Cassia Rainbow

Rainbow shower is the sterile hybrid of Cassia fistula and Cassia javanica, and it does something neither parent manages alone: it carries gold, apricot and pink flowers on the same tree at the same time, in long pendulous showers through summer. The foliage is fine and pinnate, the crown broad and spreading, and because the tree is sterile it sets no seed pods.

In the landscape

Rainbow shower is a shade and flowering tree for open ground, a broad, spreading crown that wants 8–12 m of room and rewards it with a summer canopy of colour visible from a long way off. It suits parkland, resort and large private plantings, wide coastal avenues at 10–12 m centres, and lawn specimens where the full spread can be seen. Because the hybrid is sterile it sets no pods, which removes the litter problem that rules out many tropical flowering trees near paving and pools.

Growing notes

Semi-deciduous, dropping foliage briefly in the dry season and reshooting with the flowers. It is a tropical and subtropical tree: frost tender, and best kept to coastal and near-coastal Queensland, the warm north of New South Wales and the tropical north generally. Give it full sun and free-draining soil; once established it carries drought well and tolerates coastal wind. Growth is fast in warmth. Mature size in the ground is roughly 9–12 m tall by 8–12 m wide.

This tree

• Currently standing: 60 trees

Field-grown ex-ground at Donkin Farm, Utchee Creek, root-pruned and basket-lifted, delivered and craned Australia-wide, price on application through the Shortlist.