The extraordinary size and silvery-blue color of the leaves of cardoons—let alone their fountain-like array that's sometimes as large as the canopy of a palm—make them irresistible. Plus, plants can succeed spectacularly both as annuals and perennials.
I've always grown this architectural beauty directly in the garden. The straight species of cardoon is a monster—OK, a space hog—so when I had opportunity to grow the more compact Porto Spineless form, I jumped at it. And why not in a container?