Hedera is a genus of 10 species of evergreen, woody-stemmed trailing or self-clinging climbers found in light woodland or on rocks and trees. The only limit to an Ivy’s suitability to bonsai cultivation is leaf-size, though this can be overcome to a degree by using bonsai cultivation techniques.
Ivy has alternate 3-5 lobed or entire leaves in a variety of colours. Ivy shows two distinct stages of growth. In the juvenile climbing stage, Ivy produces adventitious rootlets, lobed leaves and minute hairy young shoots. In the adult stage however, they produce entire broadly ovate leaves. When styling Ivy bonsai, it is important to try to keep the foliage consistent by repeatedly pinching out the adult foliage in order to keep only the juvenile lobed leaves.
In autumn, Ivy comes into flower which are sometimes followed by minute fruits.
BONSAI CULTIVATION NOTES
POSITION: Ideally partial shade though Ivy will cope with most situations.
FEEDING: Fortnightly through the growing season.
REPOTTING: As needed preferably in Spring though Ivy are resilient enough to be repotted at any time. Use standard soil mix.
PRUNING: Prune back hard repeatedly throughout the growing season to establish a central trunk, trim out old foliage unless required.
PROPAGATION: In summer, root semi-ripe cuttings of juvenile growth to obtain plants with a trailing habit; use adult growth to obtain plants with a more bushy, tree-like habit.
PESTS AND DISEASES: Red spider mites, scale insects, aphids and leafspot can be a problem.
STYLING: Informal upright forms and cascade forms in all sizes.