i finally figured out why i seemed to be stumped by this ... i brought this up in some other post.. in some other forum ...in regard to the need.. in my MI ... to protecting pretty pots ... i can not leave damp/wet media in a ceramic pot.. or there is the potential... that when the GROUND FREEZES .... the wet media can expand ... and POTENTIALLY crack or explode a ceramic pot .. and that is complicated by whether the interior of the pot is also glazed ... so my solution is pot in pot ... and removing the media... letting the pot dry in fall ... and storing it empty ... in a different post about ceramic pots... i mentioned that if you are doing annuals ... they can bolt.. for lack of a better word ... and come august or so.. look really ugly ... and if you have them pot in pot ... you can have a number of pots of plants.. and switch them out ... if some get ugly .. or if you just want to change the look of the pretty pot ... i have little direct experience with intense pot culture.. you and babs are way out on the learning curve on that stuff .... and i dont feel i can even be in the conversation in regard to such ... and that is part of my hesitation in responding ... ken ps: i am also aware of peeps using pot in pot under maple trees.. so you can pull out the pot with the plant.. cutting maple roots ... and slip it back in ... though that guy was in horrible OH clay ... under norway maples... and he solved the problem by moving.. lol ... and taking his potted hosta with him... lol .. i dont recall drainage issues.. but presume in his horrible clay.. it was a problem ...

oh come on bkay.. you are one of two pot queens here ... lol ... media failure is based on drainage .. as the media compacts or breaks down ... water does not flow freely thru it ... usually defaulting to puddling.. and running down the edges .. eventually when you unpot.. you find all the roots that were in the middle.. dry rotted .. and are dead.. and all live roots are out at the edges ... with a plant in the ground.. this is when you would start seeing fairy rings ... how do you SEE that in a pot ... well.. take it out of the pot and look ... generally though.. i guess i wouldnt go more than 2 or 3 years.. depending on the quality of the media you started with ... ken

I have a ton of hostas in pots. After they lose their leaves in the fall, and hopefully before first hard frost, I put them in my garage. All winter they sit there in the dark with no water. I can't drag a hose out to water them because I've put away the hoses, and anyway the hose would freeze, so dry they stay. In the spring I get them out, hopefully before they come up. This season I had a death in the family and delayed getting them out into the sun. They had come up in the dark garage, without any water and without any sun on them. They looked as white as mushrooms. I put them out, watered them, and in a week or so they all turned green. No damage was done. Here they are today, late May, ready to be distributed throughout the garden. Their stored energy is amazing. I don't understand how they can survive the lack of care I give them in the winter. They always do, though. For those who don't know, the reason to put them in a sheltered place has to do with root and crown damage that can result from snow collecting in the pots. It will melt when there's a thaw, seep down into the dirt, then refreeze, destroying cell walls and killing the plant. They take up a lot of room in my garage, as I don't stack them on top of one another in case I delay too long in getting them out of there. Losing that garage space to pots is worth it, though. I value potted hostas for their versatility; I put them wherever I need some energetic green foliage, and move them around often. Some of them are quarantined plants that I bought two seasons ago, now ready to be put in the ground having shown no symptoms of disease. There's a large mature Abiqua Drinking Gourd in there somewhere that I am excited to plant, and two huge Guacamoles also ready for planting. Somewhere.

"the car can stay outside at night for a few weeks.. if need be .." My husband would disagree with that! But I do love that idea Ken. "as a general rule of thumb gardeners can simply add one zone to the designated USDA zone. For example, USDA zone 4 is roughly comparable to zone 5 in Canada." So your zone 5 Ken is similar to my zone 6 according to google. As for the woman I was talking about who kept her large ceramic pots outside---she told me she had several large pots outside for many years. In another location there was a row of ceramic pots that were buried approximately 8 inches. But all the pots were lined completely with styrofoam. Here is a writeup from the woman who kept plants outside in her ceramic pots. She provided this information to our horticultural society. I have a dozen glazed clay/ceramic pots filled with soil that are left outdoors year-round. These are substantial pots, not the terra-cotta variety, and range in size from 12” x 12” up to 20” x 20”. Some have boxwoods growing in them for over 10 years, others have perennials and some are strictly for planting annuals. The pots have been outdoors for over 25 years and none has ever cracked. The pots are protected against winter freeze and thaw cycles with 2” thick styrofoam lining the walls and bottoms. The styrofoam is cut into sheets (for square pots) or V-shaped strips (for round pots) and pressed against the side of the pots before filling them with potting soil. Gaps between the strips should be minimized, but this is not an exact tailoring exercise. The styrofoam should come up to just below the top of the soil level (as it is not attractive). I replace the top few inches of soil every year for annuals, every few years for perennials and boxwoods. When selecting plants for growing year-round, I choose those which are a couple of zones hardier than ours.