I almost always agree with Daisy, but potatoes grown in the ground definitely get more than a foot tall... German Butterballs grow to over 3 feet high in my garden, and other varieties get nearly that tall as well. (In full sun.)
I was going to ask the same question about whether yours is in full sun, Britnay, because it looks somewhat shaded in the photo (but that could just be the time of day, of course). At any rate, I don't think the plant is growing all that much larger than would be expected -- it appears taller because the container isn't as crowded as I've usually seen them -- good for you, Britnay, because I think that's the biggest problem people have with growing them in containers, trying to put in too many plants.
