Stewartia trees are part of the Theaceae family alongside Camellia and have beautiful flowers; usually white with a mass of golden stamens that bloom in early summer and the flowers are bisexual. They are renowned for their decorative bark that flakes with age and leaves a mottled pattern on the trunk.
They have a very graceful form with dark green leaves that turn yellow through to brown in autumn and they are deciduous so winter is a great time to show a Stewartia as a bonsai to see the full glory of the trunk and branches.
The three main types of Stewartia used in bonsai are:-
- Stewartia monadelpha (Mountain Stewartia with violet anthers and a shiney copper bark)
- Stewartia pseudo camellia (Japanese Stewartia with glabrous shoots and yellow to red autumn colour)
- Stewartia pteropetiolata var. koreana (Korean Stewartia which is semi evergreen and less hardy)
They prefer an acid soil that is rich in organic matter that is well drained but does hold moisture and roots should be shaded in hot sun. Water with lime free water, as this species is not tolerant of a low pH and feed with ericaceous fertilizer.
They respond well to pruning but can suffer branch die back if left exposed in winter so protection from hard frosts is essential. Prune little and often rather than remove large quantities at once as this improved back budding with regular pruning and retains a more even shape and canopy. The bark is softer so avoid wiring unless necessary and ensure to check this often to avoid wire marks.
They can be propagated from seed, stem cuttings and air layering and the timing for this is around May to June.
In terms of styles they are good as an informal upright, group plantings and twin trunk or clump styles work well.
Other species of Stewartia within this genus include:-
- Stewartia malacodendron (Stamens purple and solitary flowers)
- Stewartia ovate (Large bushy shrub)
- Stewartia serrate (Flower petals stained red and cup shaped and earlier to flower)
- Stewartia sinensis (Crimson autumn colour)
Here are a few more images of Stewartia as bonsai in the gallery below.