Ribes sanguineum Koja

Ribes sanguineum Koja is a selection of a floriferous and compact flowering currant bush whose blossoms open in a brighter red than other varieties. This hardy shrub has an upright habit, and its branches are adorned with deciduous green foliage with a hint of blackcurrant aroma, which is why it is also known as "False Blackcurrant". Thriving in most soils, including limestone, and preferring moist to moderately dry conditions, it grows in full sun or partial shade and is one of the easiest plants to grow successfully. It can be planted in a small hedge or a mixed border.

Formerly classified in the Saxifragaceae family, Ribes is now the only member of the Grossulariaceae family, and it comprises over 100 species. Ribes sanguineum is the most floriferous and ornamental species in the genus. Native to the United States, where it grows from northern California to British Columbia, in Pine and Thuja forests at elevations between 600 and 1800 metres, it was discovered in 1793 and introduced into cultivation in 1826 by David Douglas. It forms shrubs that reach 2 to 3 metres in height, with carmine pink flowers in pendulous clusters measuring 5 to 10 cm in length, which then develop into chalky black round fruits. Several cultivars are available on the market, including the ancestral 'Atrorubens' dating back to 1837 and more recently, Koja.
The Koja flowering currant bush has a more compact habit than the species, typically reaching 1.50 metres in height (up to 2 metres depending on conditions) and 1 metre in width. It is a medium-growing shrub, about 20 cm per year. It has a distinctly upright habit, producing relatively slender branches that are a beautiful shade of more or less mahogany brown, practically erect. From April, leaves and flowers appear more or less at the same time, marking the beginning of spring in the garden. The round leaves with 5 shallow lobes measure from 5 to 10 cm in length, starting light green and becoming darker over time.
The inflorescences consist of 8 to 10 cm long clusters of about twenty small flowers with five bright red petals, enhanced by a whitish centre. The clusters have a weeping habit and their colour pleasantly contrasts with the young foliage, creating a charming scene. Distributed along the length of the branches, the flowers bloom for 3 to 4 weeks, until May. They then develop into small, round, black fruits, measuring 7 to 8 mm in diameter. In autumn, the deciduous shrub sheds its foliage to better withstand cold temperatures, down to around -20°C.

The Koja flowering currant bush is one of those plants that beginners love, alongside Forsythias and Weigelas, because they are so easy to grow. You can plant it in a small informal hedge, alongside Philadelphus Bouquet Blanc, a Mock Orange with pure white flowers that bloom just after the Koja, in May and June. If you don't mind thorns, you can also add a Rosa glauca, a superb wild rose with bluish foliage that provides the perfect backdrop in June-July for the simple, vibrant pink flowers illuminated by a golden centre, that produces decorative red and shiny hips from autumn until winter. And for summer and autumn, nothing beats a Hibiscus syriacus to enjoy stunning single or double flowers in white, pink, red, purple, blue, or even bicoloured, as the choice of varieties is vast.