We are big fans of plants that you can't kill, which is why succulents are a no-brainer for every type of garden space, even when container gardening. Whichever you choose, their cool colours, shapes and texture will bring a modern feel to your outdoor space, and you simply need to pot them up in coarse, gritty soil, in a pot that absolutely has to have drainage, set them up in a sunny spot and then you can let nature do the rest.