Based on 1,240 research-grade iNaturalist flowering observations in Pennsylvania, White Snakeroot blooms mainly from September to October, peaking in September. It ranks #5 among wildflowers recorded in the state in our data.
Ageratina altissima
White Snakeroot in Pennsylvania by month
Bars show research-grade observations per month. They mix true seasonality with how often people are outdoors, so treat small numbers with caution.
Also in bloom in Pennsylvania in September
Common Jewelweed
Great Blue Lobelia
Wingstem
Flat-Topped Goldenrod
Bluestem Goldenrod
Asiatic dayflower
New England aster
Chicory
Places to look in Pennsylvania
National ForestAllegheny National Forest
State ParkPresque Isle State Park
Botanical GardenJenkins Arboretum
State ParkCherry Springs State Park
State ParkColton Point State Park
State ParkLeonard Harrison State Park
FAQ
When does White Snakeroot bloom in Pennsylvania?
Mainly September–October, with the most records in September.
How common is White Snakeroot in Pennsylvania?
It ranks #5 by number of iNaturalist flowering observations among wildflowers in Pennsylvania (1,240 records in our sample).