Siris tree Plant Care

Siris tree (Hymenolobium excelsum) belongs to the Fabaceae family within the Hymenolobium genus. Siris tree is native to Central America and northern South America, ranging from Honduras to Bolivia and southeastern Brazil. Siris tree is also known as Brazilian ironwood.

Siris tree displays a tall canopy tree growth habit, reaching up to 60 ft tall with a spread of approximately 30 ft. Siris tree produces small yellow flowers in clusters.

Leaf size: approximately 6 inches.

Water a young or newly planted Siris tree every 7–14 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.

Siris tree thrives in full sun to partial shade.

Hymenolobium excelsum tolerates temperatures of 65–85°F. Siris tree prefers humidity levels of 50–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining loamy soil with added organic matter for nutrients. Good drainage is essential for Siris tree to prevent waterlogging, which leads to root rot and fungal issues.

Feed Siris tree 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 loamy soil with added organic matter for nutrients. Avoid low spots where water collects after rain.

Siris tree is suited to USDA Zone 11a – 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.

Siris tree can spread to about 30 ft (9.1 m) and reach about 60 ft (18 m) tall. Space plants about 30 ft (9.1 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 Siris tree 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.

Siris tree is frost-tender (hardy to USDA zone 11). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Siris tree can be propagated through seeds, stem cuttings.

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

Siris tree is susceptible to aphids, leaf miners, 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.

Siris tree grows outdoors in USDA Zone 11a – 12b. It survives winters down to planting zone 11a. Siris tree is native to Central America and northern South America, ranging from Honduras to Bolivia and southeastern Brazil. In cooler regions, grow Siris tree as a houseplant or bring it indoors before the first frost.