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Shrubby St. John's wort

Hypericum prolificum

Common names:
shrubby St. John's wort

Content Detail

Shrubby St. John’s wort is a low to medium-sized native shrub reaching 3 to 4 feet high. The bright yellow flowers with a profusion of yellow stamens look like fireworks. The exfoliating bark and attractive seed capsules add winter interest to the landscape. This species is native to the Chicago Region according to Swink and Wilhelm’s Plants of the Chicago Region, with updates made according to current research.

  • Family (English) Hypericum
  • Family (botanic) Hypericaceae
  • Tree or plant type Shrub
  • Foliage Deciduous (seasonally loses leaves)
  • Native locale Chicago area, Illinois, North America
  • Size range Small shrub (3-5 feet)
  • Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8
  • Soil preference Moist, well-drained soil
  • Tolerances Alkaline soil, clay soil, Dry sites, Occasional flooding
  • Season of interest early summer, midsummer, late summer
  • Flower color and fragrance Yellow
  • Shape or form Mounded, Multi-stemmed, Round
  • Growth rate Slow

Size & form: 

Shrubby St. John’s wort is a mounded, 3 to 4 feet high and wide shrub with stiff erect stems.

Native geographic location and habitat:

Native to the Eastern United States, including Illinois, Iowa, New Jersey, and Georgia. C-Value: 9 

Attracts birds, pollinators, or wildlife: 

Birds, butterflies, and bees are attracted to the flowers and fruit.

Bark color and texture: 

Young twigs are slender, gray, and ridged. Older stems exfoliate exposing a bronzy inner bark.

Leaf or needle arrangement, size, shape, and texture: 

Bright green leaves are opposite, linear to lanceolate, 4 inches long and 1/2 inch wide. Very short petioles with leaf-like bracts are at the base of the leaves.

Flower arrangement, shape, and size: 

Small, 3/4 to 1 inch wide yellow flowers with many showy stamens are borne in terminal or in stem axils in early summer.

Fruit, cone, nut, and seed descriptions: 

A three-chambered, upright, brown capsule that is persistent  throughout winter.

Plant care:

Shrubby St. John’s wort should be planted in full sun to part shade. Adaptable to most soil pH and even to heavy clay. Flowers on new wood, so prune in early spring. Can be short-lived in wet winters.

List of pests, diseases, and tolerances: 

None serious. Drought, clay, rabbit and deer resistant, tolerant of aerial salt spray.

Albury Purple Tutsan shrubby St. John’s wort (Hypericum androsaemum ‘Albury Purple’):

Low mounding, 2 to 3 feet high and wide, with rich velvety purple leaf tips, yellow flowers, and attractive dark red fruit capsules.

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