Cassia nodosa Seeds | Pink Shower Tree
LATIN NAME: Cassia nodosa
COMMON NAME: Pink Shower Tree
Plant Profile
The Pink Shower Tree is a medium deciduous tree of the pea family from Malaysia and mainland Southeast Asia, and in the flowering season its branches carry dense clusters of rose-pink flowers along their length, opening deeper pink and fading through towards white so that a mature tree shows a blend of shades at once, the origin of its pink-and-white shower nickname. The pinnate leaves are fine and rather feathery, the crown broad and rounded at eight to fifteen metres, and the long, dark pods hang in the dry season.
It is a favourite avenue tree across the tropical world for the reliability of its bloom, which arrives in late spring and holds for weeks. In flower it is one of the handsomest of all tropical street trees, and out of flower it is a competent, light-crowned shade tree.
Science & Biotechnology
Current taxonomy treats this tree as a variety of the Java cassia complex, Cassia javanica var. nodosa, one of a cluster of closely related, partly intergrading forms across Southeast Asia whose boundaries the old garden labels flattened; the molecular work that reshaped the group also moved many of the shower trees between Cassia, Saraca and allies. Its flowering is less strictly leafless than its Thai relative, arriving with the new foliage, and urban-forestry studies of tropical street trees have used its reliable, consistent performance as a benchmark in assessments of flowering avenue species. Its pods, like those of its relatives, carry hard-coated seed with physical dormancy.
Seed-grown trees vary in flower shade, and the trade propagates the best pink forms vegetatively to keep the colour consistent.
Uses & Benefits
Its garden use is the reliable, weeks-long pink-and-white flowering of a large avenue or specimen tree, scaled for parks, wide verges and gardens with room. The light, feathery canopy lets grass and underplanting survive beneath it, and the dry-season pods are taken apart by seed-eating birds and by squirrels in its adopted ranges.
It shares its family’s senna chemistry, the source of the world’s standardised laxative compounds, but its own value in cultivation is ornamental and civic rather than medicinal. In Thailand and Malaysia its bloom is a seasonal marker, and older planted avenues of it are protected as landmarks in several towns.
Growing from Seed
Scarify the hard seed coat with a file or a pour of boiling water, soak overnight and sow into a loose, free-draining tropical mix at 24 to 30 °C; germination follows within one to two weeks and the seedlings push fast. Pot on regularly and grow them in full sun with steady water through the season.
Plant out into deep, well-drained soil in full sun, spacing avenue trees at ten metres, and water through the first two dry seasons. It establishes readily, flowers within five to seven years, and once its roots are down it manages itself. Prune young trees only to build a clean trunk and an open crown.
Our Take
The pink-and-white avenue tree of tropical Asia, weeks of reliable bloom over a light, feathery crown. For parks and large gardens in the tropics, a benchmark flowering tree.
Related Reading
More species in the same orbit as Pink Shower Tree: