An early flowering spring shrub, native to China and extensively cultivated in Japan for its blooms of golden-yellow flowers, is a herald of spring. It is now grown widely worldwide in temperate zones, where its weeping form and flashes of golden colours make it a focal point of many an urban garden.
Forsythia Bonsai make excellent spring-flowering specimens of small and medium-sized bonsai. It is usually easy to grow as straggly informal or clump style bonsai.
Position: Prefers a full sun position, although it can grow in semi-shade. It will develop a good crop of flowers in a sunny position and have excellent Autumn colour. While it is a frost-hardy species as bonsai, it likes to be protected in a greenhouse from freezing pots and excessive rain.
Watering: Water thoroughly early in the morning to ensure that the bonsai has the water when needed and is not sitting in water overnight. When watering, just water the pot as watering the crown will likely damage any flowers.
Feeding: Feed with organic fertiliser, every two weeks with liquid nutrition or every two months if using a pelletised version. Lime helps set the fruit and balance out any excessive acidity of the organic feed.
Repotting: Repotting every year helps keep your clumps in control. Best repot in Autumn after flowering and fruiting. Use a free-draining soil of loam, sharp sand and well-mulched bark in equal parts. Alternatively, you can use Akadama and pumice in a ratio of 2:1 by volume.
Pruning: Prune back current year’s growth to leave three lateral shoots or three active nodes. Structural pruning of thick branches to be left until late winter early spring. Remember that any winter pruning will reduce next seasons flowering buds. To maintain a healthy trunk system, you will need to remove any suckers as they appear.
Wiring: Wire in Autumn, and remove the wire before bud break in spring. Leaving wire on more prolonged may result in scaring off the branch.
Propagate: Forsythia propagate quickly, and you can be multiplied using use air or soil layering or soil, semi-hardwood and hardwood cuttings. Semi-hardwood cutting in spring is perhaps the most successful, but Autumn Hardwood cuttings are just as successful.