These flower pots are hand-crafted using techniques rooted in centuries of ceramic tradition:
Generally, only "high-fired" pots are able to survive the temperature changes and the freeze/thaw cycle. Examples of pots that don't make this cut are most Mexican terra cotta planters, and most Italian red clay pottery. Also, any pots or vases that do not have drainage holes should be brought inside.
Once you’ve determined that you have a flower pot that will most likely survive the worst that winter has to offer, it’s important to note that it’s generally not OK to just leave the pots in the same condition that they were in during the growing season.
Obviously, the best option is to bring your ceramic flower pots inside, or to at least cover them with a tarp. If those aren’t options for your containers, or if you really like the way the pots look, and you want to keep looking at them all winter, there are lots of things you can do to ensure that your beautiful pots continue to look great and last through the winter: