Sieber's Cassia Plant Care

Sieber's Cassia (Cassia sieberiana) belongs to the Fabaceae family within the Cassia genus. Sieber's Cassia is native to Africa. Sieber's Cassia is also known as African Laburnum, Cassia conspicua, Cassia javanica.

Sieber's Cassia displays a small to medium-sized tree growth habit, reaching up to 20 ft tall with a spread of approximately 15 ft. Sieber's Cassia produces showy clusters of yellow flowers.

Leaf size: approximately 6 inches.

Water a young or newly planted Sieber's Cassia every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Sieber's Cassia thrives in full sun to partial shade.

Cassia sieberiana tolerates temperatures of 60–85°F. Sieber's Cassia prefers humidity levels of 40–70%.

Well-draining sandy loam with added organic matter for moisture retention. Good drainage is essential for Sieber's Cassia to prevent waterlogging, which leads to root rot and fungal issues.

Feed Sieber's Cassia every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to partial shade and well-draining sandy loam with added organic matter for moisture retention. Avoid low spots where water collects after rain.

Sieber's Cassia is suited to USDA Zone 10a – 12b.

Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.

Sieber's Cassia can spread to about 15 ft (4.6 m) and reach about 20 ft (6 m) tall. Space plants about 15 ft (4.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the tree spacing calculator.

Prune Sieber's Cassia while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.

Sieber's Cassia is frost-tender (hardy to USDA zone 10). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Sieber's Cassia can be propagated through seeds, softwood cuttings. Similar propagation techniques also apply to shorthorn senna plant care, which shares the same genus.

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Sieber's Cassia is susceptible to aphids, caterpillars, scale insects. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Sieber's Cassia grows outdoors in USDA Zone 10a – 12b. It survives winters down to planting zone 10a. Sieber's Cassia is native to Africa. In cooler regions, grow Sieber's Cassia as a houseplant or bring it indoors before the first frost.