Forsythia is a genus of 7 species of deciduous, occasionally semi-evergreen shrubs found in open woodland in E. Asia. They bear opposite, simple, toothed or entire leaves.
Forsythia are best known for their buttercup yellow flowers that form on bare branches in Spring. Flower buds emerge at the side of the leaves; it also produces new shoots in areas where there have been flowers.
All Forsythia species are suitable for use as bonsai; they are however quite coarse growing and are primarily grown for their flower display in Spring.
BONSAI CULTIVATION NOTES
POSITION: Full sun or light dappled shade. Fully hardy to -10°C.
FEEDING: Every two weeks throughout the growing season.
REPOTTING: Every two or three years in Spring after flowering.
PRUNING: After flowering, prune back branches hard and continue to prune out growth until mid-Summer after which the following Spring’s flower buds will be produced and only minimal pruning should be carried out.
PROPAGATION: Root greenwood cuttings in late Spring or early Summer. Root semi-ripe cuttings in Summer. By division in Winter and early Spring.
PESTS AND DISEASES: Forsythia gall can affect some plants; birds may eat flower buds in early Spring.
STYLING: Informal upright forms and cascades in all sizes.
Deadwood is very weak and prone to rotting if not protected. Wire branches when young as they become brittle with age.
