Loropetalum bonsai

Placement

Loropetalum chinense, Chinese fringe flower, is an evergreen to semi-evergreen shrub from East Asia with naturally arching branches, reaching 6.5–10 ft in the wild. Its oval leaves, dark green or purple, rough and paler underneath, line up in a single plane along the twigs, and the young shoots are hairy. In late winter or early spring, clusters of lightly fragrant flowers with narrow, strap-like petals open for two to three weeks: white in the species, pink in the purple-leaved forms. Usually grown outdoors, it needs full sun or bright partial shade. Sun deepens the color of purple-leaved cultivars such as ‘Ever Red’ or ‘Purple Diamond’, which have bright pink flowers. In regions with hot summers, shade during the hottest part of the day prevents leaf scorch. It can also spend part of the year indoors, in a bright, well-ventilated room with natural light.

Loropetalum is not hardy in a pot. It must be protected from freezing: in regions equivalent to USDA zone 8 or warmer it can stay outdoors year-round; elsewhere, overwinter it in a bright, frost-free place. Even in borderline zones, shelter it from cold winter winds. Stress and sudden temperature changes can cause some leaf drop, indoors or out.

Soil mix

Choose a well-draining mix that water passes through without pooling. An akadama-based mix with added pumice and lava rock works well. Loropetalum likes acidic soil: it does not tolerate alkalinity, which causes chlorosis, a yellowing of the leaves. So do not add lime or other alkaline materials to the mix. A mix that is too dense and holds water encourages root rot, one of the main risks for this species.

Watering

The root ball should stay evenly moist, with no long dry spells and no waterlogging. Water by observation, never on a fixed schedule: let the surface of the mix dry slightly, then water thoroughly so the water reaches the whole root system and runs out of the drainage holes. Overwatering leads to root rot; underwatering causes leaf drop and poor growth. Needs rise in hot weather and fall in winter, when the tree is kept cool.

In spring and summer, apply a balanced liquid fertilizer every two weeks; an organic slow-release fertilizer also works. Reduce and then stop feeding in late fall and winter, when growth slows.

Pruning

Loropetalum responds well to pruning and, over time, develops fine branching. Prune after flowering: let shoots extend several nodes, then cut them back to one or two leaves. Heavier pruning, to shorten a branch or change the outline, is done at the very start of spring or right after the main flowering. The plant also tolerates shearing.

A bacterial disease, olive knot, can cause swellings on twigs and trunk, followed by branch dieback. Choose a gall-free tree, cut infected twigs several inches below the gall, and disinfect tools between cuts with a 10% bleach solution. Powdery mildew and anthracnose are also reported.

Wiring

Wiring is generally well tolerated on young, flexible twigs. Older wood becomes brittle: bend it gradually, without forcing, and protect thick branches with damp raffia before bending them. Use wire about a third as thick as the branch, wound at roughly 45° and anchored with one or two turns. During the growing season, check it often, since a branch can grow around the wire within one to four months. Remove it by cutting it at every turn rather than unwinding it, and use a guy wire for branches that are too stiff.

Repotting

Repot in early spring, before new growth begins: every two years for a young tree, less often for a mature one. The roots are fibrous and tangle easily, so tease them apart patiently and prune them carefully, removing no more than about a third of the root mass. After repotting, water thoroughly and avoid fertilizer, heavy pruning and extreme conditions until growth resumes.

Loropetalum is propagated from semi-hardwood cuttings in summer: they root readily in warm, humid conditions with bottom heat. Seed is possible but rarely used, because seedlings do not come true to the cultivars. The species is fairly pest-resistant; still, watch for aphids, spider mites and whiteflies, especially in dry air. Regular misting and good air circulation help prevent them; if they appear, treat with insecticidal soap or horticultural oil. The loropetalum plant profile covers its garden care, cultivars and in-ground hardiness.