Popcorn Cassia Information: What Is Popcorn Cassia

popcorn cassia
popcorn cassia
(Image credit: PlazacCameraman)

Popcorn cassia (Senna didymobotrya) earns its name in a couple ways. One very obvious one is its flowers - spikes sometimes reaching up a foot (30cm.) in height, covered in round, bright yellow flowers that look an awful lot like their namesake. The other is its scent - when they’re rubbed, the leaves are said by some gardeners to give off a scent just like that of freshly buttered popcorn. Still other gardeners are less charitable, likening the smell more to wet dog. Smell disputes aside, growing popcorn cassia plants is easy and very rewarding. Keep reading to learn more popcorn cassia information.

What is Popcorn Cassia?

Native to central and eastern Africa, the plant is a perennial at least in zones 10 and 11 (some sources list it as hardy down to zone 9 or even 8), where it can grow up to 25 feet (7.5 m.) tall. It often tops out at 10 feet (30 m.), however, and stays even smaller in cooler climates. Even though it’s extremely frost tender, it grows so quickly that it can be treated as an annual in colder zones, where it will grow to only a few feet (91 cm.) in height but will still bloom vigorously. It can also be grown in containers and brought indoors for the winter.

Popcorn Cassia Care

Popcorn cassia care is not too difficult, though it does take some upkeep. The plant thrives in full sun and rich, moist, well-drained soil. It is a very heavy feeder and drinker, and should be fertilized often and watered frequently. It grows best in the hot and humid days of high summer. It will actually tolerate a very light frost, but container plants should be brought indoors when autumn temperatures start to fall toward freezing. It can sown as seed in very early spring, but when growing popcorn cassia as an annual, it’s best to get a head start by planting cuttings in the spring.

Liz Baessler
Senior Editor

The only child of a horticulturist and an English teacher, Liz Baessler was destined to become a gardening editor. She has been with Gardening Know how since 2015, and a Senior Editor since 2020. She holds a BA in English from Brandeis University and an MA in English from the University of Geneva, Switzerland. After years of gardening in containers and community garden plots, she finally has a backyard of her own, which she is systematically filling with vegetables and flowers.