Hypericum densiflorum Buttercup - St. John's wort

Hypericum densiflorum 'Buttercup' is, like the majority of St. John's wort, the archetype of an easy-to-care-for, generous plant, that is comfortable everywhere. This one is an all-terrain bush, not very tall, aromatic in all its parts, with dense and particularly fine foliage of a beautiful bluish green that turns yellow in autumn before falling. It provides a long flowering period from July to October, in the form of small bright golden yellow cups. It will thrive in all soils that are not too dry, in the company of other easy-to-care-for wild plants.

'Buttercup' is derived from Hypericum androsaemume. This medicinal and aromatic plant is native to southwestern Europe, particularly from a region called Anatolia, located at the western end of Asia. In nature, this undershrub grows in wet meadows, at the edge of ponds, in cool undergrowth, not far from watercourses. It belongs to the Hypericaceae family.

The 'Buttercup' cultivar is distinguished by its uninterrupted summer flowering in moist soil. This fairly fast-growing bush generally does not exceed 80cm (32in) in height and 1m (3ft) in width, but sometimes much more depending on growing conditions. It has a dense and rounded habit, rather spreading, carried by red to cinnamon-coloured stems, all arising from the stump. They are adorned with elongated, pointed, long, entire and narrow, leathery leaves, 5 to 10cm (2 to 4in) long. The deciduous foliage is a beautiful dark green with a slightly bluish underside, taking on a beautiful yellow colour in October highlighted by the cinnamon-coloured branches. It blooms practically four months of the year, from June-July to September-October, with possibly an interruption during the hottest weeks if the soil is dry. The flowers, produced abundantly in racemes of 5 to 11 flowers, 2.5 to 3.5cm (1in) in diameter, consist of 5 rounded, golden yellow petals arranged in an open cup. The centre of the flower is occupied by a crown of prominent, fairly long stamens. This flowering is followed by the formation of a few conical fruits that are red, then blue-black when ripe.

St. John's wort is appreciated for its long flowering period and its ease of cultivation in all soils and under all climates, even by the seaside. If you like yellow flowers, 'Buttercup' is ideal for a new garden, even for novice gardeners. It excels in low shrub beds or perennial beds, but also in undergrowth, at the edge of a grove. For example, it can be combined with dwarf buddleias, a Morning Mist rose, shrubby lavatera, weigelas (in moist soil), or Rhaphiolepis (in dry soil). Its yellow flowering will not compete with the more pastel spring flowering. Perfectly hardy, it should be planted in full sun in cool climates, but in partial shade in hot climates to protect its foliage from scorching sun.