Hypericum calycinum (St. Johns Wort)

Hypericum calycinum (St. John’s Wort) is a small, semi-evergreen shrub with screaming bright yellow flowers, 3 in. wide (7 cm), for weeks from mid-summer to mid-fall. Each rose-like flower presents 5 petals surrounding a prominent tuft of bushy stamens and reddish anthers. Borne solitary or in clusters of 2-3 flowers, they appear in such quantities that they literally cover the foliage.

Hypericum calycinum (St. John's Wort) is a small, semi-evergreen shrub with screaming bright yellow flowers, 3 in. wide (7 cm), for weeks from mid-summer to mid-fall. Each rose-like flower presents 5 petals surrounding a prominent tuft of bushy stamens and reddish anthers. Borne solitary or in clusters of 2-3 flowers, they appear in such quantities that they literally cover the foliage. Arranged along procumbent stems, the oval leaves emerge chartreuse-bronzed but quickly turn to medium green, dark green, then blue-green – contrasting against the yellow flowers. A popular groundcover thanks to its lush dark green to bluish-green foliage and its golden flowers. Evergreen in warm winter climates.

  • Grows up to 12-18 in. tall (30-45 cm) and 18-24 in. wide (45-60 cm). Spreads rapidly by underground stems. May invade other plantings unless confined.
  • A full sun to part shade lover, this plant is easily grown in medium moisture, well-drained soils. Tolerates a wide range of soils but thrives in sandy soils. Best flower production occurs in full sun. Drought tolerant once established.
  • Low maintenance, this plant is also generally pest and disease free. Deer resistant.
  • Perfect for rock gardens, border fronts, naturalized plantings or massed as a ground cover. Great on banks and slopes for erosion control or under trees where it competes well with shallow tree roots.
  • Clip or mow plants in late winter or early spring every 2-3 years to renew and promote new growth.
  • Native to Southern Europe, Southwestern Asia

Requirements

Hardiness 5
– 9

Heat Zones 4
– 9

Climate Zones 2, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Shrubs
Plant Family Hypericum – St John's Wort
Exposure Full Sun, Partial Sun
Season of Interest Summer (Mid,Late)Fall
Height 1'
– 2'
(30cm
– 60cm)
Spread 1'
– 2'
(30cm
– 60cm)
Spacing 18″ (45cm)
Water Needs Average
Maintenance Low
Soil Type Chalk, Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Well-Drained
Characteristics Showy, Semi-Evergreen
Tolerance Drought, Dry Soil
Garden Uses Banks and Slopes, Beds and Borders, Ground Covers
Garden Styles Gravel and Rock Garden, Informal and Cottage, Prairie and Meadow