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FACT SHEET: SILK TREE

Silk Tree 

Albizia julibrissin Durz. 

Pea family (Fabaceae) 

NATIVE RANGE 

Iran to Japan (according to Hortus 3rd. ed.) 

DESCRIPTION 

Silk tree, also known as mimosa, or silky acacia, is a small to medium-sized 

tree that can grow up to 20-40 feet tall. The bark is light brown, nearly smooth, 

and generally thin with lens shaped areas along the stem. The attractive fernlike leaves of mimosa are finely divided, 5-8 inches long by about 3-4 inches 

wide, and alternate along the stems. Silk tree has showy and fragrant pink 

flowers, about 11⁄2 inches long, that resemble pom-poms and are arranged in 

panicles at the ends of branches. Fruits are flat, straw-colored pods about 6 

inches long containing light brown oval-shaped seeds about 1⁄2 inch in length. Pods ripen in August to September and 

begin to disintegrate soon after, but remain on the trees into winter. 

ECOLOGICAL THREAT 

Because silk tree can grow in a variety of soils, produce large seed crops, and resprout when damaged, it is a strong 

competitor to native trees and shrubs in open areas or forest edges. Dense stands of mimosa severely reduce the 

sunlight and nutrients available for other plants. 

DISTRIBUTION IN THE UNITED STATES 

Silk tree is naturalized from New Jersey to Louisiana and in California. 

HABITAT IN THE UNITED STATES 

Silk tree takes advantage of disturbed areas, often spreading by seed from 

nearby ornamentals or from contaminated fill dirt. It prefers full sun and is often 

seen along roadsides and open vacant lots in urban/suburban areas. Silk tree 

can tolerate partial shade but is seldom found in forests with full canopy cover, 

or at higher elevations (above 900 m or 3,000 ft), where cold hardiness is a 

limiting factor. It can, however, become a serious problem along riparian areas, 

where it becomes established along scoured shores and where its seeds are 

easily transported in water. Like many successful exotics, it is capable of growing in a wide range of soil conditions. 

BACKGROUND 

Silk tree was introduced to the U.S. in 1745. Silk tree continues to be a popular ornamental because of its fragrant and 

showy flowers. 

BIOLOGY & SPREAD 

Silk tree reproduces both vegetatively and by seed. Silk tree seeds have impermeable seed coats that allow them to 

remain dormant for many years. One study showed that 90% of the seeds were viable after five years and, for another 

species of mimosa, a third of its seeds germinated after 50 years in open storage. Seeds are mostly dispersed below or 

around the parent plant, but can be dispersed further by water. Silk trees grow rapidly under good conditions but are 

short-lived and have weak, brittle wood. If cut or top-killed, trees resprout quickly and sprouts can grow over three feet in a

season. 

MANAGEMENT OPTIONS 

Silk tree can be controlled using a variety of mechanical and chemical controls. 
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Plant Conservation Alliance®s Alien Plant Working Group 

Xeeds HoneXild: Alien Plant Invaders of Natural Areas 

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Mechanical 

Trees can be cut 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 is effective 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 six inches above the ground. Be sure that the cut goes well below the bark. 

This method will kill the top of the tree but resprouts are common and may require a follow-up treatment with a foliar 

herbicide. Hand pulling will effectively control young seedlings. Plants should be pulled as soon as they are large enough 

to grasp, but before they are old enough to flower. Seedlings are best pulled after a rain when the soil is loose. The entire 

root must be removed since broken fragments may resprout. 

Chemical 

Silk tree seedlings and small trees can be controlled by applying a 2% solution of glyphosate (e.g., Roundup®) or triclopyr 

(e.g., Garlon®) and water plus a 0.5% non-ionic surfactant to thoroughly wet all leaves. Systemic herbicides such as 

glyphosate and triclopyr can kill entire plants because the chemicals travel through a plant from the leaves and stems to 

the actively growing roots, where they prevent further cell growth. Use a low pressure and a coarse spray pattern to 

reduce damage from spray drift on non-target species. Use caution when applying these products, as glyphosate is a nonselective herbicide that may kill non-target plants that are only partially contacted. Triclopyr is a selective herbicide for 

many broadleaf plant species. Triclopyr is a selective herbicide for many broad-leaved plant species and should be 

considered for sites where native or other desirable grasses are meant to be conserved. 

The cut-stump and basal bark herbicidal methods 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. Horizontally cut stems at or near ground level. Immediately apply a 25% solution of glyphosate or triclopyr and 

water to the cut stump making sure to cover the outer 20% of the stump. Basal bark applications are effective throughout 

the year as long as the ground is not frozen. Apply a mixture of 25% triclopyr and 75% horticultural oil to the base of the 

tree trunk to a height of 12-15 inches from the ground. Thorough wetting is necessary for good control; spray until run-off 

is noticeable at the ground line. 

USE PESTICIDES WISELY: Always read the entire pesticide label carefully, follow all mixing and application instructions and wear all 

recommended personal protective gear and clothing. Contact your state department of agriculture for any additional pesticide use 

requirements, restrictions or recommendations. 

NOTICE: mention of pesticide products on this page does not constitute endorsement of any material.

CONTACT 

For more information on the management of silk tree, please contact: 

• Kris Johnson, Great Smoky Mountains National Park, Gatlinburg, TN 

SUGGESTED ALTERNATIVE PLANTS 

Many small to medium-sized trees make excellent alternatives to silk tree. A few examples include serviceberry 

(Amelanchier arborea), redbud (Cercis canadensis), flowering dogwood (Cornus florida), river birch (Betula nigra), fringe 

tree (Chionanthus virginicus), American holly (Ilex opaca), and sweetgum (Liquidambar styraciflua). Check with the native 

plant society in your state for plant recommendations for your particular area. 

OTHER LINKS 

• http://www.invasive.org/search/action.cfm?q=Albizia%20julibrissin

AUTHORS 

Tom Remaley, Great Smoky Mountains National Park, Gatlinburg, TN 

EDITORS 

Jil M. Swearingen, National Park Service, Washington, DC 

Larry Morse, The Nature Conservancy, Arlington, VA 
20 May 2005 Page 3 of 3 

Plant Conservation Alliance®s Alien Plant Working Group 

Xeeds HoneXild: Alien Plant Invaders of Natural Areas 

http://www.nps.gov/plants/alien/

PHOTOGRAPHS 

Tom Remaley, Great Smoky Mountains National Park, Gatlinburg, TN 

REFERENCES 

Bonner, F.T., M.S. Hooda, D.P. Singh. 1992. Moisture determination on seeds of honey locust and mimosa. Tree Plant 

Note, USDA Forest Service 43(3):72-75. 

Bransby, D.I., S.E. Sladden, G.E. Aiken. 1992. Mimosa as a forage plant: a preliminary evaluation. Proceedings of the 

Forage Grasslands Conference. Georgetown, Texas; American Forage and Grassland Council 1:28-31. 

Gleason, H.A., A. Cronquist. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. 2nd ed. 

The New York Botanical Garden, 910. 

Hartel, P.G., B.L. Haines. 1992. Effects of potential plant CO2 emissions of bacterial growth in the rhizosphere. Journal of 

Soil Biological Biochemistry and Science 24(3). 

Panizzi, A.R., F. Slansky, Jr. 1991. Suitability of selected legumes and the effect of nymphal and adult nutrition in the 

southern green stink bug (Hemiptera: Heteroptera: Pentatomidea). Journal of Econ-Entomology 84(1):103-113. 

Swearingen, J. 2009. WeedUS Database of Plants Invading Natural Areas in the United States: Mimosa (Albizia 

julibrissin). http://www.invasive.org/weedus/subject.html?sub=3004. 

USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 

70874-4490 USA.