Butterbur

Petasites hybridus

Characteristics

Butterbur, a perennial in the Asteraceae family, is a herbaceous plant that invades shaded areas with moist soil, including river banks, shorelines, wetland edges, forested floodplains, and roadside ditches. 

• grows up to 2 feet in height
• round to heart-shaped leaves that are 1-2 feet in diameter with dense hairs on the underside
• upright, flowering stem with no leaves above the base, hairy
• flowers are pink-purple and disk-shaped, arranged in a dense spike on a stalk with up to 50 flowers, blooms in early spring
• fruits take the form of a pink-purple achene, up to 3mm in length

KISMA Management Practices

Butterbur spreads easily by rhizomes as well as seed production. KISMA has been managing a half-acre butterbur area in Chassell periodically since the summer of 2021, and the results are looking optimistic.

1. cover portions of the knotweed plant with tarps or repurposed carpet pieces to reduce photosynthesis and to act as safe spots to place removed plant material to dry in sun
2. repeatedly pull or cut aboveground butterbur plant material every 2-3 weeks throughout the growing season over multiple years

Note: The purpose of this removal strategy is to starve the rhizome system of any carbohydrates that would be gained by photosynthesis and will require multiple years of surveillance and removal of plant material to be successful.

Examples of Areas Managed for Butterbur around KISMA

Native Alternatives

Species such as red osier dogwood (Cornus sericea), joe pye weed (Eutrochium purpureum), and swamp milkweed (Asclepias incarnata) are great native alternatives as they all thrive in environments similar to butterbur. It is important to replace butterbur with native alternatives to keep it from growing back after removal and to cover up exposed topsoil.