Radermachera sinica aka China Doll Plant

Radermachera sinica is an evergreen tree in the Bignoniaceae family. Its common names include China doll and Asian bell tree. Its native range runs from the eastern Himalaya to southern China. It also includes northern Indo-China and Taiwan. The tree comes from a wet tropical climate. Gardeners grow it indoors where winters are too cold. It also suits warm greenhouses and conservatories.

The tree has a bushy shape and glossy green leaves. Each leaf divides into many smaller leaflets. These leaves stay on the plant through the year. The RHS gives a cultivated height of 5–8 feet [1.5–2.5 metres]. Its listed spread is 3–5 feet [1–1.5 metres]. Yet its profile says houseplants seldom exceed 6.6 feet [2 metres]. Wild trees can reach 98 feet [30 metres]. The RHS gives five to ten years to reach mature size. Pinching young shoot tips helps the plant form more branches. Cutting back older plants helps keep their size in check.

Chicago Botanic Garden lists yellow and white flowers in May and June. Missouri Botanical Garden describes the flowers as showy. The evergreen leaves also give the plant interest in winter. In warm regions, it can stand alone as a specimen tree. It can also serve as a small shade tree. A sheltered spot suits this landscape use. In colder regions, containers can spend summer on patios or porches. They need to return indoors for winter. Chicago lists USDA zones 10–12, while the RHS gives H1B.

For indoor growth, the RHS calls for warmth and bright, indirect light. Outdoor listings allow full sun or partial shade. Use peat-free compost with sand or perlite to improve drainage. The soil should stay moist but drain well. The RHS lists loam and a neutral soil pH. Chicago gives a moderate watering need. Changes in location or growing conditions can cause leaf loss. Keeping the growing conditions steady helps avoid this problem. Semi-ripe cuttings offer a way to raise new plants.

Missouri Botanical Garden reports no major pest or disease problems. Indoor plants can still attract aphids and spider mites. The RHS also lists mealybugs and scale insects as possible pests. Soil that stays too wet can lead to root rot. The supplied sources give no information on edible parts or toxicity.