Justicia betonica

Justicia betonica is one of those plants that stops you mid-stride. The flower spires are unlike anything else in a tropical garden — slim, upright and architectural, built from overlapping papery white bracts traced with fine green veining, each one enclosing a delicate pale pink flower. In full flush the effect is showy without being loud, the kind of elegant, unusual display that makes visitors ask what it is and where you got it.

It’s a genuinely rare plant in Australian cultivation, which is a shame because it’s exceptionally well suited to tropical and subtropical gardens further south where summers are warm and winters are mild. Sydney gardeners in particular will find it thrives — the profuse summer flowering is at its best in exactly that kind of warm, humid growing season, and the plant brings something to a tropical-style garden that nothing more common can quite replicate.

Growing to around 1.5 metres, it’s a well-mannered shrub that responds readily to pruning, so you can keep it shaped and compact or let it fill out naturally into a rounded, flowering specimen. Use it as a feature plant where those extraordinary spires can be appreciated up close, or as part of a mixed tropical border where its upright flowering habit adds vertical interest among broader-leaved companions.

A note for Southeast Queensland gardeners: Justicia betonica can naturalise and become weedy in the warm, humid conditions of SE Queensland and is probably not the best choice for gardens in that region. It’s best suited to Sydney, the NSW coast, and similar climates where conditions keep it under control.

For more information on cool tolerant tropical gardening