Albizia julibrissin
silk tree
Iran and the Caucasus east through China, Korea, and Japan; naturalized and invasive in the southeastern United StatesLearn more
Overview
Albizia julibrissin is silk tree (mimosa), a deciduous tree growing 20-40 feet (6-12 m) tall and 20-40 feet (6-12 m) wide with a broad vase-shaped spreading canopy. Bipinnately compound (fern-like) leaves 10-20 inches (25-50 cm) long with many small leaflets 0.4 inch (1 cm) — the leaflets fold closed at night (nyctinastic movement) and during rain. Pink fluffy globular flower heads 1.5-2 inches (4-5 cm) composed of long silky stamens in June-September. Flat brown seed pods 5-8 inches (13-20 cm) persist through winter. In the legume family (Fabaceae) — nitrogen-fixing via root nodule symbiosis. Native to Iran through Japan. Classified as invasive in the southeastern United States — self-sows aggressively in disturbed areas, roadsides, and forest edges from abundant viable seed. Mimosa wilt (Fusarium oxysporum f. sp. perniciosum) is a lethal vascular disease with no cure — kills established trees. These two limitations (invasive spread and mimosa wilt) are the primary concerns. Short-lived: 15-25 years. Brittle wood breaks in storms. The spent flowers, petals, leaf litter, and pods create year-round debris. Toxic to pets (saponins). Drought-tolerant once established. Zones 6-9. Full sun. Growth rate is fast.
Native Range
Native to Iran and the Caucasus east through China, Korea, and Japan. Classified as invasive in the southeastern United States.Suggested Uses
Grown as a shade tree in residential gardens where invasive status allows. Classified as invasive in the southeastern US — check local regulations before planting. Fern-like foliage. Pink summer flowers. Tolerates heat and drought. Messy (debris year-round). Short-lived. Toxic to pets. Zones 6-9.How to Identify
Appearance
Size & Dimensions
Height20' - 40'
Width/Spread20' - 40'
Reaches mature size in approximately 8 years
Bloom Information
Summer (June-September). Pink fluffy globular flower heads 1.5-2 inches (4-5 cm) composed of long silky stamens. 10 weeks of bloom. Bee-, butterfly-, and hummingbird-pollinated. Flat brown seed pods 5-8 inches (13-20 cm) follow and persist through winter.Detailed Descriptions
Flower Description
Pink, fluffy globular heads 1.5-2 inches (4-5 cm) composed of long silky stamens — the source of the common name 'silk tree'Foliage Description
Medium green, bipinnately compound (fern-like), 10-20 inches (25-50 cm) long with many small leaflets 0.4 inch (1 cm) long; the leaflets fold closed at night (nyctinastic movement) and during rain; turns yellow in fall before dropping late in the seasonGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Full sun (6+ hours). Any well-drained soil pH 5.5-7.5. Drought-tolerant once established. Classified as invasive in the southeastern US — check local regulations. Mimosa wilt (Fusarium oxysporum) is lethal with no cure. Short-lived (15-25 years). Brittle wood. Prune in winter. Toxic to pets. Zones 6-9.Pruning
Prune during winter dormancy (November-February). Remove dead, crossing, or storm-damaged branches. The broad vase shape is natural. Brittle wood — structural pruning when young to develop strong branch attachments. Remove seedlings from the garden to limit invasive spread.Pruning Schedule
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winter