Cassia can be either hardy perennial or annuals.
They generally reach an height of 60 cm to 1.2m in height, and resemble small perennial trees.
Cassia javanica - Pink shower tree by Tatters.
They have the common names of Wild Senna, Candle bush (Cassia alata) American Senna, Golden shower tree (Cassia fistula) and Partridge tree.
Cassia have small pea shaped yellow flowers.
Senna Macranthera by Mauroguanandi.
Common Names: Senna, Pink Cassia, Desert Cassia, Golden Shower Tree, Pink Shower tree, Sicklepod, Wild Senna, Kassod Tree, Appleblossom Shower, Sensitive Pea, Partridge pea.
Life Cycle: Hardy annual. Hardy perennial.
Height: Garden species: 24 to 300 inches (60 to 750 cm).
Native: Mainly to tropical regions, though some species are native to temperate areas.
Growing Region: Zones 6 to 11.
Flowers: Mainly summer. Some species flower in autumn/winter.
Flower Details: Yellow, pink, orange-red. Senna: Pea-like.
Foliage: Green. Compound leaves. May be evergreen.
Sow Outdoors: 1/8 inch (3mm). Summer or autumn. Spacing: Small species: 24 to 36 inches (60 to 90cm); large species (trees) 25 to 30 feet (7.5 to 9 metres).
Sow Indoors: Chip seeds. Soak in water for three hours. Germination time: one week to three months. Temperature 70 to 75°F (21 to 24°C). Seven or eight weeks before transplanting outdoors; either following the last frost or in autumn.
Requirements: Full sunlight or light shade. Good drainage. Regular watering. Regular feed. Thin plants in the autumn. Taking cuttings in spring. Divide in spring.
Closely Related Species:
Miscellaneous: Many species are now included within the Senna and Charmaecrista genera; classification of species into these genera is still ongoing. Synonymous with Carthartocarpus. Do not confuse the genus name Cassia with one of the common names for Cinnamon: Cassia; this is a member of the genus Cinnamomum.
If planning to grow Cassia outdoors from the off it is best to sow out the seed in either Summer or autumn at a depth of 3 mm.
Wild Senna-like species should be grown in soil that has good drainage, in either a sunny or partly shaded part of the garden.
When growing Cassia indoors first then you will first need to chip the seeds, then soak in warm water for three hours before sowing.
They should be planted about 7 weeks before you transplant the seedlings outdoors, in the autumn or after the last frost of the spring. When putting the seedlings out they should be spaced at about 60 to 90 cm apart (24 to 36 inches).
Once established Cassia requires regular fertilisation and watering; ideally they should be thinned in the autumn.