Whether or not an Olla can be left in the ground all year really depends on where you live. Here in Tucson, it’s fine to leave them in the ground all year. But for locations where the ground freezes solid, it’s a good idea to dig them up for the winter.If you take them out of the ground for the winter, store them in a dry place and make sure that they are empty. It’s also a good idea to wash out any debris that may have accumulated inside the Olla and scrub any dirt off the outside. Now you’re ready to start afresh the following growing season.