Hypericum kalmianum Blue Velvet - St. John's wort

Hypericum kalmianum 'Blue Velvet' revisits the palette of St. John's wort bushes that we are used to seeing in gardens, while keeping the more than accommodating qualities that characterises these kings of summer. Interesting even before flowering, it bears narrow, willow-like foliage, with a soothing bluish glow. This bluish tone perfectly complements its golden-yellow small flowers adorned with a superb pompom of stamens. They bloom all summer and produce red berries that persist on the branches until late in the season. In autumn, its leaves often take on beautiful colours under the effect of the cold. There are a thousand good reasons to adopt this fully hardy bush, resistant to drought and almost foolproof!

'Blue Velvet' is a recent horticultural acquisition from Hypericum kalmianum, a botanical species native to North America. 'Blue Velvet' was developed in Nebraska, in a region of the U.S.A renowned for its difficult climate. This small bush belongs to the Hypericaceae family. Growing quite quickly, it generally does not exceed 80cm (32in) in height with 1.2m (4ft) in width, depending on growing conditions. It shows a dense and rounded habit, which is slightly irregular, carried by quadrangular arched stems. They are garnished with long, entire and narrow leaves, most often semi-evergreen. The leaves are elongated, pointed, and 4 to 6cm (2in) long. They are a beautiful bluish green on top, silver blue underneath, becoming orange red in the autumn. It flowers from July to September, for 3 months, depending on the climate. The abundant flowers appear in bouquets of 5 to 7 flowers, 3 to 4cm (1 to 2in) in diameter. They are composed of 5 rounded golden to orange petals arranged in an open cup. The centre of the flower is occupied by a particularly decorative bouquet of prominent stamens. This flowering is followed by the formation of small conical red fruits, which turn brown when ripe.

St. John's wort is appreciated for its long flowering period and ease of cultivation in all soils and under all our climates, even by the sea and even in the shade. 'Blue Velvet' is an ideal small bush to plant in a new garden, even for novice gardeners. It excels in all areas of the garden, whether they are sunny or shaded and impoverished by tree roots. It only requires well-drained soil to thrive in beds. In light undergrowth, it can be planted with snowberries, and Lonicera nitida, which will cover the soil with a dense and ornamental vegetation. In the sun, plant it with shrubby lavatera, Berberis thunbergii 'Atropurpurea Nana', blue perennial geraniums, Alchemilla mollis, or a dwarf conifer with silver-blue foliage like Picea pungens Glauca 'Globosa'. Its yellow flowering will not compete with more pastel spring flowering. Perfectly hardy, plant in full sun in cool regions, and semi-shade in hot climates. Protect its foliage from scorching sunlight.