Mimosa Trees: Beautiful, Exotic, Aromatic -- and Threatening?
Mimosa Trees Are Originally from Asia
The mimosa tree, sometimes called the Persian silk tree, is a legume and can help enrich the soil where it grows. The Persian name means “night sleeper,” and in Japan it is known as the sleeping tree. That is because the bipinnate leaves fold up at night and during rainstorms.
Bipinnate simply means that instead of one undivided leaf, the leaves are separated like those of a fern or a palm frond. The flowers are anywhere from pale to deep pink and form in clusters that look like fine silk threads. They form long pods 5-7 inches long that enclose the seeds.
The technical name, Albizia julibrissin, is native to eastern and southwestern Asia, but does well in most climates here in the states. It is a fast growing ornamental tree that can reach up to 30 feet or slightly more in height.
Clouds of Profuse Soft Pink Blossoms
Hummingbirds, butterflies, deer, birds and bees, all love mimosa trees. They smell wonderful, and they are my favorite trees in Texas, the first place I am aware of having seen them. I always look forward to their blossoms that usually appear in late spring and last for several weeks.
Some of the places where I have lived in Texas have had mimosa trees right near my front door. One evening about dusk, I was going out to run an errand, and I just happened to look up for some reason. There seemed to be a fairytale like cloud of pink cotton candy above me due to the folding of the mimosa tree’s leaves, making them invisible in the low light. The limited light made the feathery blossoms appear like soft fluff suspended in the air, and the smell was intoxicating.
That vision of the blossoms on the mimosa tree that I saw for the first time in my life that evening has remained with me. That was when I first learned that the leaves of the mimosa fold for the night. I often wish I could have gotten a photo, but it probably would not have turned out well in such low light anyway.
Some Advantages and Disadvantages Of the Mimosa Tree
The mimosa tree is cold weather tolerant and has been known to survive temperatures as cold as -25 degrees Fahrenheit. Nature Hills Nursery in Omaha Nebraska claims the mimosa tree “acts as a natural de-wormer for woodland creatures.”
From my own experience, in addition to being pretty and smelling wonderful, the mimosa trees that have been in my yard provided lots of great shade from the sun.
Unfortunately, the mimosa tree is considered by many horticulturalists, and others, to be an ecological threat. Mimosa trees can grow in a variety of soils, produce large seed crops that travel and spread easily by wind and water, and re-sprout when damaged.
The mimosa, I am told, 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. I must confess, that as prevalent as mimosa trees are here in North Texas, I have never seen a "dense stand" of them anywhere, nor have they ever gotten out of control that I know of. I have never heard anyone complain about them.
The seedpods are poisonous at all times and the seeds within even more so. Do not allow livestock, pets, or especially children to put the seedpods or seeds in their mouths. They can cause seizures and even death.
Be sure to keep the seed pods away from animals and children. Rake them up as soon as they begin to fall and teach your little ones and all of your children never to put the seedpods in their mouths. Do not assume an older child, or even an adult who may be unfamiliar with mimosa trees knows not to do so.
The flowers and leaves are not toxic and some people cook them and eat them like vegetables or make tea from them, but avoid the seedpods and seeds (John Minton, Gardens of Tomorrow).
Mimosa Strigillosa, Not a Tree, but a Ground Cover
It has come to my attention that there is a good deal of confusion regarding mimosa. Some information states that the seedpods are often used as livestock feed while other information says the seedpods and seeds are the most noxious part of the plant, and can at the extreme cause death.
For that reason I am including information about mimosa strigillosa, also called powderpuff mimosa (because of its soft flowers), and also called sunshine mimosa (it prefers full sun but can do quite well in shade).
Mimosa strigillosa or mimosa powderpuff is a ground cover and is indeed used as food for livestock such as cattle and chickens or turkeys, and is equally utilized by wild fowl, deer, caterpillars, and honeybees. No part of this strain of mimosa was listed as toxic, and its parts are regularly utilized as food by both domestic livestock and wild animals.
I am including photographs of this type of mimosa so that my readers may learn to recognize it. It does not grow into trees or bushes and remains fairly close to the ground, usually 3 to 4 inches high, but rarely as much as 12 inches high. The USDA (United States Department of Agriculture) says it is not considered an ecological threat or in any way invasive, yet the University of Florida Lee County Extension office says it “is difficult to control in restricted areas and is best grown with definite boundaries, such as pavement or sidewalks, where it can be more easily edged.”
Mimosa Strigillosa is a very hardy plant, and can withstand many severe conditions. Like the mimosa trees, this ground cover readily adapts to most soil types and can withstand drought very well. While it does grow well from the seeds it produces, the stems also spread and form an overlapping vegetative mat making it an excellent way of controlling erosion.
Please see my list of references below, and by all means check them out for more information on this plant and any questions you may have about it. Whenever you have questions about plants, gardening, lawn care, animals either domestic or wild, pesticides or other chemicals, food, food additives or preservatives, recipes, or a huge variety of different issues and subjects relating to plants or animals, consult your local county agricultural extension office, a free service provided by tax dollars. Every state and most counties have one.
U.S. Dept. of Agriculture
University of Florida Lee County Extension
Mimosa strigillosa or mimosa powderpuff
© 2012 C E Clark