Great St. Johnswort
Hypericum ascyron
Last reviewed: June 2026
Light
full sun
Water
medium
Size
24"–48" H × 12"–24" W
Bloom
Jun, Jul, Aug
Native to
CT, IA, IL, IN and 13 more states
Pollinators
bees, butterflies, beetles
Great St. Johnswort is a tall native perennial that produces bright yellow flowers with prominent stamens from June through August. This robust plant forms upright clumps and thrives in full sun with moderate water needs.
In an HOA neighborhood
Great St. Johnswort is an HOA-friendly choice. Maintenance level: low. Tidiness: 3 out of 5.
Works well in: mid zone, foundation, backyard only.
- Tall height may appear unstructured in formal settings
- Winter dormancy leaves bare stems
Wildlife value
The cheerful yellow blooms attract bees, butterflies, and beetles throughout the summer months. This native plant provides important nectar resources during peak growing season.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Does Great St. Johnswort fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.