Buttonbush
Cephalanthus occidentalis
Care
full sun
moderate
Fast, Medium, Slow; Tolerates a wide variety of soils and drainage types.
3–20ft tall , 3–15ft wide
Jun-Nov
Deciduous
Resistant
Yes
Prized
Eastern North America; not native to California but occasionally planted in riparian areas.
Care Guide
Planting
Plant your buttonbush in full sun in a location that stays consistently moist - ideally near a water source, stream, or low-lying area that naturally holds moisture. It tolerates a wide variety of soil types and drainage conditions, so soil preparation is minimal; just ensure the spot won't dry out completely. Plant in spring or fall when the plant is dormant. Space according to your desired mature size, keeping in mind buttonbush can reach 3–20 feet tall depending on growing conditions.
After Planting
Keep the soil moist through your first summer; this is the most critical establishment period. Once established, buttonbush needs only moderate water and can handle the Bay Area's drier months, though it will perform best if you don't let it completely dry out. The plant is deciduous and will drop its leaves in winter - this is normal. The #1 mistake is planting it in a spot that dries out; buttonbush thrives with consistent moisture, so avoid hot, dry microclimates.
Endangered & Threatened Species Supported
California Species of Special Concern; monarch populations declining
California Species of Special Concern
Wildlife Supported
Insects
Critical fall migration fuel source Aug-Oct; spring breeding population Apr-Jun
Confirmed host plant for specialist moth larvae feeding on flower buds and stems
Multi-brooded; nectar source Apr-Oct for adults
Day-flying hawkmoth; nectar source throughout growing season
Birds
Breeding season nectar source in western range (Apr-Aug)
Important nectar source during breeding season (Apr-Aug) and fall migration (Aug-Oct)
Seeds consumed during fall migration and winter staging in wetlands
Mammals
Cache seeds for winter food stores (Sep-Mar)