Spiraea ‘Genpei’ is a popular, beautifully flowering deciduous shrub. It also goes by the – older, but still common – name ‘Shirobana’. This slow-growing (10-15cm p.a.) dwarf variety, which will reach a final height of no more than 70-100cm, produces corymbs of dark pink, white and rose flowers – all on a single shrub. Spiraea ‘Genpei’ is an outstanding, unique ornamental plant which will add plenty of interest to your garden. Spiraea varieties are an excellent addition to borders and shrubberies, but not suitable as a screening hedge due to their height and deciduous nature. The flowers will brighten up the garden from mid to late summer and adorn the branches simultaneously with the bright green finely toothed foliage.
And if you wish to support – endangered – pollinators, spiraea ‘Genpei’ makes a very useful shrub, attracting bees, bumblebees, butterflies and other useful insects. The shape and flowers of this shrub make it a popular choice among landscapers, which is why it is often seen in public areas, for example in parks. Deadheading the flowers regularly will enhance this shrub’s ornamental value, as the flowers tend to become unsightly as they fade. Pruning is highly recommended to maintain the shrub’s lovely shape and to further improve its appearance.
Spring pruning will encourage new growth and flowering will be much more rewarding. Cutbacks of up to two thirds of previous year’s growth are permissible. Spiraea ‘Genpei’ can adapt to most soils, but will do best in a nutritious, moist soil that is slightly acidic. The best sites for spiraea ‘Genpei’ are situated in full sun to partial shade. Cold winters are no concern: spiraea ‘Genpei’ can withstand temperatures as low as -35C. On the whole, spiraea ‘Genpei’ (or ‘Shirobana’) is easy to grow and not particularly demanding.