Blue Mistflower (Conoclinium coelestinum, formerly Eupatorium coelestinum) showed up on my floodplain about five years ago. I recognized it immediately from seeing it on my trips to the North Carolina Botanical Garden in Chapel Hill, and I was delighted to see it volunteer its presence beneath a deciduous holly in damp, sandy silt deposited by occasional floods from the creek that borders our property.
When it first appeared, it was even smaller than the plant pictured above. Creek-deposited volunteer wildflowers come and go on my floodplain, and I wasn’t sure it would last, but I needn’t have worried. A bit of research revealed that this wildflower spreads by rhizomes (fleshy roots), and even has a reputation for being a tad aggressive in fertile garden soils.
Over the past five years, this clump of Blue Mistflower has spread, but I think its location likely prevents it from any takeover plans. It is suggested as a good groundcover for moist areas, and that’s exactly what my colony is doing. From August through October, the base of my 20-foot deciduous holly is completely surrounded by this low-growing, long-blooming lavender blue wildflower.
It looks a bit like the bedding annual, Ageratum, that you see in all the garden centers. But this wildflower is not related to Ageratum, and it’s a perennial, relying on its rhizomes to resprout and spread every spring.
Our native pollinators love the flowers, which is all the reason I need to welcome this beauty’s spreading ways. Add to that the lovely, long-lasting blue blooms, which come when native yellow composite flowers dominate the Piedmont landscape, and now you have a reason to find a spot for this beauty too.