Hello! My husband is building me a new chicken coop. I would like him to build some window boxes to put under the windows. They will only be about 18 inches long and then however deep and wide I need them to be.

Since they aren't that big, I would like to put some succulents in them that are hardy and won't need much water. I'm just wondering if they would survive the winter in a small box. The windows face south so they would get a lot of sun and a lot of freeze/thaw.

Do you know of any that would survive or would I have to bring them inside during the winter months?

Thanks!

I live in northern Utah, zone 5.