Scientific Name: Wisteria sinensis
Wisteria do not conform to normal bonsai styling; the styling is to show off their highly scented flowers up to 30 cm long. The colour is determined by the variety and is a choice of purple, blue or white. Flowering is in late spring or summer and is followed by leaf foliage. The two species most selected for bonsai are:
Japanese Wisteria (W. sinensis) or Chinese Wisteria (W. chinensis).
Encouraging Wisteria to flower:
Wisteria planted in a pot or tray are more reluctant to flower than when planted in the ground. Wisteria will not flower until they reach a certain age; this can take from about
6 to 10 years. Bonsai wisteria should be pruned in the same way as you would prune it in the ground. Prune back all shoots (that do not conform to the structure of the tree) to 5 or 6 inches of the main trunk or branch leaving only 4 to 6 leaves on each shoot. This should carried out after flowering and can be repeated 2 to 3 times until Autumn. In the
middle of winter, reduce the spurs again to 3 or 4 inches, leaving only 2 to 3 buds.
As well as these repeated prunings a hard pruning in mid-winter reduced leaf production and encourages flowering and also encourages dense foliage and flowering.
Full sun or partial shade but should be protected from the wind as when in bloom they become top heavy. They stress and tend to dry out from strong winds, therefore the watering is very important for it’s survival. they should be kept moist at all times, but not
to wet as they are prone to root rot.
Always repot just after flowering in spring every 2 to 3 years as the root system has a very prolific growth. Repot in a basic soil mix, although I have achieve my best results by
using one part debco bonsai mix to one part akadama. Use a fairly deep pot as root growth is very rapid, but bearing in mind the flowering will be affected for the first year after repotting, but will increase the following year.
Wisteria require large quantities of water compared to most other bonsai species and require heavy watering to keep them continually moist. In order to assist with this a good free draining mix is very important as recommended above.
Many people recommend a low-nitrogen fertilizer every 2 weeks after flowering is ended
but my personal choice is 15 mls of maxicrop plus 15 mls of nitrosol to 2 litres of water.
One coffee mug of this mix applied after flowering once weekly until the end of March.
Then continue with normal watering until spring.
Pests and Diseases:
Aphids, Leafspot and brown scale are the main offenders.
Wisteria can be styled in informal upright, slanting or cascade in medium or large sized bonsai as this exhibits the best forms which allow their flowers to cascade to their full length and potential.
"Bonsai is the creation of living art and the blending of elements"