Teresa - Please consider going back and asking the owner if you can have a piece of the phlox. It's a great compliment to the owner!
My phlox just expand and don't seed at all. I bought four (three of each) from Blooming Bulb in early spring and was shocked and delighted to see them blooming already. I didn't take photos of the phlox shown here. They're just to show me where I planted each of them.