Although a wild flower, Eupatorium serotinum or Late Flowering Boneset as it is commonly called, has become popular for use in garden planting schemes to encourage bees and also to provide late season nectar for the Monarch Butterfly. It also attracts some species of parasitic wasps that can single-handedly reduce the population of the voracious Japanese beetle. The wasp lays its eggs inside the beetle which is then consumed by the larvae, when they hatch. Eupatorium serotinum, a member of the Asteraceae (daisy) family and native to the US, is a large, robust perennial often reaching two metres high in ideal conditions but is not invasive.
The bright, green leaves are spear-shaped and toothed and the stems are covered with very fine hairs making them look furry. The flower heads consist of up to 15 tiny, white flowers which have a lilac-like scent. The blooms arrive just as other summer flowering plants are beginning to fade in the autumn and give the butterflies an extra source of nectar when there is little about. The attractive flowering stems can be cut and used in both fresh and dried flower arrangements.
Propagation is by seed which can be collected by hanging the dry flower heads upside down in paper bags.
Eupatorium needs well-drained but moist soil although it will withstand some drought and hot, dry summers. It is similar to Common Boneset, Eupatorium perfoliatum, which is well-known for its medicinal properties and is used to treat intestinal worms, malaria, dengue fever, the flu and diarrhea among other ailments. It is also used to make banishing spells by modern-day Wiccans.