Seed capsules are club shaped, dry and woody and contain 2 seeds. Plants also sucker readily and new clumps appear regularly beside established plants. As pruning is tolerated well, it is easy to establish a hedge or windbreak when suckers emerge. G.excelsum has proven to be reliable in a range of climates from tropical to cool temperate. Best flowering is achieved in full sun or only light scattered shade and nectar feeding birds find the flowers irresistible.
Propagation is easy from cuttings or by transplanting suckers.
Seed also germinates well from fresh seed. You may have reached this description from one of several different sources.