Petunia is a genus in the family Solanaceae. More familiar members of Solanaceae in other subfamilies include tobacco (Nicotianoideae), and the Cape gooseberry, tomato, potato, deadly nightshades and chili pepper. Ouch is what I say!
Window boxes throughout the land are happy to show off their splendours enhanced by Petunia. Each colour is a soften pastel (‘pass-tell’ as they say in America).
To thrive, if you have not yet planted yours out, they need five hours of sunlight a day. There, you have been told.