It isn't invasive but if you don't deadhead the flowers before they go to seed you will have them scattered everywhere through the flower bed you chose to place them in.
Here you can see where this one is snuggling up to the varigated Weigelia bush. They complement the pastels in your garden. Or they can take a stand with the darkest brightest colors you place them with.
They will grow in full sun or deep shade. They aren't a bit picky about placement. A real bonus too is that they do well in a cut flower arrangement. I can't say enough good about these beauties. They are a real workhorse in my spring/early summer garden. The blooms last a long time.
Wildflower Wednesday is brought to you by Gail at Clay and Limestone through Greenbow and several other blogs. To find a wildflower for your garden go to Gail's to see everyone that is posting about Wildflowers.