On top of the bike shed! Tall enough to keep tiny fingers away, close enough for me to water and harvest easily! This position had an invaluable bonus: visible from the kitchen window in our upstairs apartment, I look out on it daily. I see it every morning and think, "Really need to water those petunias," or, "Maybe I'll use some of the tarragon in this potato salad," et cetera.
Unlike the rest of the backyard, or most of Vermont this growing season, the environment on top of the bike shed was dry and hot. Next year maybe I'll put the petunias somewhere else and try some Sungold tomatoes.