This is a great flower for containers. It's called Calibrachoa but is also known as Trailing Petunia or Million Bells. The blooms are petunia-like in shape, just a whole lot smaller. You know how petunias are sticky? I hate that. Well, these aren't. And you know how you have to pinch back the spent blooms on petunias? I hate that too. Well, you don't have to pinch back or deadhead these. They keep blooming and blooming and ask for nothing in return but plenty of sun and water. Calibrachoa is an annual and it loves good drainage which is why it's ideally suited for containers. Million Bells looks like a million bucks all summer long.
Bookshelf: Container Gardening Books