Question About Canna Rust

Wesley Chapel, FL(Zone 9a)

My Cannas have rust - no doubt about it.

They die back for the winter here in central FLA. We leave the rhizomes in the ground, and they come up again in the spring.

My question is, will they have rust when they come up again next spring?

Would it be worth the trouble of digging up the rhizomes, treating them with a fungicide, and storing them for the winter? Or just leave them, and hope the rust fungus dies off with the winter?

I Googled canna rust, but I can't find anything on it.

I appreciate your help.

Steve

Thumbnail by skaz421
West Central, FL(Zone 9b)

Steve , I don't know the answer to your question, but found a site that may be helpful.
I was thinking about planting some cannas, have only done a little research so far. Hope this helps.

Michelle
http://www.mobot.org/gardeninghelp/plantfinder/Pests.asp?genus=Canna&care=Canna%20-%20Hybrid%20Cultivars

The Woodlands, TX(Zone 9a)

It has been my experience that it is almost impossible to get rid of rust on cannas. Rust will live on dead tissue overwinter, and although I clean the beds after I cut them back, I can't get every little piece. In the spring the cannas look wonderful, then along come the leaf rollers, followed by rust. I cut them back to the ground, they regrow, and it starts all over again. If anyone has the answer, I would like to know what it is too.

Wesley Chapel, FL(Zone 9a)

I've read that fungicides will stop the spread of rust, and should be used as a preventative.

I bought a copper-based fungicide. I'm going to cut some Canna back to the ground, use the fungicide, see what happens.

Between rust and leaf rollers, I'm beginning to wonder if they're worth growing. Thank God the rust doesn't spread to any other plants, at least none that I can see.

Steve

The Woodlands, TX(Zone 9a)

Steve - I am in total agreement with you. Are they worth growing? This fall I'm digging mine up and giving them away. I guess I'm too lazy to spray weekly, one for leaf rollers, and another for rust... But I wish you the best! (Do I sound disgusted - and discouraged?)

Wesley Chapel, FL(Zone 9a)

I've been thinking of cutting way back on them, and make it easier to keep them. Maybe just 3 or 4 varieties next year.

Austin, TX

You are so right. Total pain in the neck. But when that orange-red dragonfly hangs out with the canna of the same color likes it's his cousin, it really is a beautiful sight. Sorry no pix as of yet.

West Central, FL(Zone 9b)

Steve,
Make sure you treat the soil well around those Cannas. From what I have read some harmful fungus types can stay in the soil and re-emerge even after freezing up North.

Now I did handle a fungus infection on my Passiflora Caerula early last week. The infection was at the soil line on the stem. I used a product called Grapefruit Seed Extract. It is sold as Citricidal for agricultural use. It's not cheap, but I had some already. So far the passiflora is recovering beautifully. I lost about half the plant in a matter of 2-3 days before I figured out it was a fungal infection. I put some drops in a gallon of rain water and drenched the soil. It does go pretty far. For good measure I sprayed the leaves with Safer's.

Here's a link:
http://www.biochemresearch.com/citricidal.htm

Wesley Chapel, FL(Zone 9a)

Shellabella,

Thanks for the info. I had already bought a copper based fungicide, and it was a little expensive, so I think I'll give that a try.

Good point on treating the soil around the plant.

Steve

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