Perhaps a Banana. A Dwarf Cavendish will not get too big.

Elephant ears will grow anywhere.Full sun,full shade,dry(but they don't look very good) or in a pond. PJ

Maybe you don't have to get rid of them;
maybe it isn't virus.

Worms eating rolled leaves sounds like canna leaf roller, which can be controlled by trichogramma (trichogamma?) wasps or BT (bacillus therengensis or some such).

I don't know how you can compost a canna rhizome;
I'd think it would be perfectly delighted to find itself in a compost pile!

LOL Sylvia you got that right.
I tried to compost cannas leaves and even they didn't break down after a years time.

Leaf rollers is all that's going on happens every year and if you want to spray to have pretty leaves then that's what you'll have to do or you can enjoy that fact that your plants are a host to moths :)
This site might be helpful

Here is a link that might be useful: lesser canna leafroller - geshna cannalis

PJ's right...I have elephant ears planted with my Cannas, they are just as tough, and love the sun or the shade. You could consider keeping the cannas and just adding the elephant ears for camoflage of nibbled canna leaves...I don't pamper my cannas at all, but the EE's get tall enough and spread out enough to kind of hide the rough edges on the cannas...

Canna's are also host to the Skipper butterfly. They aren't a real showy or colorful butterly, but I like to see them zipping and skipping around the garden even if they do leave the canna leaves in tatters.

Some of the species canna with smaller flowers are very resistant to caterpillars. Schumachers in New Braunfels has them and Yuccado sells them by mail order. The hummingbirds especially love the species and the foliage is very nice.

As to what to plant in place of any canna the ideas above are great. There is a short yellow flowering banana plant you might look for. I don't remember the name of it. I have a picture somewhere or you can do an image search on google.

This is the bloom the flowering banana. There is a clump of them outside the S.A. Botanical center on the far left as you face the entrance. I had it for several years, it produced offshoots and then one year they didn't come back. Amazingly the bloom lasts for a couple of months.

It's certain. They do have canna virus so they are pretty much terminal but will go a slow and unattractive death. They are already on the way. Keeping them isn't an option. I agree with Sylvia. A compost pile would be heaven for a canna so I was going to wait for winter, dig them, and leave them to freeze on top of the pile before turning them under.
Canna leaf roller is the other problem. These cannas are in a prominent spot and they look bad enough already.
I hadn't considered elephant ears or a banana. It is pretty windy but dwarf varieties might be tough enough to stand up to it.
Thanks for all the input.

One more plant to consider...Strelitzia "Bird of Paradise". They do fine unprotected for me in the north of Houston area, but they may need a blanket thrown over it for your 8A.

There is a yellow flowering bird of paradise, but it grows into a small tree.

This really sounds like just leaf rollers - never heard of cannas getting a virus, but I'm sure verdant lady checked it out with her local master gardeners or some other plant expert.

I like the idea of the elephant ears. I have a clump of them that look great the whole summer and receive a little extra water when the neighbors turn their sprinklers on.

what look are you going for? Do you want tall? Do you want green? I have these tall purple reseeding celosia that have purple flowers in the fall. They like sun, aren't fussy, have loads of leaves so if something eats some, you just cut them off and there are 2-10 more underneath.

Other than that, I have elephant ears and that type of tropical in with my cannas. Mine don't get enough sun, and I've tried to get rid of them a couple of year, then just gave up. The elephant ears are happy there. But again, if I had more sun, I'd replace them with the tall celosia. I can give you lots of seed in late fall or if you want to try some. I could dig you up a few now.
cynthia

The tall celosia sounds interesting. I was looking more for the large leaves for a tropical look. But I just might do a mixed bed. There have been some really good ideas here. Thanks guys.

Yes, denisew. They have leaf rollers but that's in addition to the canna virus. Two separate problems. If it was just rollers I wouldn't be giving up. But after the leaves began to yellow, streak, and die I found the photos below when I was trying to discover what was wrong.

I checked with two master gardeners and a knowledgeable nursery guy. They all just shook their heads, and said 'No hope. Get rid of them, they will just die anyway and be ugly about it.' I was hoping that my cannas were just needing iron or something. No such luck.

The thing is that they looked great for three years after I planted them and then I bought a new plant at Lowes. That plant is what brought the infection in. It was on the discount rack and I thought it had just been abused and needed some TLC. That's how I get most of my plants and usually they are just fine after getting some extra attention. This time I wound up bringing a disease home.

Here is a link that might be useful: Canna Virus photos

I'd consider pulling the entire plant out now and disposing of them. Get the whole thing even the rhyzome. I think you'd want that virus out of your yard as soon as possible. Even wash the shovel when you are done.

Who knows, you might want to grow canna again and you don't want any trace of that virus in your yard if you do.

I'd be happy to share some rhyzomes in the spring that are virus free. Or you can grow from seed. I've got a whole crop of good looking canna coming up this year from seed. The virus, by the way, is not known to be able travel via the seed.

So as far as I know, seeds are safe. I don't think I'd risk another store bought canna.

Good luck,

Banana Mike

Oh man, I hate to hear about that virus. I battled the leaf rollers last year & it was a pain, but got rid of all the debris last fall & this year hasn't been bad at all.