Terracotta Pot Care: Cleaning, Stacking and Protecting Your Pots From Winter Frost

— the kind of quiet heartbreak that only another gardener really understands. It had been sitting, still slightly damp, tucked against a north wall over a cold snap in January, and I found it split clean down one side when I went to empty it in spring. Terracotta doesn’t forgive that kind of neglect, and I’ve been much more careful with mine ever since.

The reason terracotta cracks in winter isn’t really the cold itself — it’s water. Unglazed clay is porous, so it absorbs moisture from wet compost or rain. When that trapped water freezes, it expands, and the pot simply doesn’t have anywhere for that expansion to go. A pot that’s bone dry going into winter will almost always survive; a pot that’s wet and frozen very often won’t. Everything below follows from that one fact.

Empty and clean anything that’s finished for the season. Tip out spent summer bedding, brush out loose compost, and give the pot a proper scrub with a stiff brush and water — a splash of white vinegar helps lift any chalky mineral deposits or algae. Let it dry completely before you do anything else with it; this is the step people skip, and it’s the one that matters most.

Store empty pots undercover if you possibly can. A shed, garage, porch or even just a spot under greenhouse staging keeps them dry all winter, which is really the whole game. If you don’t have covered storage, turning pots upside down outside is the next best thing — it stops water pooling and freezing inside them, though it won’t fully protect against a very hard freeze.

For pots that are staying planted and outside, raise them off the ground on pot feet or even a few flat stones. This lets water drain away properly instead of sitting in the base and freezing solid, which is often what actually cracks a planted pot, not the cold air around it. Wrapping the outside of the pot in hessian or bubble wrap adds a further layer of insulation for anything you’re particularly fond of.

Not every pot needs this fuss. Thick-walled, well-fired terracotta — the kind of English and European pottery that’s genuinely made for outdoor use — copes far better than thin, inexpensive pots, which is worth knowing before you buy your next batch. I’ve gathered the terracotta I trust to actually survive a proper winter, in the sizes I use most in my own borders and containers, on the English Cottage Living Planters & Pots page.

One more thing worth doing now: take a photograph of your pot arrangement before you empty everything for winter. It sounds a bit silly, but I’m always grateful come April to have a reminder of what worked well together, rather than trying to recall it from memory.

It’s a modest bit of housekeeping, but it’s the difference between opening the shed in spring to find your favourite pots waiting for you, or finding them in pieces. Twenty minutes now, spread across whichever pots you can get to this weekend, is all it really takes.