Hypericum, a genus of plants in the Hypericaceae family, includes 76 species ranging from herbaceous perennials to woody deciduous shrubs and broadleaved evergreens. Growing conditions and sun requirements vary depending on the type of hypericum. Plant hypericum shrubs along border areas or in shrub beds. Herbaceous hypericum species add sunny yellow colour to the perennial garden bed.
Sunlight and Shade
The first step to picking the best spot for a hypericum plant involves matching the sun requirements of the plant to the available sun in the garden. The definitions full sun, part sun, part shade and shade indicate the hours of sunlight an area gets. Full shade means the spot gets two hours or less of sun each day while full sun indicates at least six hours of direct sunlight. Part shade indicates two to four hours while part sun means four to six hours.
Herbaceous perennial hypericum plants grow best in full sun or part sun and tolerate part shade. Full shade does not provide a suitable growing environment. Plant perennial hypericum in the garden to add a splash of yellow to flower beds. Herbalists grow hypericum perforatum, common St. John's wort, for its medicinal properties. The plants grow 1 to 3 feet tall and flower between June and August. The herbaceous hypericum variety Hypericum pyramidatum, or great St. John's wort, grows 2 to 5 feet tall.
Deciduous and broadleaved evergreen shrubs in the hypericum genus grow best in full sun or part sun. Many tolerate partial shade well but suffer in full shade conditions. The deciduous Hypericum prolificum, or shrubby St. John's wort, does best in full sun, while the deciduous Hypericum frondosum "Sunburst" grows in full sun or part shade. The broadleaved evergreen Hypericum kalmianum, or Kalm's St. John's wort, thrives in full sun and part shade.
Hypericum for Full Shade
Rose of Sharon (Hypericum calycinum) grows in a range of light conditions from full sun to full shade. This woody evergreen shrub grows 1 to 2 feet tall with a spread of 3 feet. Use this low-growing, shade-tolerant hypericum as an evergreen ground cover under landscape shrubs and along border areas. The yellow flowers begin blooming in summer, usually around June, and continue to bloom into fall. Rose of Sharon tolerates some drought conditions and thrives in soil with good drainage.
- USDA Natural Resource Conservation Service: Classification for Kingdom Plantae Down to Genus Hypericum L.
- UConn Plant Database: Hypericum Prolificum
- Missouri Botanical Garden: Hypericum Kalmianum "Ames"
- USDA Forest Service Weed of the Week: Common St. John's Wort
- Plants for a Future Database: Rose of Sharon
- University of Illinois Extension: Sunlight