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.

This plant is not native to the Northeast, but has been widely introduced in large areas of the Midatlantic and South-Central United States. 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 USDA 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 factors to weigh before planting 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. It is not at this time on the invasive species list in New York State but it is currently being monitored for invasive potential (Tier M) by Long Island and Lower Hudson Valley Invasive Species Management.  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