March 2015

Invasive Watch: Mimosa Tree (albizia Julibrissen)

What to Look For
Mimosa tree, also known as silk tree, is a small to medium-sized deciduous tree that can grow up to 40 feet tall with single or multiple stems. The bark is light brown and smooth with lens-shaped areas along the stem. Mimosa tree leaves are alternate, finely divided and fernlike, usually 6 to 16 inches long and roughly 3 to 5 inches wide. The fragrant flowers are bright pink, resembling pompoms, and are arranged in clusters at the ends of branches. The plant develops a flat fruit pod in late summer.

Where It's Found
Mimosa tree is native to Asia and was introduced in the mid-1700s into the United States, where it has been widely used as an ornamental. It is known to invade any type of disturbed habitat and is commonly found in old fields and along roadsides, forest edges and stream banks. Once established, mimosa tree is difficult to remove, as its seeds are capable of living a long time and because of the plant’s ability to resprout vigorously.

How to Treat It
To effectively treat mimosa tree, apply Milestone® specialty herbicide at the labeled rate of 7 fluid ounces per acre plus 0.5 percent nonionic surfactant. Capstone® specialty herbicide is also effective at the labeled rate of 9 pints per acre plus 0.5 percent surfactant as a broadcast treatment or 5 percent to 8 percent product plus 0.5 percent nonionic surfactant as a foliar spot treatment. Coverage should be thorough to wet all leaves, stems and root collars — increasing the spray volume when the target vegetation is tall and/or dense. Apply the herbicide solution at a volume that wets the foliage but not to the point of runoff. Both applications are most effective between late June and early October, as long as the mimosa tree is actively growing and not under drought stress.

A cut-stump treatment using undiluted Capstone also has proven effective in controlling mimosa tree. Cut the target stem as close to the ground line as possible and immediately treat the top of the stump around the cambium layer close to the edge of the stem with the product. Apply a liberal amount of spray to the cut surface but not to the point of runoff.

Depending on the level of infestation, elimination of mimosa tree requires follow-up treatments for at least two years. The establishment of desirable vegetation, such as native trees and grasses, will help to discourage new seedlings.