cannas have stripped leaves, the different types of tissues that cause the strips are called chimera. However, it is important to know about this stuff. the picture I posted earlier should not have strips in the leaves - at all!

the virus is caused from grasshoppers eating and leaving droppings inside the leaves.once your cannas get infected the virus will spread to all plants,because the bugs that eat off the infected plant will spread it to the next. when I have a infected plant I dig it up cut off all the bad spots on the root ,cut all the black roots dip in a bleach bath,then plant in a separate container and watch it for a year. the next season you can replant in your beds. This has worked for me many times, I am not sure if you should try this (or even trust cannas bought with the virus)but if you do buy some better go ahead and bleach and plant is small pot and watch for a season. all my new plants get dipped in a copper bath before I ever plant them. seems to work. Happy cannas, Snowbird02

Actually, the virus is not caused by grasshopper - it is transferred by the grasshopper. Same with aphids, leaf rollers and earwigs.

For any one not familiar with the issue.
http://cannanews.blogspot.com/2008/01/thoughts-on-virus-from-hart-canna.html

The industry continues to sell infected plants because suppliers continue to grow infected plants. I have been told that some of the major growers in the US and Holland solely grow cannas and can't afford to take the financial hit of throwing away their stock and starting over.

Almost every Tropicanna for sale in my area was infected for the last couple years.

Luckily, I have several plants that are not. I really like Tropicanna.

Be careful and use bleach to clean your tools between plants.

If in doubt, ask here for advice and suggestions.

:)

Well, this grower when she saw her beautiful new hybrids contracting virus a few years back .. made the decision to destroy every canna she had that showed virus and focus towards growing a healthy collection once again.
She will never recover the losses, but for the love of growing cannas and preserving their future, it is worth it. Growing a healthy collection again has been wonderful to see.

I applaud you. It was very tough for me last year to throw out several of my cannas for that reason too.

This year, instead of ordering more, I'm going to see what is out there. Had to throw out my Gold Tropicanna, some Pink Sunburst and another one who's name escapes me right now.

I wonder if Canna Pretoria is in fact infected - even though it has a cool pattern.

I don't think there are many suppliers of cannas in Canada; excluding the packaged tubers.

I'm upset at the attitude of the suppliers and distributors towards the affect of the virus.

Many Retailers, like Costco will give customers refunds when they purchase infect plant material but this is not good enough - they shouldn't sell it in the first place. Staff at the big box stores are not educated in these disease issues because this would mean that the stores would have to stop selling the cheap infected stock including hostas with HVX.

Think about all those customers that purchase plants not knowing anything of these diseases and infected their collections.

shame.

I feel the same way you all do about the retailers selling diseased stock. When I first learned of the disease two years ago, I panicked and threw most of my cannas in the trash! I had a beautiful and healthy princess Di which I bought from walmart as well as pink sunburst, tropicanna, bengal tiger, stuttgart and several others from other (some expensive) sources.So I decided to place an order with a mail order nursery. ALL of their cannas were infected, which infected all of my cannas. I was heart broken!!
But I did not give up my love for cannas, now I only purchase plants that are growing in their pots at reputable nurseries instead of rhizomes and even then, I grow them away from my collection for several months until I know for sure that they're fine.
I don't mind spending a little more for a canna that's growing and shows no sign of the virus than a cheap one that will wipe out all of my collection!
I'm also a lot more careful about my handling of each plant. All of my tool get sterilized from one plant to the next and do my best to control the sucking/chewing insects as well.

It is tough to get rid of a canna.It is even tougher to cull many cannas. I worked very hard to get some of the rare varieties I let go and it was heartbreaking. Heirlooms, favourites, new hybrids, ones I coaxed to grow from a barely alive rhizome, it was very hard to be done with them.

Clean Pretoria, Pink Sunburst, and Durban exist. The virused with the variegation streaked look different from clean plants. If you saw them side by side, you would know.

I am posting a photo of a leaf I suspect of having the canna virus. I found photos online that look similar to this leaf.

Here is a link that might be useful: leaf could have virus

I kept the plant going and now it looks great, the discoloration is all gone. I had a virus with a hydrangea and with a hosta, but I think the canna one was a false alarm.

Here is a link that might be useful: Orange Canna recovered

I'm not so sure that the virus would be gone. I see streaking the lower leaves. Perhaps conditions are just better for now and the signs are somewhat suppressed. I would be hesitant about having this canna near others.

On the other hand, perhaps there was a nutritional issue and not a virus that created the signs in the first place. Or an environmental one that had an affect on the leaf development; and this is why the upper leaves seem to be uniform and "sign free".

You maybe correct that it was a false alarm but I would watch it throughout the season and see how you feel from there.

It does look good.

:)

Wow, I had no idea about the virus. I have native yellow cannas from here in Florida and beautiful tall reds, that are al very healthy....I so wanted some orange, I don't think I'll take the chance now....eeeek, I'd hate to lose my healthy ones, the yellow I've had for like 10 years. (I did see some (orange) growing in a ditch on the hwy...been there for years...I bet they are healthy ;)

I bet they are too!

Go for it!

:)))

Good luck, it sounds like a lucky source for a healthy canna.

I'm down to three virus free types and I'm nervous about adding any more. Maybe I can find a clean one growning in a PA ditch someplace! hah hah

But.... I was just on the blog of one of the previous posters and I think I found a source I can trust.... we'll see how the budget looks next spring.

I have all my virused cannas in one pot and all my good ones in others, very far apart from each other. As I see virused cannas, I quickly pull them out. One pot has a virused canna so I pulled it out and I dont think I will take that pot inside this winter (leaving it to die).

Is it normal to have some cannas in a clump grow more robust than others? I have one pot of cannas with some plants blooming at 4 or 5 feet high and some other cannas (of the same cultivator), in that same pot blooming at heights of 2 feet. Hoping its not a virus!

I bought a tropicanna last year from Lowes and through even this summer it has grown without any visable problems. I bought a black one a couple weeks ago from a local nursery and it turned out that after spending a couple weeks noticing its growth to be odd, that it was diseased. I have thrown it in the trash, luckily it grew far from my canna and my neighbors.

Locally I have noticed most cannas in nurseries are diseased now that I know the traits. I have to wait to see if my other canna was contaminated by pruning off old flowers, though I don't recall having to cut any off. I didnt realize this had all gotten so serious.

How is the wholesale trade keeping thier stock alive to even sell them? I would almost think it wouldnt be long before they have nothing left. I had hosta that had virus before among roses and even black eyed susan. Gardening seems too difficult these days with a global plant market distributing out of one place. There are no guards in place to protect our plant supplies and communities.

I have a feeling that cold regions probably have the least diseased material since here many people don't plant them yard to yard for which I am thankful. My neighbors have huge numbers of a heritage canna that has been in their family for years so I am trying to keep my yard clean for them too. Isolation by being zone 5 is my only comfort at the moment.

Well, I guess it would appear that my cannas are infected. I had no idea of canna disease until I was browsing this forum. Of course, mine were purchased in the bag at Walmart. They are pretty orange ones & watermelon colored ones. I'm not familiar with these plants, so was not aware that the streaking in the leaves were from a disease & not just the characteristics of the plant. They don't have any disfiguring (yet), but have had leaf browning from the tips back on a few, but they bloom well in the pots they're in. So sad that I have to destroy them, but I'm glad to be aware now.