Gardening Questions And Answers
Problems. Plants sometimes become infected with kerria twig and leaf blight, a fungal disease caused by Blumeriella kerriae, which produces leaf spots and stem lesions, and may result in severe defoliation. Spots typically coalesce (merge) and cause the leaves to turn yellow to brown and then drop from the plant.
Want earlier blooms? In the winter, the long green now leafless stems look graceful and exotic in the garden or they can be cut and used indoors in winter flower arrangements. Japanese Kerria does best in part sun, part shade. In full sun, the flowers can fade more quickly, but the shrub will survive nicely.
Kerria is not particular about lighting and grows well in full sun or full shade. It performs best in moist, rich soil but will tolerate poorly drained soil as well as sandy soil and drought. Kerria spreads slowly to form a clump. Keep this spreading habit in mind when selecting a planting location.
It is somewhat unique among flowering shrubs that kerria blooms profusely in partial shade. The flowers are bright golden yellow with five petals – very similar to an old-fashioned rose. It has a bloom time that begins in late March to mid-April in Upstate South Carolina, and flowering lasts for a couple of weeks.
Japanese Kerria Care Basically, just water Japanese Kerria regularly, but avoid over-watering. The plant is fairly drought-tolerant and doesn’t do well in soggy soil. Seriously overgrown shrubs can be rejuvenated by cutting the plant to the ground, which improves blooming and creates a fuller, healthier plant.
Cultural Requirements: Kerria japonica is best in our region with afternoon shade, but is suitable for full sun in cooler climates; well drained acidic to neutral oils with consistent moisture and organic matter are needed in hotter climates; periodic pruning is needed to maintain a presentable appearance.