Blue mistflower
Conoclinium coelestinum (L.) DC.
Also called blue mistflower, wild ageratum. Synonyms: Eupatorium coelestinum.
Late-season native with fluffy powder-blue flower heads like a perennial ageratum, crowded with butterflies and bees from late summer to frost. Spreads by rhizomes into loose drifts in moist soil.
Size over time
Typical landscape size 0.5–0.9 m (1–3 ft) tall and 0.5–0.9 m (1–3 ft) wide; fast growth, about 2 years to maturity. Intermediate sizes use the planner’s growth curve (k = 0.45) from the #1 install size.
Bloom
Powder blue flowers, Aug–Oct (northern-hemisphere months; timing shifts with region and season).
| Plant | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Blue mistflower : Aug–Oct |
Design notes
- Runs freely in rich moist beds — give it room or edge it; it is easy to pull.
- Cut back by half in early summer to keep it from flopping.
Regions
Native range: Eastern U.S., from New Jersey and Pennsylvania west to Kansas and south to Florida and Texas.
Native to these OpenLandscape3D pilot regions:
Native status describes where the species occurs naturally. It is not a promise that it suits a particular garden; site conditions decide that.
In the guides
Blue mistflower comes up in these guides:
Related plants
Try Blue mistflower in a plan
Opens your own copy of a finished sample garden in the planner with Blue mistflower ready to place; the planner checks it against that garden’s zone, light and moisture.
Plan with Blue mistflower
Place it in a design, check it against your zone, light and moisture, and see it at year three and year ten.