"To prevent cracking, terra-cotta containers should be brought indoors before frost," says Spence. "Empty the containers of plants and soil and store them in a frost-free place." (Here's how to clean those terra cotta pots.) Fluctuations in humidity can make containers that are nested inside one another swell and stick together. For winter storage, Spence suggests setting the containers upside down on a level surface and then placing pieces of flat scrap lumber across them to create shelves on which other pots can be stacked. "This prevents chipping and still allows you to store several pots in a small space."
If a container eventually cracks, all is not lost, insists Spence. "I break the cracked pots apart with a mallet and plant succulents in the larger shards and place the smaller ones in the bottoms of pots for drainage."