Mimosa (Albizia julibrissin) is a small, flowering tree in the Mimosaceae family. It is also known as the silk tree, silky acasia or Persian silk tree. Its most characteristic features are bi-pinnate,compound leaves and showy pink flowers. It produces numerous, flat, brown, seed pods in late summer.

Originally from a region encompassing Iran (Persia) to China and Korea, it is widely planted as an ornamental tree in the west (particularly in Europe). It is hardy in U. S. Hardiness Zones 6 - 9. Mimosa trees grown quickly, often adding 2 feet of growth per year and reach a maximum height of 20 - 40 feet in 10 to 20 years.

Although mimosa trees have many attractive features and can make an ornamental specimen plant on a lawn, there are a number of  important reasons not to plant it in your garden. First, it is an invasive species in many parts of the United States, especially in the Mid-Atlantic and Southeast, and of concern in others. Silk trees grow vigorously and displace native trees and shrubs, spreading by seed and vegetative means. It is difficult to remove due to the numerous long-lived seeds and its ability to re-sprout vigorously. Conversely, your specimen tree will be short-lived, surviving only 10 to 20 years in the Northeast. Third, its branches are brittle and it poses a serious litter problem from broken branches, the flowers and seed pods. Interestingly, they are also allelopathic, meaning that they have a mechanism to prevent other plants from growing near-by.

Courtesy of the NYBG Plant Information Service