Japanese camellia bonsai

Placement

Japanese camellia is grown outdoors. During the growing season, choose a mild, well-ventilated spot in partial shade: morning sun and afternoon shade suit it best, with protection at the height of summer. Shelter it from cold winds. Light, dappled shade, as under a tree, suits it very well.

Winter needs care. The tree is not fully hardy in a pot, and its flower buds, formed from late the previous summer, suffer in the cold: a harsh winter turns them brown and makes them drop before opening. Keep it somewhere cool but frost-free, such as a cold frame. During cold snaps, wrap the pot in fleece or bubble wrap to protect the roots. Above all, avoid early morning sun after a frosty night: it is the leading cause of browned flowers and buds.

Several problems threaten this camellia. Tea scale leaves yellow blotches on the upper leaf surfaces; other scales, flat and light brown with an elongated white egg sac on the leaf undersides, produce honeydew on which sooty mold, a black coating, develops. Treatments target the young mobile crawlers, with horticultural oil or insecticidal soap; afterward, gently wipe the leaves. Black vine weevil attacks the roots: inspect the mix at every repotting. As for diseases, petal blight marks the flowers with brown spots: remove and pick up affected flowers at once. Leaf gall swells young shoots and leaves into thick, fleshy growths: cut the galls off while they are young. Perfect drainage limits root rot, which is hard to stop once established, and avoiding wounds limits cankers. Do not mist open flowers, as water spoils them. The same symptom, such as yellowing, can have several causes.

Soil mix

Camellia is an acid-loving plant. Use a lime-free, well-draining mix, such as kanuma. An alkaline mix causes yellowing between the leaf veins, a sign that the plant can no longer take up iron and manganese, and it can eventually kill the tree.

Watering

The root ball must stay constantly moist and never dry out completely. Do not water by the clock: check the pot every day and water thoroughly as soon as the surface starts to dry, until water runs out of the bottom. Needs rise sharply in summer. Late summer matters most, because that is when next year’s buds form: dry mix at that time, or in early spring, makes them abort and drop. In winter, kept cool, the root ball only needs to stay slightly moist.

Camellia dislikes hard water: use rainwater, or water that is neutral or slightly acidic. In hard-water areas, prolonged use of tap water eventually yellows the foliage.

Fertilizer: use a fertilizer for acid-loving plants (azaleas, hydrangeas, camellias). Apply it weekly in liquid form, or every four weeks as a solid organic feed, during the growing season. Never feed while the tree is flowering, and stop by midsummer: excessive or late feeding makes the buds drop.

Pruning

Pruning is done in spring, right after flowering, and follows the rhythm of the flowers.

• After flowering: remove spent flowers, then cut new shoots back to two or three leaves. This pruning encourages back-budding on older wood and makes the branching denser.
• Pinching: pinch the tips of young shoots in spring, then stop from midsummer to early fall so you do not remove the shoots carrying the future buds.
• Hard pruning: camellia does not take it well, and severe pruning delays flowering for several years. Build the silhouette gradually.

Styles: the most common are informal upright, with a single trunk or several trunks, and cascade. Cultivars with small leaves and small flowers make the best-proportioned bonsai.

Propagation: sow seed in spring after soaking it for a day in warm water, though seedlings grow very slowly. Semi-hardwood cuttings, taken in midsummer, are slow and sometimes difficult to root; air layering is done during the growing season.

Wiring

Camellia is best wired in winter. Its bark is very tender and wire marks stay visible for a long time: wrap the wire in paper or masking tape, or protect the branch with raffia. Wire works on branches no thicker than a pencil. Choose wire about one third the thickness of the branch, wound at roughly 45°.

Check it regularly, because the branches are brittle and mark quickly. Remove it before it bites in, cutting it at every turn rather than unwinding it. For sturdier branches, use a guy wire instead, which avoids coiling wire around the bark.

Repotting

Repot every two or three years, in early spring, after flowering. Prune the roots only lightly, removing at most about a quarter of the root mass. Cover the drainage holes with mesh, add a drainage layer and then the acidic mix, and work out air pockets with a chopstick. Water thoroughly afterward, then keep the tree sheltered from extremes of heat, cold and wind while it recovers, with no hard pruning or fertilizer right away.

The Japanese camellia page covers its care in the garden and in large containers.