Albizia julibrissin Durazz.
Mimosa, Silktree, Silky Acacia| Threat Level | Category |
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| Established | Tree |
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Similar Species May be confused with the following native and/or non-native species. Landscape Alternatives lists native horticultural substitutes |
Chamaecrista fasciculata Desmanthus illinoensis Mimosa microphylla Landscape Alternatives |
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Description
Height
Mimosa can reach heights of 20-40 feet (6-12 m). Sprouts can grow over 3 feet (1 m) in a season. Trunks may be single or multiple stems.Bark
The thin, light gray bark is nearly smooth with raised corky dots and dashes (lenticles).Twigs
Moderately slender to stout twigs are lime green turning shiny gray brown with many light-colored lenticels. Twigs are often slightly fluted below the nodes. Buds are superimposed and there is no terminal bud.Leaves
Feathery, fernlike deciduous leaves are alternate, 8-20 inches (15-50 cm) long. Leaves are bipinnately compound with 10-24 pinnae and 40-60 leaflets per pinnae. Leaflets are aymmetric, .5 inch (1-1.5 cm) with the midrib near one margin and parallel to it. Margins are smooth.Flowers
Showy pink blossoms are 1.5-2 inches (3.8-5.0 cm) long and are arranged in paniculate heads at the ends of branches. They are composed of 15-25 sessile flowers with numerous, conspicuous stamen filaments. Their fragrance is strong and sweet. Blooms May-August, sometimes longer.Fruit
Flat, light brown, oval seeds are about 0.5 inch (1.2 cm) long. they are borne in flat, linear, straw-colored pods about 6 inches (15 cm) long that form large clusters. The light green pods ripen August-September turn brown and begin to split releasing 5 to 10 oval seeds per pod. Pods can remain on the trees into winter.Images
Photo: Ted Bodner, Southern Weed Science Society, Bugwood.orgMore images of Albizia julibrissin.
Life History
Albizia julibrissin is commonly known as mimosa, silk tree, or silky acacia and is in the Fabaceae or Pea Family. This hardy tree is a popular ornamental because of its fragrant and showy flowers. The tree seeds prolifically and resprouts quickly when cut. It inhabits many of the cut-and-fill slopes along roads as well as disturbed areas and stream banks throughout Tennessee.Mimosa seeds have impermeable seed coats that allow them to remain dormant for years. One study showed 90% viability after five years; another Albizia species had 33% germination of seeds after 50 years in opend storage. The trees grow rapidly under good conditions but have weak, brittle wood and are short-lived. They resprout quickly if cut or top-killed. Mimosa is susceptible to a fungus, mimosa wilt, that infects the root system and can be fatal.
Habitat
Mimosa occurs on dry-to-wet sites and spreads along stream banks, preferring open conditions but also persisting in shade. Seldom found above 3,000 feet (900 m). It forms colonies from root sprouts and spreads by abundant animal- and water-dispersed seeds. It fixes nitrogen in the soil.Origin and Distribution
There are about 50 species of the genus in subtropical and tropical Asia, Africa, and Australia. Mimosa is native to Asia, from Iran to China and was introduced to the U.S. in 1745. It is established from Virginia to Louisiana, and in California. Other states where invasive: DC, FL, GA, KY, LA, MA, NC, NJ, SC, VA, WV.Sources: Information on this plant page derived primarily from the Tennessee Management Manual and James H. Miller's Nonnative Invasive Plants of Southern Forests, USDA Forest Service.
Management Recommendations
Mechanical Controls
Cutting: Cut trees at ground level with power or manual saws. Cutting is most effective when trees have begun to flower to prevent seed production. Because mimosa spreads by suckering, resprouts are common after treatment. Cutting is an initial control measure and will require either an herbicidal control or repeated cutting for resprouts.Girdling: Use this method on large trees where the use of herbicides is impractical. Using a hatchet, make a cut through the bark encircling the base of the tree, approximately 15 cm (6 in) above the ground. Be sure that the cut goes well into or below the cambium layer. This method will kill the top of the tree but resprouts are common and may require follow-up treatments for several years until roots are exhausted.
Hand Pulling: Mimosa is effectively controlled by manual removal of young seedlings. Plants should be pulled as soon as they are large enough to grasp, but before they produce seeds. Seedlings are best pulled after a rain when the soil is loose. The entire root must be removed since broken fragments may resprout.
Biological Controls
Mimosa Wilt: Fusarium oxysporum f. perniciosum is a fungus that attacks mimosa in the U.S. and is transferred through the soil. It infects its host through the root system and may be fatal to the tree. It is not used at present and further research is needed.Herbicidal Controls
Foliar Spray Method
This method should be considered for large thickets of mimosa seedlings where risk to non-target species is minimal. Air temperature should be above 65°F to ensure absorption of herbicides.Glyphosate: Apply a 2% solution of glyphosate and water plus a 0.5% non-ionic surfactant to thoroughly wet all leaves. Use a low pressure and coarse spray pattern to reduce spray drift damage to non-target species. Glyphosate is a non-selective systemic herbicide that may kill non-target partially-sprayed plants.
Triclopyr: Apply a 2% solution of triclopyr and water plus a 0.5% non-ionic surfactant to thoroughly wet all leaves. Use a low pressure and coarse spray pattern to reduce spray drift damage to non-target species. Triclopyr is a selective herbicide for broadleaf species. In areas where desirable grasses are growing under or around mimosa, triclopyr can be used without non-target damage.
Cut Stump Method
This control method should be considered when treating individual trees or where the presence of desirable species preclude foliar application. Stump treatments can be used as long as the ground is not frozen.Glyphosate: Horizontally cut stems at or near ground level. Immediately apply a 50% solution of glyphosate and water to the cut stump, covering the outer 20% of the stump.
Triclopyr: Horizontally cut stems at or near ground level. Immediately apply a 50% solution of triclopyr and water to the cut stump, covering the outer 20% of the stump.