Commonly known as the mimosa tree or silk tree, Albizia julibrissin is an attractive yet invasive tree that is threatening Florida’s landscape.
Originally from China, the mimosa tree has been a popular landscape tree in Florida for many years because of its fragrant pink flowers and feathery, fern-like foliage. The delicate, puffy flowers bloom from late April to early July.
While these trees started out as landscape plants, they have escaped cultivation and have moved into natural areas where they compete with native vegetation. Mimosa trees will grow in a variety of soil types and take advantage of sunny areas, growing up to twenty-five feet tall. Mimosas produce large amounts of seed pods containing five or more small brown seeds which typically persist on the plant though the winter. Seeds, which can remain dormant for years, are normally dispersed in close proximity to the parent plant; however, they can be spread by water or wildlife. They can become a serious problem along rivers, where their seeds can be easily transported.
Due to its ability to grow and reproduce along roadways and disturbed areas, and its tendency to readily establish after escaping from cultivation, mimosa is considered an invasive plant and not recommended for any use by the IFAS Assessment.
Another drawback is mimosa wilt—a disease that is becoming a problem across the county and is responsible for killing many roadside trees. Infected trees will start out with paling, drooping leaves on a single branch. As the disease progresses, leaves will turn yellow and fall off the tree. The same thing will happen with the rest of the branches on the tree until the tree dies, usually within a year of the symptoms first being observed. While this disease has helped reduce the number of mimosas in Florida, this tree is still not recommended for planting in the landscape.
The best way to get rid of a mimosa tree is to cut it down at ground level. Mimosas are able to re-sprout after being cut back so keep an eye out for new growth. To control resprouting, you’ll either have to cut off new growth or use a herbicide on the stump. Seedlings can be pulled by hand, but make sure you get all the roots. Learn how to recognize this tree and take action to prevent its spread.
The flowers of the powderpuff tree look very similar to the mimosa’s.
If you love the look of mimosa trees but want a non-invasive option, try planting sweet acacia or red bottlebrush. Sweet acacia, Acacia farnesiana, has a similar look to the invasive mimosas, sporting delicate foliage and yellow puffed flowers. Bottlebrush (Callistemon spp.) and dwarf powderpuff (Calliandra spp.) are two other plants that will give you delicate flowers that somewhat resemble those of the mimosa tree.
- UF/IFAS Assessment of Non-Native Plants in Florida Natural Areas: Albizia julibrissin
- Mimosa tree Albizia julibrissin
- Albizia julibrussin: Mimosa Tree
- Alternatives to Invasive Plants Commonly Found in North Florida Landscapes
Also on Gardening Solutions
- Sweet Acacia
Texans do complain about mimosa trees, but the complaint is about the messiness of Mimosa not its invasiveness. The tree sheds in multiple stages; blossoms, followed by seedpods, then leaves, then sticks, which are either leaf petioles or twigs. The sticky, staining, brown paste formed by wet dropped blossoms is particularly noxious. Plants underneath a Mimosa can become coated and disintegrate under a thick carpet of brown flower goop. Positioning a Mimosa over a walkway or driveway may not be prudent. Mimosa also messily self-sows all over the yard.
When growing these beautiful trees on your property, there are several important steps to consider.
First, plant mimosas in a well-draining, sunny site that provides lots of room for it to grow as it grows up to thirty feet tall and thirty feet wide. Water a newly planted mimosa when the soil is dry. Keep doing this until its roots are well established. This should take just one season. Afterwards, water the tree only during droughts. Mimosa will die in soggy soil. Mulching conserves water and increases the time between waterings.
Fertilize mimosa sparingly in spring or not at all. This tree is already a fast grower. Don’t use too much fertilizer. It speeds up growth but can result in weaker branches. Make sure you use a balanced fertilizer, such as 10-10-10. I’d recommend using it at half the rate recommended on the label.
Important note: Mimosas will, most-likely, not last a lifetime. These trees are prone to damage from disease and insects. They will probably grow quickly, reach their peak, then decline and die in about 15 years. These trees bear long seed pods that cling fast, even in winter. Mimosas seed freely, so you’re likely to find new seedlings in your lawn and garden each spring. Most important of all is that you must be mindful of mimosa seeds and seed pods as they are very poisonous. “Beautifully dangerous,” noted Mark Twain when commenting on the mimosa tree. The seedpods are poisonous at all times and the seeds within are 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. Thoroughly wash hands after handling the seed pods.
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. I have made a very nice tea from drying the flowers and leaves, but I always avoid the seedpods and seeds.
By Julie Christensen
Mimosa trees, also called Silk trees, are native to Japan and Iran. In the U.S., they are winter hardy only in U.S. Department of Agriculture plant hardiness zones 6 through 9. Even there, they are usually short-lived, succumbing to branch breakage and disease in 10 to 15 years.
From April to July, in areas with mild climates, you’ll see mimosas (Albizia julibrissin) in bloom. The white to pink blossoms have a sweet fragrance that attracts bees and their airy, cotton-like form makes them a glorious sight to behold.
Mimosas are commonly grown along fences or as patio trees. Their lacey, fern-like foliage, fast growth and open, umbrella-shaped canopy make them popular landscaping trees. Unfortunately, mimosas have a few liabilities that you should know about before planting them. Mimosas develop flat, bean-like pods from late summer to fall. These pods, along with the leaves, create quite a bit of lawn litter. The branches and twigs break easily in stormy or windy weather. Mimosas have shallow roots that grow within the top 2 feet of the soil. These shallow roots make it difficult to transplant larger mimosas. They also sometimes emerge above ground, where they damage sidewalks and patios.
In addition to a propensity for disease and insect problems, mimosas are invasive in moist, humid climates, such as Florida. The flowers float on wind or water, carrying seed great distances. Because mimosas are so adaptable, they readily self-sow in the wild, often outcompeting native vegetation. Many communities have placed bans on planting new mimosas because of their potential for invasiveness.
Despite their shortcomings, southern gardeners love mimosas. They grow best with moist, well-draining, light soil, but they tolerate both clay and sand, as well as alkaline and acidic soils. They don’t grow well in salty soils, making them a marginal plant for coastal areas.
To start a mimosa, buy a potted nursery plant, if they’re available, or start it from seed yourself. Soak the seeds in water overnight. Plant them outdoors when daytime temperatures are at least 65 degrees or sow them indoors in a light potting mix. If starting indoors, plant mimosas in peat pots to avoid root disruption when you transplant them outdoors. Plant the peat pot directly in the garden.
Plant mimosas in a sunny location for best flowering and leaf color. They tolerate and thrive in hot conditions. Water newly planted mimosas frequently to keep the soil moist 1 inch beneath the surface. Established trees can tolerate drought conditions, but they’ll perform better with reasonably moist soil. Fertilize the tree every six weeks during the growing season with a ½ cup of 10-10-10 fertilizer.
Mimosas grow 15 to 30 feet tall and 10 to 15 feet wide. Plant them so air circulates freely. Avoid planting them near patios and sidewalks to prevent damage.
Mimosa Pests and Diseases
The major pest of mimosas is the mimosa webworm, the larva of a white or gray moth. Upon emerging from their eggs, the larvae spin a web around the leaves of the trees. They then feed on the leaves, skeletonizing them and causing them to turn brown. In severe infestations, the entire tree can become defoliated by late summer.
Consider planting a different tree if you live in an area where mimosa webworms are prevalent. To control the pests, spray the trees with Bacillus thuringiensis in spring when the larvae first appear. Control is more difficult once the larvae spin webs.
Mimosa vascular wilt is a fatal disease that has destroyed countless mimosa trees throughout the southeast. This soilborne disease is sometimes spread through contaminated nursery soil. Initial symptoms include chlorosis of the leaves. The leaves yellow, while the veins remain green. Later, the leaves begin to drop, branches break and the trunk oozes a frothy liquid. Once infected, you can slow the effects of the disease by watering frequently and fertilizing with a balanced fertilizer. Avoid high nitrogen fertilizers.
For more information, visit the following links:
Albizia julibrissin (Mimosa, Silk Tree) from Fine Gardening
Albizia julibrissin from the Missouri Botanical Garden
Julie Christensen learned about gardening on her grandfather’s farm and mother’s vegetable garden in southern Idaho. Today, she lives and gardens on the high plains of Colorado. When she’s not digging in the dirt, Julie writes about food, education, parenting and gardening.
Mimosa – The Wonderful, Awful Weed
When anyone asks me what’s the best time to prune a mimosa, my instinctive response is, “Any time you can find a chainsaw.”
That’s very judgmental of me, I know, but heck, that’s pretty much my job. And mimosa is one of those plants you either love or you hate. I hate it now. But I used to love it.
Why, when I was a kid, at the nadir of sensibility and good taste, I thought mimosa (Albizia julibrissin) was the prettiest tree in the world. Its leaves were like ferns. Its flowers were pink puffballs. And it bloomed in summer, when few other trees did.
A Miracle — My Wife Agrees!
Judy, who notices very few plants, has fond childhood memories of mimosa too. She remembers climbing up in her neighbors trees to smell the flowers. I think they smell faintly of gardenias — not like my son’s socks, which would actually cause you to faint.
How It all Began
Native to the Middle East and Asia, mimosa was brought to this country in 1785 by the famous French botanist Andre Michaux, who planted it in his botanic garden in Charleston, South Carolina. It grew quickly into a vase-shaped, flat-topped tree, 30 to 40 feet tall, and it loved the Southern climate. The flowers, attractive to butterflies, hummingbirds, and colonial gardeners, ranged in color from nearly red to deep pink to flesh-pink to white. On one road-side near my home, there is a row of them, each a different color. Here’s the usual pink.
And here’s a white one. I really like the white, but I’ve never seen it for sale. The various colors are due to genetic variation, with pink being dominant. Where I live in Alabama, the trees usually start blooming in June and continue for several weeks into July.
So Why Do I Hate Mimosa Now?
Two reasons, First, like most all fast-growing trees, mimosa is notoriously short-lived, subject to many pests, and will die on you in a heartbeat. When people ask me the best way to get rid of a mimosa, I tell them to make it the focal point of their landscape and it will be gone momentarily.
Second, after the flowers fade, the tree grows hundreds of 6-inch long, bean-like, brown seedpods which hang from every branch. The seedpods persist all winter, even after the tree has dropped its leaves. Few trees look as ugly or more forlorn.
But wait! It gets worse! Each of those pods is filled with seeds and each and every one of them germinates somewhere, even in cracks in the pavement. Plant one mimosa in the yard and soon every house in the neighborhood has two or three mimosas. coming up in the fence, the middle of a bush, or by the silver propane tank.
Mimosa adapts to almost any well-drained soil, laughs at heat and drought, and does not mind if you spray-paint the trunk white, hang tires from the branches, or park your pickup on top of its roots. In hort class, we called it a “pioneer species,” because if you disturb the land, remove native vegetation, and open the tree canopy to light, it’s one of the first trees to appear. That’s why you see it growing along just about every highway and country road in the South. Northerners be glad it doesn’t like your cold winters, but with global warming, who knows how much longer you’ll be free?
Not Fooling Me
Recently, a new kind of mimosa was introduced to the gardening world, a purplish-bronze leaf selection called ‘Summer Chocolate.’ The hype over its undeniably pretty foliage and pink flowers was overwhelming. Probably many of you bought one and are enjoying it right now. But not me.
See, any mimosa that flowers is going to produce seeds and lots of them. And if a thousand seedlings come up in my yard, I don’t care if they have green leaves or purple leaves. They need to be eliminated with extreme prejudice.
So my advice about when to prune a mimosa remains the same — whenever you can find a chainsaw.
Tell Me More About the Mimosa
Okay. Here’s a little crash course. The pink “powder puffs” of mimosa flowers appear in early June throughout the South. Fernlike leaves give the tree a lacy, graceful appearance.
A common problem are mimosa webworms. Silken webs wrap clusters of leaves together. The caterpillars inside those webs eat the leaves.
The solution: If possible, prune out and destroy webbing and damaged leaves. Thoroughly spray the tree trunk with horticultural oil in early March to suffocate pupating larvae. Rake and destroy leaf debris. Replace mulch under the tree each fall. Spray the tree with Bacillus thuringiensis kurstaki (Dipel, Thuricide, Javelin). For serious infestations, spray with carbaryl (Sevin), diazinon, or malathion.
Another problem you may encounter with mimosa is wilting. Leaves yellow and droop in early to midsummer. Many drop. Tree branches die over a period of several months.
The solution is that there is no control for the soilborne disease that enters through the tree roots. Discovered in the 1930s, it has now spread throughout the South. Remove infected trees. Do not plant new mimosas in the same spot.
Trees. Think About Trees.
No matter where you live or what garden style you prefer, the first questions you should ask when developing your garden’s design are, “Where are my existing trees?” and “What new trees would I like to add and where do I want them to go?”
As your garden’s largest living element, trees have an enormous impact, both practical and aesthetic. On the practical side, they offer shade and shelter from the wind, enhancing your comfort and often considerably reducing your home’s energy consumption. As design elements, trees can frame the house, establish scale, sport colorful blooms and foliage, conceal unsightly features, or draw the eye toward attractive vistas.
Among the most important contributions trees make to a garden is to lend an air permanence. While a hollyhock may give up the ghost after a year or two, an oak can live for centuries. A stately tree that forms the centerpiece of your garden may well have been the legacy of a farsighted gardener from many years earlier.
Choosing the Right Tree
When selecting trees for your garden, ask first what you want the tree to do. Should it shade the yard? Pick a tall-growing species that develops a sizable canopy. Should it hide a neighboring property? That may call for an evergreen tree with foliage all the way to the ground. Perhaps you’d like a focal point. Look for a tree with striking flowers, foliage, bark, or form. Once you have decided on the tree’s purpose, you can narrow your selection.
The most basic distinction between trees is whether they are deciduous or evergreen. Deciduous trees sprout new leaves in spring and carry them throughout the summer. In fall, the leaves may turn brilliant colors before dropping for the winter. Evergreen trees, on the other hand, retain their foliage year-round, making them ideal for screens or as points of interest during winter months. Broad-leafed evergreens, such as Southern magnolias and hollies, have wide leaves similar to many deciduous trees. Needle-leafed evergreens, such as pines and cedars, sport narrow, needlelike leaves.
Once you’ve decided between deciduous or evergreen, consider the tree’s growth rate and ultimate size. A desire for quick shade or instant privacy may tempt you to buy a fast-growing species such as silver maple or cottonwood, but such a vigorous tree can crack sidewalks, invade water lines, or quickly overwhelm the house, calling for replacement at a later date.
Consider, too, a tree’s mature shape (above)*referring to illustration*, which may not be obvious when you buy a small sapling at the nursery. A vase-shaped type, such as a Japanese zelkova, makes a good choice for a lawn or street tree, because its ascending branches leave plenty of headroom underneath. Rounded, spreading trees, such as live oaks and Norway maples, need lots of space to extend their branches. Columnar or conical trees, such as eastern red cedar and Arizona cypress, work well in closer quarters.
Many trees offer a spectacular burst of color in the fall, but consider their summer and winter foliage tones as well. Deciduous trees with golden, bronze, red, or bluish summer foliage should be treated as accents and used sparingly to avoid a jumble of colors. Likewise, use caution when selecting evergreens with colored foliage, such as many cedars and cypresses.
CARING FOR TREES (each section has an accompanying illustration)
Limbing up. Gradually removing a tree’s lower branches reveals the structure of the tree. This practice also increases the amount of sunlight reaching the ground, making it easier to grow grass and flowers around the tree. And it gives more headroom under the tree’s canopy. As a general rule, don’t limb up more than half of a tree’s height, less if possible.
Thinning. Selectively thin the branches of a shade tree to reduce the likelihood of wind damage, open up views, and prevent the tree from forming an overly dense canopy. Remove weak limbs and vertical water sprouts first, and any branches that rub or cross each other. Clear out branches growing toward the center of the tree. Then you can prune selectively along the main limbs, leaving a natural-looking, broad, and bushy top.
Preserving the roots. To keep a tree healthy, start at the bottom. If you build a patio or walkway around the base of a tree, avoid solid materials such as concrete, which prevent air and water from reaching the roots. Select paving that leaves as much open soil as possible around the trunk, use loose materials, or set bricks or paving stones in sand or gravel rather than cement.
If removing soil near a tree to construct a retaining wall or for some other purpose, try to preserve the existing grade around the tree by making any elevation changes beyond the branch spread. For soil-level changes over 2 feet deep, consult an arborist.
It seems obvious, but the easiest way to avoid disappointment with a tree is by selecting one well suited to your climate and soil. Don’t try to plant trees that are not reliably cold-hardy in your area or those that need more rainfall than you receive. Sooner or later Mother Nature will get even, and the trees will suffer from cold or drought stress, making them more susceptible to pests and diseases.
Other trees to avoid include those that are prone to pests; those with weak wood that can lose limbs in storms; those that drop messy fruit, seedlings (such as chinaberry above)*in picture*, or more leaves than you are willing to rake; and those with invasive roots. In addition to the trees listed at right *below*, your local nursery or garden center should be able to advise you on trees that are problematic in your region.
Ten Troublesome Trees
Think twice (or even thrice) about planting the following:
Arizona Ash (Fraxinus velutina)
Weak wood; invasive roots
Black Cherry (Prunus serotina)
Messy fruit; pest-prone
Box Elder (Acer negundo)
Lots of seedlings; pest-prone
Camphor Tree (Cinnamomum camphora)
Messy seeds; weak wood
Chinaberry (Melia azedarach)
Messy fruit; lots of seedlings
Eastern Cottonwood (Populus deltoides)
Weak wood; invasive roots
Hybrid Poplar (Populus)
Mimosa (Albizia julibrissin)
Pest-prone; lots of seedlings
Silver Maple (Acer saccharinum)
Weak wood; invasive roots
White Mulberry (Morus alba)
Messy Fruit; lots of seedlings
Why Not Top?
Topping — reducing the height of a mature tree by lopping off its top limbs — is the quickest way to ruin a tree forever. What’s more, it doesn’t even reduce the height of a tree for very long. Unlike a bushy hedge that soon sprouts new growth after being sheared severely, an older tree does not grow back in a natural-looking way when the trunk leaders or top branches are pruned to stubs. Instead, the tree sends out scores of weak shoots from the cutoff points; often these shoots are taller, coarser and denser than the natural top. Topped trees often develop heart rot, eventually resulting in hollow trunks. This makes them susceptible to storm damage.
Some topped trees might eventually regain their beauty, but the recovery can take decades. A good professional arborist will not top a tree, but will try other techniques to scale it back.
Mimosa Tree – Treasure or Trash ?
(Editor’s Note: This article was originally published on November 25, 2007. It is being repeated this week as we continue our invasive species contest. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
The Mimosa Controversy
Towards fall, I noticed long brown seedpods. Traveling by car one day, I pulled off the road and scavenged a few of the pods. I planted a seed in a pot in early spring and was pleased when it grew into a fine young tree. The tree traveled with me when I moved down to north Florida and was planted in my yard. Only later did I find out that my tree was somewhat controversial. Looking up the plant in the Dave’s Garden PlantFiles, I found that I was cultivating the mimosa tree (Silk Tree, Pink Siris or Albizia julibrissin). This tree is one of the “Top Ten Plants” at Dave’s Garden. It’s either an “invasive exotic species” or a “treasured garden heirloom” depending on one’s point of view. And people have strong points of view regarding Mimosa!! We gardeners are clearly conflicted in our approach to invasive plants.
Mimosa, Invasive Exotic
Introduced to this continent as an ornamental about 250 years ago, has established itself across much of the eastern US. As do most invasive plants, it reproduces prolifically. Numerous long brown flat seedpods are produced at summer’s end and seeds sprout with ease. Additionally, the seeds are tough and can remain dormant for decades. Although most people know Mimosa tree from the edge of the highway or train track, apparently, it also enjoys the edges of forest and streams. The narrow strips of land bordering streams are apparently a crucial component of the ecosystem; providing key wildlife habitat, controlling flooding and erosion. Dense stands of mimosa reduce the sunlight available for native species, leading to deterioration in the plant diversity in these areas and degrading wildlife habitat. Mimosa tree has made it to the “least wanted list” of several agencies tracking invasive plants.
But It’s So Pretty !
|However, the mimosa tree (pictured left)i s a lovely plant with delicate fern like foliage . It grows rapidly and could quickly provide a screen or shade. The tree is not fussy about soil pH or fertility. Many people have fond childhood memories of the Mimosa tree, often reminiscing about the entertaining play with seedpods and the lovely scent of the pom-pom like pink blooms. Mimosa blossoms also attract butterfly and hummingbirds. As an additional temptation, a stunning bronze foliaged version is available.|
Does My One Tree Really Make A Difference?
|I generally like nature and don’t really want to contribute to habitat degradation. Should I worry about my one mimosa tree when these trees are already all well established across the country? If this tree is such a problem, why are they available for sale at nurseries and on-line? I even noticed a specimen growing in the public gardens on the Mall in Washington, DC (pictured left). To add to the confusion, some municipalities restrict its use, while some have on their list of approved street trees! In most places owning this plant is not illegal and we are left to evaluate the appropriateness of this tree as a landscape plant for our individual yards.|
||Many people complain about the messiness of Mimosa (pictured left). The tree sheds in multiple stages; blossoms, followed by seedpods, then leaves, then sticks, which are either leaf petioles or twigs. The sticky, staining, brown paste formed by wet dropped blossoms is particularly noxious. Plants underneath a Mimosa can become coated and disintegrate under a thick carpet of brown flower goop. Positioning a Mimosa over a walkway or driveway may not be prudent. Mimosa also messily self-sows all over the yard. I am already constantly pulling Sable Palms, Loquats, Podocarpus and Carolina cherry seedlings out of the yard. Do I really want to confront a legion of mimosa babies as well?|
Just as many people overlook the mess for the mimosa’s scent. I can understand sparing an otherwise irritating plant due to scent. I suffer the annoyance of my gardenia’s thrips and the unattractive periodic yellowing of its leaves just to enjoy the scent of its blooms for a few weeks each year. However, I have sampled many different trees and, sadly, I can’t detect Mimosa scent. Why not sniff a mimosa next summer and see where you stand?
|I have occasionally encountered a truly magnificent full-grown specimen of this tree. However, most specimens I see in costal north Florida are small, often lichen-covered and yellowed. Mimosa does particularly poorly as an isolated lawn specimen in my area. Many of these shabby coastal specimens probably reflect poor salt tolerance. The tree is reputed to be weak wooded and our violent summer storms may prune out larger specimens. Likely, many of our local trees are affected by Mimosa wilt. This disease is caused by the soil-borne fungus Fusarium oxysporum var. perniciosum, which invades trees through the root system. Orange to pinkish fruiting bodies may show on the surface of a terminal tree ready to disperse spores to the next victim. Even if the tree survives environmental challenges, they live only for 15 to 20 years.|
The Deciding Factor
|My mimosa made seed pods (pictured left) for the first time this year. They gave me visions of crawling under the azaleas pulling sprouts. I worried about nearby natural areas. Though conflicted about taking out one of my plant babies, I am removing the Mimosa. Replacement candidates include a blue/purple flowered Vitex (Vitex agnus-castus ‘Shoal Creek’) or a native Easterm redbud (Cersis canadensis). I will miss my Mimosa but hopefully can find a better behaved tree to grow from a seed.|