I am growing French sorrel, which is a perennial. I bought mine as a small plant and had it growing in the ground for about a year. It did well throughout the summer, and set some seed which I promptly cut off because I didn't want the plant to die or the leaves to become too bitter. Then I decided to move my garden so I dug up the plant and moved it into a large pot, where it is now doing very nicely. Last winter it provided fresh leaves all winter, and my only problem was finding someone who wanted to eat them. I now have a friend who likes sorrel, so that shouldn't be a problem. French sorrel is a very attractive plant and is not invasive, but I don't know about red sorrel. Edible pods that taste like cranberries certainly sound interesting, though.