The Mimosa tree (Albrizia julibrissin), also known as Persian silk tree or pink silk tree, is a small ornamental tree that was brought to the United States from China in the 1700s. The fern-like leaves fold up at night and when it rains. The pink pom-pom-like flowers attract bees, butterflies, and the occasional hummingbird. The tree is also a nitrogen-fixer in the legume family, and the nutritious seeds are sometimes fed to livestock. Interestingly, one study reported that the seeds elicited anti-depressant-like effects when consumed by mice1.

 

Unfortunately, the tree’s attractive characteristics also come with unfortunate caveats. The species’ tolerance and seed characteristics make it an aggressive pioneer species. Mimosa is tolerant of a variety of soil types, pH levels, temperatures, and water conditions. A blooming plant produces thousands of seeds that can remain dormant for decades, due to their thick seed coats. Because the plant grows quickly once it germinates, if left unmanaged, it can form dense stands that outcompete native plants for light and soil resources. When the plant sheds, its decomposing flowers form a noxious gooey substance that coats and suffocates the vegetation beneath it. The tree can reproduce vegetatively, if the trunk is cut, so eradication of an adult tree requires cutting the trunk and immediately applying a chemical spray.

 

Although the Mimosa is an attractive tree in the landscape, it is an aggressive invasive plant that overcrowds natural vegetation (and will make a mess on your lawn, driveway, and car). If you’re considering any kind of landscaping to attract wildlife and provide shade in the summertime, consider using native species instead!

--Danielle Racke

 

 

1 Kim, JH; Kim, SY; Lee, SY; Jang, CG (2007). "Antidepressant-like effects of Albizzia julibrissin in mice: Involvement of the 5-HT1A receptor system". Pharmacology, Biochemistry, and Behavior 87 (1): 41–47. doi:10.1016/j.pbb.2007.03.018.PMID 17477962.