Hypericum x moserianum - St. John's wort

Hypericum x moserianum was obtained in the 1890s by Jean Jacques Moser, a horticulturist in Versailles. Less well-known than its variegated foliage cultivar 'Tricolor', it is, however, much hardier than the latter and has no specific requirements. Not very tall but clad in dense foliage that persists in winter in mild climates, it develops reddish-tinged and slightly arched stems that give it a lovely languid habit. It provides a long flowering period from July to October, in successive waves, in the form of cup-shaped flowers of a vibrant golden yellow punctuated with red stamens. A hardy, drought-resistant, ornamental, and floriferous plant, which will undoubtedly find its place in the garden.

Hypericum x moserianum is the result of a hybridisation between Hypericum patulum, a non-hardy and Chinese bush, and H. calycinum, a pretty much indestructible floriferous pest native to Turkey. It belongs to the Hypericaceae family. This relatively fast-growing shrub typically reaches a height of 50 to 60cm (20 to 24in) and a width of 60 to 70cm (24 to 7in), sometimes less depending on growing conditions. It has a bushy and rounded, rather sprawling habit, carried by flexible stems that are reddish to purplish in colour. They are adorned with entire, semi-evergreen leaves, which are evergreen in mild climates. The elongated leaves measure 5cm (2in), are pointed, leathery, and of a beautiful slightly bluish green. It practically flowers for four months of the year, from June-July to September-October, with a break during the hottest weeks. The flowers are produced abundantly at the tips of the branches. They are solitary or grouped in small clusters of 2 to 5. They measure 6cm (2in) in diameter and are composed of 5 rounded, bright golden yellow petals arranged in an open cup shape. The centre of the flower is occupied by a crown of protruding, long red anthers. This flowering is followed by the formation of a few conical fruits that are red and turn blue when ripe.

St. John's worts are appreciated for their very long flowering period and their real ease of cultivation in all types of soil and in all climates, even by the seaside. If you like yellow flowers, Hypericum x moserianum is ideal for a new garden, even if you are a gardening beginner. It excels in shrub borders and in flowering hedges, alongside the blue blooms of caryopteris, perovskia, nepeta, or perennial geraniums. Its yellow summer flowering will not compete with the more pastel spring blooms, while still shining under the harsh summer light. Summer-flowering red perennials such as Epilobium canum 'Western Hills' or shrubby salvias will create joyful scenes in a sunny garden. Perfectly hardy, it should be planted in full sun in cool regions, but in partial shade in hot climates to protect its foliage from scorching sunlight.