Albizia procera aka White Siris

Albizia procera is relatively easy to grow within its suitable climate range (USDA zones 10-12), as it tolerates a wide variety of soil types and conditions once established. However, it is strictly a tropical/subtropical tree that cannot tolerate frost, limiting where it can be grown. The main challenge is its massive size—reaching 25-30 metres in height and spread—which makes it unsuitable for small gardens. It also has weedy tendencies and produces root suckers when roots are damaged.

Albizia procera prefers moist soil but becomes remarkably drought-tolerant once established. Young trees should be watered regularly during their establishment period. Mature trees can survive in areas receiving as little as 100mm annual rainfall, though they perform best with consistent moisture. The species thrives across a remarkably wide rainfall range of 100-5,000mm annually, demonstrating exceptional adaptability to both dry and wet conditions.

Albizia procera is exceptionally adaptable to different soil types, growing successfully in light sandy, medium loamy, and heavy clay soils. It tolerates nutritionally poor, dry, sandy, stony, and shallow soils, and can even succeed in moderately saline and alkaline conditions. The main requirement is reasonable drainage—the tree prefers well-drained soil. As a nitrogen-fixing legume, it actually improves soil fertility over time through its symbiotic relationship with Rhizobium bacteria.

Albizia procera is a tropical/subtropical tree that tolerates an extraordinarily wide temperature range of 1-46°C for mean annual temperatures. However, it is frost-tender and cannot survive in areas with regular freezing temperatures. It is hardy only in USDA zones 10-12 and UK hardiness zone 10. In its native range, it grows from sea level to approximately 1,500 metres elevation, preferring warm, humid conditions typical of monsoon climates.

Albizia procera is most successfully propagated from seed, with fresh seeds achieving 90-100% germination rates. Stored seeds require pre-treatment: immerse in boiling water for 5 seconds, then soak overnight in cooling water. Alternatively, propagation by stem or root cuttings is possible outside peak wet or dry seasons, and the tree readily produces root suckers that can be separated.

Albizia procera is a large, fast-growing deciduous tree reaching 25-30 metres in height with an equally broad spreading crown of 25 metres or more. The trunk can grow branchless for up to 9 metres and reach 60cm in diameter. Growth is rapid, with a mean annual diameter increment of 1-4 cm, meaning trees can achieve 40-60 cm diameter in 30 years. The open canopy creates a spreading, umbrella-like silhouette characteristic of many Albizia species.

Albizia procera produces fragrant flower heads shortly after new leaves emerge, typically between April and October depending on location. Each flower head contains approximately 20 sessile flowers with yellow-white corollas and prominent stamens that extend beyond the petals, creating the characteristic fluffy, brush-like appearance. Flowering is followed by flat, strap-shaped seed pods measuring 10-15 cm long, each containing 8-12 seeds. Major fruit production occurs in late summer to autumn.

Albizia procera is pollinated by insects, primarily bees and butterflies attracted to its fragrant flower heads. The flowers feature prominent stamens extending well beyond the corolla, making the nectar accessible to various pollinating insects. The species relies on cross-pollination for fruit production, though like many Albizia species, some self-pollination may occur.

Albizia procera must be grown outdoors—it is far too large for container cultivation and requires full sun that cannot be provided indoors. It thrives in USDA hardiness zones 10-12, where temperatures remain frost-free. The tree is native to tropical and subtropical Asia and has been successfully introduced to Florida, the Caribbean, Hawaii, and similar climates. It cannot survive in temperate regions with regular winter frosts.

Albizia procera is native to tropical and subtropical Asia, with a remarkably wide distribution extending from the Indian subcontinent (India, Nepal, Sri Lanka, Bangladesh) through Southeast Asia (Myanmar, Thailand, Malaysia, Cambodia, Laos, Vietnam, Philippines, Indonesia) to Papua New Guinea and northern Australia (Queensland, Northern Territory). It naturally occurs in monsoon forests, mixed deciduous forests, savannah woodlands, and open secondary forests, particularly in areas with a pronounced dry season.

Albizia procera is notably resistant to several species of termites, which is one reason its timber is valued for construction. However, like other Albizia species, it can be susceptible to the Albizia borer and various fungal diseases in humid conditions. Root rot may occur in poorly drained soils. The leaves themselves have insecticidal properties and are used in traditional fish poisoning, suggesting natural pest resistance. Overall, the species is considered relatively trouble-free in suitable climates.

Albizia procera has limited edibility, rated 1 out of 5 by PFAF. The young leaves can be cooked and eaten as vegetables in some cultures. During food scarcity, the inner bark has been ground into powder and mixed with flour to extend food supplies. A gum similar to gum arabic can also be extracted from the tree. However, caution is advised as the seeds contain proceranin A, a compound toxic to rodents, and the tree produces hydrocyanic acid.

Albizia procera has traditional medicinal uses, rated 2 out of 5 by PFAF. A decoction of the bark is used to treat rheumatism and hemorrhage, as well as pregnancy complications and stomach ache. The leaves are applied as poultices for treating ulcers. Research has indicated that all parts of the plant show anti-cancer activity, though this requires further scientific validation. These uses are primarily documented in traditional medicine systems of South and Southeast Asia.

Albizia procera is highly valued for non-food uses, rated 4 out of 5 by PFAF. The timber is excellent for construction, furniture, veneer, flooring, boat building, and carving, with notable resistance to termites. It is also used for fuel wood and makes good charcoal. The bark provides tanning and dyeing materials. The wood pulp is suitable for paper production. As a nitrogen-fixing tree, it enriches soil and is used in agroforestry, windbreaks, firebreaks, and for shade in plantations. The leaves have insecticidal and fish-poisoning (piscicidal) properties.

Albizia procera can be coppiced and managed through regular cutting if desired, as it responds well to cutting and readily produces new shoots. However, care should be taken as the tree produces vigorous root suckers when roots are damaged or exposed, which can lead to unwanted spread. For timber production, the trunk naturally grows branchless for up to 9 metres. In landscape settings, formative pruning of young trees can help establish a single straight trunk and balanced canopy structure.