I can only say what qworks in my zone which is much colder. The two I have grown in the pond is Pink Sunburst and B. tiger. They were put in tghe pond after they had leaves 3' tall. If the water freezes or is below 40 the bulb will die.

I dropped the pot in the pond. It was totally under water

I have had cannas in my fish pond. This was before Hurricane Charley in '04. Never fertilized, just dropped the whole pot in water about knee high. They grew so huge they wouldn't stay upright, so I had to take them out and divide them. They were a gift from a friend, so I don't know what the name is. Put a lot of washed gravel in the bottom of the BIG pot, then fill with top soil (comes in a 40 lb. bag). Do this near the pond as it will be very heavy. Then plop it in your pond and it should take off! As for taking them out, I don't know about your zone. Mine have been exposed to temps in the high 30s, and lived to tell about it.

I have a 3 gallon pot.I can use my cracked ones for the cannas.I have a sidewalk I demolished.so have both small and large pieces(been sorting the small ones to anchor my lillys down in water).nice to know I can just drop the pot in deeper part for my brief winter..mine try to sprout up all winter everytime we warm up.I got a section been covering at night when drops down(hopein for sooner blooms)

Thanks!

I have a small cement fish pond in my backyard, only 1000 gallons or so. No dirt/substrate about 2ft deep.Floating water lettece, water hyacinth were in there happily. I wanted something showy & taller without taking up too much room. Read that Cannas LOVE water- so with an abundance of green leafed, red flowered "Sun" cannas I had around I decided to try it (didn't wanna kill my red n. Purp cannas if it didn't work lol). I pulled 3 cannas outta the dirt, rinsed roots really really well in a bucket of pond water and placed them in a milk crate sunk with a rock (my fish LOVE milk crates to hide in and I use them to hold plants upright in the pond) been 2 weeks so far and the cannas are thriving.