Culture
Easily grown in average, medium, well-drained soil in full sun to part shade. Tolerates wide range of soils. Thrives on sandy soils in full sun. Evergreen in warm winter climates, but probably should be cut back in early spring. Usually dies to the ground in cold winter climates. Not reliably winter hardy in USDA Zone 5, however, and plant should be grown therein in a protected location with a winter mulch.
Noteworthy Characteristics
Hypericum × moserianum is a cultivated hybrid of St. John's wort resulting from a cross between H. calycinum and H. patulum. Mature plants have gently arching stems and a rounded habit, reaching 2-3' tall with an equal spread. The golden yellow flowers can reach 2" wide and bloom from mid-summer into early fall.
Genus name comes from the Greek words hyper meaning "above" and eikon meaning "picture" in reference to the practice of hanging flowers from this genus above images, pictures or windows.
Plants of the genus Hypericum (some species therein have been used since ancient times in the treatment of wounds) were apparently gathered and burned to ward off evil spirits on the eve of St. John's Day, thus giving rise to the genus common name of St. John's wort.
Hypericum × moserianum 'Tricolor' This St. John's wort hybrid cultivar is a small, mounded shrub with reddish, arching stems and variegated, oval to oblong, rosy green leaves (to 2" long) which are edged with white. In warm winter climates, this shrub typically grows 2-3' tall. It grows somewhat smaller (12-15" tall) in cold winter climates where it basically dies back each year in the manner of an herbaceous perennial. Features 5-petaled, buttercup-like, yellow flowers (1.5" diameter) having numerous, bushy stamens. Flowers are borne singly or in clusters and appear from mid-summer to fall.
Problems
No serious insect or disease problems.
Uses
Best in borders or rock gardens. Smaller plants in cold winter climates make effective edgers. Shrubs in warmer climates can be used as informal hedges.