Whether empty or planted, clay pots should be left outdoors through the winter only under certain conditions.

Even the smallest hairline crack is enough to cause a clay pot to burst in winter – even if the terracotta is declared “frost-resistant”. Water can penetrate through small damages that easily occur unnoticed when handling pots and moving them. If the water freezes in winter, it can crack the pot or at least cause the glaze to peel. In particular, frequent freezing and thawing is unfavorable for clay pots.
For a long life, clay pots should therefore, if possible, always be wintered frost-free or at least under a roof. If this is not possible, it is advisable to place them elevated (e.g. on wooden slats) so that they do not freeze to the ground – and upside down, so that no water can collect in them.
Clay pots are a beautiful and timeless way to bring a touch of nature into your home. However, if you want to keep them looking their best, it’s important to remember that they should not be left outdoors during winter. Clay is porous and can absorb water, which can cause it to crack or break in cold temperatures. Additionally, freezing temperatures can cause the glaze on the pottery to crack or flake off. To ensure that your clay pots last for years, take them indoors during the winter months.
If a clay pot should break after all …
… then it is hopefully also no drama. After all, shards bring luck! In addition, larger shards of clay can be reused as creative planting bowls or integrated into the “wild” corner of the garden as a shelter for beneficial insects.

I have 30 years of experience and i started this website to see if i could try and share my knowledge to help you.
With a degree a Horticulture BSc (Hons)
I have worked as a horticulture specialist lead gardener, garden landscaper, and of course i am a hobby gardener at home in my own garden.
Please if you have any questions leave them on the article and i will get back to you personally.