University of Maryland Extension

Blue Mist Flower, Hardy Ageratum

Ellen Nibali

Conoclinium coelestrium

Blue is not a common bloom color this time of year.  Yet hardy ageratum, with its fuzzy-headed old-fashioned look, adds its blue-purple toned flowers and attracts butterflies to the garden from late summer until late in fall.  Native to the eastern U.S., hardy ageratum looks similar to the more-familiar annual ageratum.  Easy to grow, this 18”-24” perennial prefers full sun, though it will tolerate some shade.  It’s not picky about soil or pH, though it likes some moisture.  It spreads slowly into a nice patch, though where too happy it can require serious control. 

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