Propagation Methods and Planting Techniques for Kerria japonica

Growth Habits of Kerria japonica

Kerria japonica is a deciduous shrub native to China from North China to South China, distributed in Anhui, Zhejiang, Jiangxi, Fujian, Henan, Hunan, Hubei, Guangdong, Gansu, Shaanxi, Sichuan, Yunnan, Guizhou, Beijing, Tianjin and other places. It prefers warm, humid and semi-shaded environments, has poor cold tolerance, and is not demanding about soil, growing best in fertile, loose sandy loam.

Propagation Methods for Kerria japonica

1. Division: carried out in early spring and late autumn, using a knife or spade to directly split new plants each with 1 to 2 branches from the mother plant in the soil and take them out for transplanting; the mother plant left in the soil is divided again the following year.

2. Cuttage: for Kerria japonica, hardwood cuttings in March use non-sprouted one-year-old branches, and around June softwood cuttings are used, in brown soil, matured soil or sandy soil; if cuttings are placed in the open field, shade is needed to prevent drying out.

3. Sowing: the sowing propagation method is only used when mass-propagating the single-petaled original species; after the seeds are harvested, they need to be stratified in sand at 5°C for 1 to 2 months, sown the following spring, covered with fine soil and then with grass after sowing, and shaded with a frame after seedlings emerge.

Planting Techniques for Kerria japonica

1. Soil: the planting site for Kerria japonica should be chosen as a warm, humid, soft soil, well-drained, non-alkaline soil.

2. Transplanting: the transplanting site for Kerria japonica is applied with base fertilizer, compost, barnyard manure, decomposed human feces and urine, etc., mixed evenly, leveled, and transplanted in the open field or potted before spring sprouting or in October.

3. Water and fertilizer: Kerria japonica generally does not need frequent watering; potted plants should be watered with cake fertilizer water in the afternoon, and should not be watered too much. In summer, more watering is needed, and 1 to 2 times of liquid fertilizer should be applied as appropriate during the entire growth period depending on the vigor of the seedlings.

4. Pruning: when dieback is found on Kerria japonica, immediately cut off the dead branches, otherwise it will spread to the roots and cause the death of the whole plant. After flowering, leave 50 cm of height and cut off the upper branches to encourage underground buds to sprout.

5. Repotting: in cold regions, potted Kerria japonica is repotted about once every 3 years, combined with root trimming, division, and renewal of old and weak branches.