so far I have had good luck in these various conditions:
hardpan clay full sun, nothing extra except rainwater
loamy loose soil around an oak tree stump, full sun, mulched with grass clippings
part shade not weeded dry but dark soil
rich manured/composted moist part shade
rocky dry ditch that gets run off from the street
It is a nice hardy plant that can handle a variety of situations. I have E. purpurea, which does better in midwest taller grass prairies (or where they USED to be). I can grow E. angustifolia but it is shorter, lighter in color & more used to drier conditions farther west where the shorter grass prairies used to be.
deer like to eat the flowers, but it doesn't seem to bother it. it just keeps growing more....