On Mar 8, 8:27*am, "Andrew Ostrander" wrote:
No plants
survive ten degrees in a container that I know of in the general plant
trade. *Maybe there are some Alpine plants, but they are very
specialized.

I've noticed that one person in my neighbourhood successfully overwintered
hostas in containers last year, just left out for the winter, and the air
temperatures here in winter sometimes go down to -40C. *So hostas seem to be
very cold hardy! (I'm trying it myself this year. *I sure hope it works..)

Just out of curiousity, how big were the containers? In the past,
I've been told that in order to successfully overwinter in containers
(zone 3a), the container should be a minimum of 3x3x3 feet. Sometimes
people here will put foam insulation inside the outside edge as well.
Storage in a garage or cool storage area is also an option.

As for the OP, different plants have different cultural requirements,
and gardening advice also tends to be regionally specific as well, so
no one book is going to tell you everything. You might consider
taking a workshop or class or join a horticultural club. Perhaps stick
to annuals in containers for now.
Dora