This fast-growing, deciduous tree has a low branching, open, spreading habit and delicate, lacy, almost fern-like foliage. Fragrant, silky, pink puffy pompom blooms, two inches in diameter, appear from late April to early July creating a spectacular sight.
But the tree produces numerous seed pods and harbors insect (webworm) and disease (vascular wilt) problems. Although short-lived (10 to 20 years), Mimosa is popular for use as a terrace or patio tree for its light shade and tropical look.
Scientific name: Albizia julibrissin
Pronunciation: al-BIZ-zee-uh joo-lih-BRISS-in
Common name: Mimosa, Silktree
USDA hardiness zones: USDA hardiness zones: 6B through 9
Origin: not native to North America
Uses: near a deck or patio; reclamation plant; specimen
Availability: generally available in many areas within its hardiness range
Several cultivars exist: 'Alba' has white flowers; 'Rosea' ('Ernest Wilson') has bright pink flowers, is hardier than the species, and is 10 to 15 feet in height; 'Rubra' has deep pink flowers. 'Charlotte', 'Tyron', and 'Union' are reportedly wilt resistant and may be coming into production in selected nurseries in some areas.
Height: 15 to 25 feet
Spread: 25 to 35 feet
Crown uniformity: irregular outline or silhouette
Crown shape: spreading; vase shape
Crown density: open
Growth rate: fast
Trunk and Branches:
Trunk/bark/branches: bark is thin and easily damaged from mechanical impact; droop as the tree grows, and will require pruning for vehicular or pedestrian clearance beneath the canopy; routinely grown with, or trainable to be grown with, multiple trunks;
Breakage: susceptible to breakage either at the crotch due to poor collar formation, or the wood itself is weak and tends to break
Current year twig color: gray
Current year twig thickness: stout
Leaf arrangement: alternate
Leaf type: bipinnately compound; odd pinnately compound
Leaflet margin: ciliate; entire
Leaflet shape: lanceolate; oblong
Leaflet venation: pinnate
Leaf type and persistence: deciduous
Leaflet blade length: less than 2 inches
Leaf color: green
Fall color: no fall color change
Flower color: pink
Flower characteristics: pleasant fragrance; showy; spring flowering; summer flowering
Without warm summers the wood quickly becomes damaged and fails to flower. In colder areas, plant near a high wall for heat retention. Prune in the spring (only if necessary) taking the previous year's growth back to five or six buds.
Light requirement: tree grows in full sun
Soil tolerances: clay; loam; sand; acidic; alkaline; extended flooding; well-drained
Drought tolerance: high
Aerosol salt tolerance: moderate
Growing best in full sun locations, Mimosa is not particular as to soil type but has low salt-tolerance. Grows well in acid or alkaline soil. Mimosa tolerates drought conditions well but has a deeper green color and more lush appearance when given adequate moisture.
The litter problem of the blooms, leaves, and especially the long seed pods requires consideration when planting this tree. Also the wood is brittle and has a tendency to break during storms though usually the wood is not heavy enough to cause damage. Typically, most of the root system grows from only two or three large-diameter roots originating at the base of the trunk. These can raise walks and patios as they grow in diameter and makes for poor transplanting success as the tree grows larger.
Unfortunately, Mimosa (vascular) wilt is becoming a very widespread problem in many areas of the country and has killed many roadside trees. Despite its picturesque growth habit and its beauty when in bloom, some cities have passed ordinances outlawing further planting of this species due to its weed potential and wilt disease problem.