Californian Senna Plant Care

Californian Senna (Senna multiglandulosa) belongs to the Fabaceae family within the Senna genus. Californian Senna is native to Mexico, Guatemala, and western parts of South America. Californian Senna is also known as Spanish Bayonet, Desert Senna, Adipera tomentosa.

Californian Senna displays an upright, spreading shrub growth habit, reaching up to 5 ft tall with a spread of approximately 5 ft. Californian Senna produces bright yellow, pea-like flowers in clusters.

Leaf size: approximately 4 inches.

Water a young or newly planted Californian Senna 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.

Californian Senna thrives in full sun to partial shade.

Senna multiglandulosa tolerates temperatures of 60–85°F. Californian Senna prefers humidity levels of 40–70%.

Well-draining sandy loam with added organic matter. Good drainage is essential for Californian Senna to prevent waterlogging, which leads to root rot and fungal issues.

Feed Californian Senna 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. Avoid low spots where water collects after rain.

Californian Senna is suited to USDA Zone 8b – 11b.

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.

Californian Senna can spread to about 5 ft (1.5 m) and reach about 5 ft (2 m) tall. Space plants about 5 ft (1.5 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 Californian Senna 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.

Californian Senna is hardy down to USDA zone 8b, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown trees need extra protection: roots in a pot freeze much more easily than roots in the ground.

Californian Senna can be propagated through seeds, softwood cuttings. Similar propagation techniques also apply to alexandrian senna plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Californian Senna is susceptible to aphids, caterpillars, spider mites. 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.

Californian Senna grows outdoors in USDA Zone 8b – 11b. It survives winters down to planting zone 8b. Californian Senna is native to Mexico, Guatemala, and western parts of South America.