Kalm’s St. John’s-wort
Compact evergreen shrub reaching 60-90 cm tall with narrow blue-green leaves and bright yellow flowers blooming July-September. Prefers well-drained, sandy or rocky soils and full sun. Drought-tolerant once established. Excellent for rocky slopes, dunes, and dry gardens. Native to Great Lakes shorelines. Provides winter interest and supports pollinators.
Plant Details
Bloom Colour: Yellow
Bloom Time: Mid to Late-Summer
Sun Requirements: Sun to Part-Sun
Moisture: Dry to Moist-Drained
Phenology: Leaves emerge May. Yellow flowers appear July-August. Seed capsules develop September, persisting through winter. Semi-evergreen in protected sites.
Wildlife Value: Flowers attract native bees and beneficial insects; seeds eaten by small birds; dense growth provides cover
Habit Over Time: Creates a dense, mounded shrub with fine-textured foliage and upright stems. While it may slowly spread through root suckers, new stems emerge close to the parent plant, maintaining a tidy form. The multiple stems create a solid structure but allow some visibility through the plant at eye level. Provides good winter interest through persistent seed heads and stems.
Height: Short to Medium (2-3 feet)