Real World Gardener Black Bean Tree in Plant of the Week

April 8th, 2020


Common Name: Black Bean Tree: 
Scientific name: Castanospermum australe
Family: Fabaceae
Native distribution: east coast of Australia in Queensland and New South Wales, and to the Pacific islands of Vanuatu, New Caledonia
Over the last few weeks in this segment, we’ve been talking about big, big trees, and today’s offering is no exception, but perhaps not as big as the Kauri Pine. 
This tree, although very range with amazing huge boat like seed pods, is in the same family as peas, beans and broadbeans.

Castanospermum australe

The Black Bean tree makes an interesting pot specimen. 

Lovely red and yellow pea like flowers, typical of the legume family.
I'm talking with Adrian O”Malley, horticulturist and native plant expert. 
So let’s find out more. 

PLAY: Castanospermum austral_18th March 2020 

  • Black bean tree is an attractive Australian rainforest tree with dark glossy leaves and masses of yellow and red flowers during summer. 
  • Flowers attract lorikeets and other nectar feeders.
Sometimes used as street trees as long as they’re not under power lines. 
DO NOT plant in the garden, because it has invasive roots.
Certainly bird attracting when in flower and has a spreading canopy when it matures. 
If you want to grow it from the large bean like seed, sow the seed so that half of it is inserted into the seed raising mix.

Attractive pea like flowers of Castanospermum australe
Sometimes sold as a novelty plant with 6-10 seeds in a small pot, sort of like a bonsai plant but with many stems.
Unless you have a large garden, we recommend that you can plant this one successfully in a pot for many years. 
  • The beans of Castanospermum austral or black bean tree or toxic to everyone. 
Sydney Botanic gardens have a couple of these trees and various suburbs such as Hunters Hill, have the occasional Black Bean tree as a street tree.
seed pods of Black Bean tree.

If you have any questions either for me or for Adrian, why not write in to

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