Why You Should Never Leave Terra Cotta Pots Outdoors All Winter

I’m posting this bonehead mistake I made for new gardeners. Know that you will always make mistakes, even if you’ve been gardening for decades, as I have.

I knew better. It’s physics. Terra cotta pots expand and contract with the weather because they’re made of clay (technically a clay-based ceramic). Therefore, you shouldn’t keep them outside all winter, where they’re subject to repeated freezing and thawing. The ultimate result may be a nice big crack that splits the pot wide open. Usually, sometime in October, I put them in my garage and store the flower bulbs I’m overwintering in them (dahlias, calla lilies, and the like). I did that with all but one pot this year and I paid the price.

Blame it on the hyacinths

It’s the hyacinths’ fault. I love them, adore them. Their magnificent flowers signal that winter is definitely behind us, and it’s time to start growing vegetables and other fun things. I have tons of hyacinths planted in my garden: short ones, tall ones, purple ones, pink ones, and white ones. They really put on a dazzling display.
But I want to enjoy their magical scent up close – I’ll admit it’s almost like a drug to me. So I also want a pot of hyacinths on my porch in the spring where the scent can waft over me while even letting the dog out to do his business for a few minutes. Sure, I could buy a greenhouse-grown pot of hyacinths at the garden center in April – I have many times, but I wanted a LOT of them on my porch next spring. So I bought a package of bulbs and arranged them in a terra cotta pot last November. I figured that I’ll add some pansies on top in April, and it will be wonderful.

Hyacinth bulbs need a period of cold weather to bloom

Hyacinths need a “cooling” period of at least 13 weeks below 40 F to bloom. So if you’re not planting them in the ground in the fall, you either have to keep them in a pot outside from late fall into winter or chill them in your fridge. I chose the pot outdoors.

Of course, I knew better. I should have used a plastic flower pot. But all were otherwise occupied or plain old ugly (I’m not pot-shaming, but I want something not garden-center black on my porch). Being the cheapskate I am, I didn’t want to buy another pot, so I decided to throw caution to the wind and use a favorite terra cotta pot.

Well, I was never lucky at gambling, and Mother Nature schooled me again. The pot cracked from top to bottom. And not just a superficial crack – this one runs all the way through. Now I have to buy a plastic pot for the hyacinths anyway and replace this beautiful, aged terra cotta pot that I’ve had for many years. I won’t make that mistake again. But I’ll probably make a different one.

From the pictures below, it may not appear that the crack is too bad. But it’s all the way through the pot to the point that it may fall apart. I carefully placed it into a larger plastic pot until I can replace it. Yes, it was one of those black garden center pots. That’s irony, isn’t it?