My question is....if I plant Hostas in cast iron urns will they survive the winter if the urns are left out in the elements or do they need to be dug out and placed in the ground? Ideally I'd like to leave them in the urns....but I'm doubting they would survive. I'm in Southwestern Ontario. moderator's note: added a more descriptive title to topic
How cold does your winters get? Will the soil freeze through? I guess the hardiness zones given for hostas are when they're planted in the ground. If you've got a piece of hosta you're not afraid to loose, then give it a try. Then you'll know.
You're further north than I am, and I wouldn't suggest it. There are very few things that would survive overwinter here in our zone 4...the only perennial that I know will make it above-ground is the Stella de Oro daylily, and the bigger the container the better. When I was in the landscape business, this is one plant that I would recommend to those who wanted to put something other than annuals in containers. Some Prunus species (cherries) also have cold-hardy root systems. I have mixed hostas in containers along with other flowering plants, but always transplant them into the ground in early fall. I still personally prefer to use annuals...flowering varieties will bloom ALL SUMMER LONG, and there are many annuals to choose from that are used for their foliage interest. How about caladiums, calla lilies??? Or bury your container with the hosta planted in it into the ground in the fall and then bring it out in the spring...the hosta will have a better chance of surviving if its roots are more protected.
I 'think' I'm in zone 6a the ground does freeze solid here. Cold...darn cold hows that for cold it can easily dip into the minus' here. I think I will go with my own hunch as well and transplant them into the ground for winter. Had extra hostas so I thought I would just throw some into the urns rather than the urns sitting empty to spruce them up <G> Thanks kaseylib...thats what I figured, but thought it was worth asking just in case.
I'm in zone 5b, Collingwood, Ontario area. In the spring I pot up and sell some of my perennials. Sometimes I have a few left over so they sit outside all winter long. Usually they have good protection thanks to a heavy blanket of snow. Without the snow cover, I'm sure I would lose a lot of them. It is the freezing and thawing that would kill my plants in containers so I make sure they get lots of snow cover. Urns are too tall to constantly keep them covered with snow.
The last few years we have had winters with many thaw / freeze cycles. I wouldn't recommend leaving Hosta's in containers for the winter if you are afraid of losing them.
