You make sure your pots are not cheap low-fired ones, or you use Mica pots from on-line places, e.g. Bonsaimonk, or you plant things straight into the ground, or you have a greenhouse, or a coldframe, or....

I see......so basically I have to have a lot of money, or plant them into the ground each year. Gee, what choices!

No no - you don't need a lot of money at all, just save your 'bonsai pot' money for 'finished' trees (fully trained and about the size you want them to stay indefinitely) and do get good Japanese ones. But for the years of training, use mica, like so many of us, because it's cheaper than ceramic, a lot stronger, looks good and comes in diff. styles. Coldframes can be made at home with scrap lumber too, if you get a little plan off the 'net.

Okay, thanks Lucy! I didn't know anything about Mica, I'll have to look for that. I also had no idea what a coldframe was, so I'll have to check that out further also. None of the books I have explain any of this, so thank you. :0)

You don't have to spend big $ for pots to make it through the winter. Unglazed pots tend to fair better and how you store your bonsai can make a difference. I overwinter in my unheated greenhouse and garage- no mulch around the pots. Also I pile snow or ice on top to water which melts only when warm enough for the trees to take the water in. If you watered & then they froze that could explain it. I've only lost one one pot in the last 3 years and it was a cheapo glazed from Sam's club. I also haven't lost any trees that were hardy in my area due to winter.

the pots were cheapo glazed pots that previously held cheapo store-bought bonsai trees....we have a lot of thaws & freezes & the pots just break in a hundred pieces :0) Thanks for the help.