This family of herbaceous perennials and mostly evergreen shrubs has some easy-to-grow varieties. Its bright yellow, cup-shapedappear in late summer and early autumn. Some varieties bear simultaneous fruits.
Suitable site and soil. St John’s wort will grow in almost all well-drained soils and, though many varieties will tolerate shade, flowering is best in full sun.
Cultivation and care.the larger shrubs by about a third in spring, using shears, and cut out any old or damaged . H. calycinum should be clipped back hard, it down almost to ground level.
Propagation. Takewith a heel in summer of shrubs, in spring of herbaceous plants, and grow on in a cold frame. Transplant to flowering positions the following spring.
Recommended varieties. H. ‘Hidcote’ is one of the most spectacular and popular of the shrubs. It has large abundant goldenfrom midsummer to late autumn (height 1.5m – 5ft). H. x moseranum has arching reddish and the flowers have red anthers. H. x m. ‘Tricolor’ is a dwarf shrub with variegated pink, white and green . H. inodonim has pale yellow flowers and fruits. The form ‘Elstead’ has brilliant salmon-red fruits at the same time as the flowers. H. calycinum (rose of Sharon) is a small shrub (30-45cm – 12-18in) which grows in dry and shady places. H. olympicum is a good rock garden plant with grey-green leaves.
Pests and diseases. Rust may appear as spots on the leaves.
H. x inodorum and its form ‘Elstead’ both have brilliant red or pink fruits which appear at the same time as their golden flowers. The berrying branches look lovely and last well in flower.