Jew’s mantle
These attractive deciduous shrubs have undeservedly fallen out of favour in nurseries and garden centres in recent years. They were once far more common in herbaceous borders and woodland garden settings than they are today. Recently visiting Trewithen Gardens near Probus I was struck at how spectacularly the double flowered Kerria japonica ‘Pleniflora’ was lighting up a dark shady corner in the garden there in late March. Time to revive production of these plants.
Kerria are completely hardy plants found in thickets and woodland in China and Japan. They are quite happy in full sun or in partial shade and are not too fussy about poor soils. However, this is a suckering spreading shrub which will develop more quickly in loose soils rather than compacted ones.
Kerria japonica does need its older stems pruning out periodically to encourage fresh new stems which will produce better flowers. An old clump with many old dead stems may need cutting back completely to ground level when dormant to rejuvenate the whole plant.
K. japonica has 4in long toothed green leaves on its arching individual shoots. The flowers appear in mid or late spring as solitary single or double yellow flowers. Clumps may grow to 4-6ft in height eventually with a smaller spread.
K. japonica ‘Pleniflora’ is very vigorous with large pompom-like double flowers. There is also an irregular creamy white margined variegated form called ‘Picta’.
