Cannas, at least the ones NOT specifically sold as "aquatic cannas" (although I'm not sure there is really a difference), do not like to be soggy in the spring when they first start to grow. Soggy cannas are prone to rotting. Once they get going and have some leaves on them, they can tolerate lots more water. I would recommend leaving it in the pot, and removing the pot for the winter and storing like any other canna. Also, you will need to elevate it. It's not going to like being 4 or 5 feet down at the bottom of your pond. A couple inches over the pot is the most you should do, and almost level with the water surface is even better.

This rose sounds like it would benefit greatly from a change in location. Increased sunlight, ventilation, etc. Although all my Darby's are zone 5 hardy, they are in prime real estate. I think it is a toss up between moving it to a large pot and letting it settle in before the frost OR babying it in it's current location. The ability for a rose to tolerate winter depends greatly on the health of the plant. I have overwintered many tender limping along roses and i must say they fare better in the garage. If you can leave the root ball intact when moving it, dig as far out as practical, disturb feeder roots as little as possible, then I feel the gargage may be the best bet for next spring.

whats in the pots??? soil/dirt .. or potting soil? if you have multiples.. i suggest you try a variety of methods, rather than investing in one method.. which may or may not work .... in other words.. experiment ... i only have experience in sinking pots with native soil ... sand.. which is never a drainage issue ... i see the following issues: drainage wetness at the roots heave of the pots timing sunlight on dark pots and i am sure more than that ... i know a hosta guy who has hosta seedlings in trays .... of course shorter than your stock ... he simply pulls a cover over railroad ties.. with chicken wire for rodents.. and plenty of rodent bait ... you might try some bails of straw .... around a group of pots .... and then some lose [key word] straw around the pots to protect from sunlight ... this will reduce wind.. and sun ... anything that is heavy is not recommended .. like un-shredded leaves .. light and airy is the idea ... good luck ... and as noted.. do NOT put ALL YOUR MARBLES IN ONE BUCKET ... ken

Sunshine, my Oscar Tintori post had nothing to do with you. People on this forum seem to have negative positions concerning terracotta. I, as you, like growing in terracotta, Personally, I have never had any problems with terracotta. Going to Tintori's web site one can see all of Oscar's trees and the lovely terracotta container s they are in. Few in this world have more knowledge and success with container citrus than Tintori.