Let the Castanospermum's soil moderately dry between the waterings. Sitting in water can lead to root rot and has to be avoided. It will enjoy being stood outside in a rain shower which will also remove any dust that has collected on the leaves – spraying regularly will help prevent dust build up.

Frequent pruning can control growth and form the Castanospermum australe into a bonsai-like short ornamental tree. This tree can be grown indoors or outdoors in a container.

The seeds are poisonous.