Water regularly, especially during dry periods, ensuring the soil is consistently moist but not waterlogged. Reduce watering in winter. Check the top few centimeters of soil; if dry, it's time to water.

Overwatering can lead to root rot.

Prune in late winter or early spring before new growth begins. Remove dead, damaged, or crossing branches. Prune to shape the tree and improve air circulation.

Light pruning can also be done after flowering to encourage a second bloom.

Propagate Lagerstroemia subcostata from seeds sown in spring or from semi-hardwood cuttings taken in summer. Seeds require stratification.

Cuttings should be treated with rooting hormone and kept in a humid environment until established.

Repot young plants every 1-2 years in spring. Mature trees generally do not require frequent repotting and prefer being slightly root-bound.

Use a well-draining potting mix and a slightly larger pot, ensuring not to disturb the root ball excessively.