There's also the Canadian forum and there are folk there from the even-cooler zones who can probably help with very pertinent suggestions. Worth a go (and they're generally very nice, too).

Lining with styrofoam may help when using large plastic containers. Moving the container closer to a warmer outer house wall may also keep small trees from suffering too much.
I haven't done this but it's what I would try.
Perhaps an internet search will find a discission on this!

The plastic containers don't stand up well to sunlight, lasting only a year or two if left out all year. Pottery will crack, cement will flake. I have found the best to be fiberglass (also expensive)

However, it is highly unlikely that you will be able to keep perennial plants or trees growing in containers that are left out over an Ontario winter. The roots will freeze in the container and likely the plant will die.

Moving the container into a garage for the winter or covering it with a foot or two of straw might keep it going. Generally, you are better off planting annuals in containers in Canada.

Thank you,Judy..

yes, slowly but surely,by doing a little research, i am coming to the conclusions you have mentioned..Thank you for taking time to post.

we have found some durable fiberglass planters, plan to plant annuals, and then empty planters and keep in garage over winter.

thank you once again
alice

Night & Day Pottery Studio in Mount Forest, Ontario make frost proof terracotta planters. I've used them quite successfully.
Night & Day can be reached at http://www.styll.com/NADS.htm. This is the website for their store in Elora, which includes some pictures of their work. The plants we have grown in terracotta perform exceptionally well - they seem to really like the pots and the pots & plants have fared well over the winter.
We leave most of the plants we grow outside overwinter - mostly in plastic pots. If you have a good snow cover, there is no reason most plants won't overwinter. Without a snow cover, it becomes a little more difficult, but not impossible. We have experimented with hundreds of different varieties this way, including lots of plants that are not considered hardy here with great success.

thank you so much ninamarie..

i really appreciate the information..

we just tried ordering some heavy duty pots.
fiberglass, i think
.i thought they would not break as they are s synthetic material..but they smashed in transit..

so ..we will look into a different avenue.

terracotta may be the way to go..altho they are breakable also..
well, we are just feeling our way here.

many thanks
alice

Alice
I would suggest phypon containers. They are about as durable as you can get.

Vickie

Thank you vickie..

i need to do a Google for the substance you mentioned.

thank you for taking the time to respond

alice