Eupatorium serotinum

For about a month in late summer, this boneset’s attractive, flat-topped flower clusters become a gathering place for pollinators, and one can observe the colorful locals – moths, skippers, butterflies, wasps, bees, and flies – foraging within inches of each other. Due to the plant’s abundance in disturbed, urban environments and its nutritional value for a diversity of organisms, it holds an important place within the food webs of our modern landscape. One handsome creature that can often be found on late boneset is Scolia dubia, the blue-winged wasp*. With iridescent, dark blue wings, and two bright yellow spots separating its black upper body from its rufous hind portion, the blue-winged wasp is a visually striking member of the garden fauna. Bumblebees and butterflies are also drawn to late boneset, with the monarch butterfly showing a special fondness for the plant. In late summer during its southward migration, it is not uncommon to observe multiple monarchs nectaring on a single late boneset.

Growing best in moderately moist soils and under full sunlight, late boneset tolerates a range of conditions, especially when it comes to soil moisture. Within its native NE Ohio range, late boneset can be found in wetlands, meadows, abandoned fields, roadsides, and even gravel lots. In terms of growth form, the plant branches outward in its upper portion and also tends to form small, tight colonies as a result of rhizomatous growth. For these reasons it will often display a bushy appearance within several years of planting. Frequent naturally occurring associates of late boneset which bloom within a similar timeframe include panicled aster, New England aster, grass-leaved goldenrod, wingstem, and tall ironweed.

*Wasps do not behave aggressively towards humans when foraging for nectar. Instances of aggression are primarily limited to certain wasps (social wasps) that are defending their nest against a perceived threat.

Photo by Frank Mayfield.