To the genus Kerria belongs only the japonica species, native to Asia; it is a medium-sized shrub, which reaches 200-250 cm in height, with a rounded shape.
The stems of kerria japonica are thin, arched, poorly branched, each plant produces numerous basal shoots, which tend to develop fairly quickly.
The foliage is deciduous, small, dark green in color; the leaves have a serrated or notched margin.
In spring, from March to May, it produces countless small golden yellow, five-petal flowers, similar to small yellow roses.
Numerous cultivars can be found on the market, the most common being K. j. pleniflora, with double flowers, similar to small pompoms; there are also white-flowered cultivars, or with delicately variegated foliage.
In general, spring flowering is very abundant, followed by a second flowering in late summer, with the production of a few scattered buds. Plant very widespread in the gardens of the past, especially in the case of the Pleniflora variety, now it seems to be enjoying a second youth, even if in the last few years the single-flowered varieties are particularly spreading.
Japan's kerrie tolerate any exposure, from full shade to full sun. Generally, the plants placed in total shade tend to produce few flowers, while the buds of the specimens in full sun are short-lived and tend to whiten with exposure to sunlight.
There kerria japonica it is a shrub definitely suitable for partial shade, where its flowering is abundant and long lasting and the development of the plant quite vigorous.
These plants bloom on the branches of the previous year, it is therefore recommended to prune after spring flowering.