Everything I grow is in a pot of one size or another, and I've had pretty good luck over the years keeping things alive through the winter. What I do is I take some cheap shower curtains from the dollar store, and place them on the ground next to a wall. I then place all the pots I want to overwinter on this plastic curtain, and fill in all the spaces with soil from my annual and veggie pots. I don't allow this pot spot to extend more than three feet from the wall. I place boards around the perimeter and make sure that all the pots are 'burried' up to the rim. Essentially I've just created a temporary raised bed. Before the ground freezes, I give everything a final watering, cover it with a thick layer of newspapers, and then cover all that with another cheap shower curtain (you'll need to weigh it down with something).

If you don't have enough extra soil to fill in all the spaces, you could use tightly packed leaves, straw, or newspaper. I find that the soil works best, but the other things will help a fair bit. If you're just talking about a couple of pots, and you've got some actual ground, you could just dig a hole and burry the pots. If you have a cold room, or an unheated crawl space you could probably put the pots there too. If the pot is really big - 40 gallons or more - you might not need to protect it at all. One thing to note is if you try to overwinter anything in a terracotta pot, the pot will probably break.

BP

I've seen a few people on the forum in colder zones talk about setting up quick and inexpensive cold frames using bales of hay for side insulation and setting windows picked up at surplus stores, etc. on the top (venting as needed on sunny days or removing the windows). It sounds sensical to me -- the bales would likely have more insulative properties than, say, just a thin piece of plywood.

Here is a link that might be useful: gw search on

If overwinteing perennials, (or anything else) I strongly advise dosing the pots woth Provado vine weevil killer, - otherwise you will be providing the little swine with a nice cosy home for the winter, and they will EAT ALL THE ROOTS. I am not a Provado shareholder - just paranoid about Vine Weevils.

I take all my pots group them together and dump horse manure over them. They are on a cement area near my garage and also absorb the sun and heat from the cement during the day. My spirea,hostas, coneflowers,hydrageas,sedums,etc all lived over the winter this way.Come the spring I pot up the excess manure and clean up the whole area.