How To Grow And Care For A Mimosa Tree

The mimosa tree is one of those plants you either love or 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.

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. Thriving in the southern climate, the plant quickly grew into a vase-shaped, flat-topped tree that reached 30 to 40 feet tall. 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 roadside near my home is a row of them, each a different color. The various colors are due to genetic variation, with pink being dominant. Where I live in Alabama, the trees usually bloom in June and continue for several weeks into July.

Beautiful mimosa trees are fast growers, provide lots of shade, and are easy to grow in a variety of conditions. Before planting, consider that they are messy trees that spread quickly and are invasive. Mimosa seedpods are toxic to dogs and livestock. Before planting, there are other options you may want to consider.

Plant Attributes

Mimosa Tree Care

Mimosa adapts to almost any well-drained soil, laughs at heat and drought, and does not mind anything you do to it. In horticulture 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. The pink "powder puffs" of mimosa flowers appear in early June throughout the South. Fernlike leaves give the tree a lacy, graceful appearance. This tree is invasive in North America because it spreads and multiplies faster than native species, preventing them from getting sun and nutrients and taking over their habitats.

Light

Mimosas prefer full sun but can tolerate some shade, especially in drier areas. They do not thrive in full shade.

Soil

Mimosas grow and do well in a variety of soil types and can adapt to poor soil conditions. They grow in acidic soil and can tolerate mildly alkaline soil, and they have a low tolerance for salt.

Water

These trees can handle drought and periods of little rainfall, but they do prefer some moisture. A young mimosa tree needs thorough weekly watering until it is established. Adequate watering as it grows gives the tree a deep green color and lush appearance.

Temperature and Humidity

While mimosa trees can withstand cold temperatures, they prefer the higher temperatures in the South. They are susceptible to frost damage during winter. Younger plants cannot survive harsh winter temperatures.

Types of Mimosa Trees

Some cultivars of mimosa are less invasive. Other varieties of mimosa that are available include:

• 'Summer Chocolate' has undeniably pretty purplish bronze foliage and pink flowers.
• 'Ishii Weeping' is a weeping variety that doesn't get too tall.
• 'Rosea' is a compact, hardy tree.
• 'Flame' has magenta flowers.

Pruning

When anyone asks me what's the best time to prune a mimosa, my instinctive response is: "any time you can find a chainsaw." Any mimosas that flower are going to produce seeds and lots of them. And if a thousand seedlings come up in my yard, I don't care what they look like, they need to be eliminated.

If you do need to prune a mimosa, do so in fall or winter after blooming and when the tree is dormant. Get rid of dead or diseased wood, and trim to keep the size and shape you want.

Propagating Mimosa Tree

Because the mimosa is an invasive tree, planting it should be limited. If you do decide to plant one, the best time to propagate is in late spring.

1. At an angle, cut from the tree a 2- to 6-inch healthy semi-ripe stem that has not bloomed.
2. Remove the lower leaves and place the cut end of the stem into a four-inch pot filled with moistened soil or peat moss.
3. Place the pot in a plastic bag, tie the top, and set it in a sunny area to maintain a temperature of about 70 degrees Fahrenheit. Keep the soil moist. Use a heat mat to spped rooting time.
4. Roots should grow in about four weeks.

How to Grow Mimosa Tree from Seed

The mimosa tree can easily be grown from seed. Harvest seeds from the tree in the fall and store them in a cool, dry place until spring. Here are the steps to grow a mimosa tree from seed:

1. Break open the dried seedpod to expose the seeds inside. Put them in a container of very hot water to soak overnight.
2. Remove the swollen seeds from the container and plant in a three-inch container with drainage holes filled with well-draining potting mix.
3. Plant the seed one inch deep and cover it with soil, and place it in a sunny outdoor location. Keep the soil moist.
4. When roots begin to show through the drainage holes, transplant the tree to its permanent location in your yard.

Overwintering

Mimosa trees prefer sunny locations and warmer temperatures, but they can tolerate cold temperatures. Plant them in a sunny area that protects them from the wind. Keep young trees protected from frost.

Common Pests & Plant Diseases

A common problem with these trees is mimosa webworms. Silken webs wrap clusters of leaves together, and the caterpillars inside those webs eat the leaves.

The solution: If possible, prune out and destroy webbing and damaged leaves. Rake and destroy leaf debris, and replace mulch under the tree each fall. Thoroughly spray the tree trunk with horticultural oil in early March to suffocate pupating larvae. You can also spray the tree with Bacillus thuringiensis kurstaki (Dipel, Thuricide, Javelin), or for serious infestations, spray with carbaryl (Sevin), diazinon, or malathion.

Another problem you may encounter with a mimosa is wilting. Leaves yellow and droop in early to mid-summer. Tree branches will die over several months.

Unfortunately, there is no control for the soilborne disease that enters through the tree roots. This disease that was discovered in the 1930s has now spread throughout the South. The only solution is to remove the infected trees and make sure not to plant new mimosas in the same spot.

Common Problems with Mimosa

There are two reasons why I think you should never buy mimosa trees. First, like most fast-growing trees, mimosa is notoriously short-lived, subject to many pests, and will die on you in a heartbeat.

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.

Each of those pods is filled with seeds, 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.

Other Trees to Consider Planting

Instead of the mimosa tree, you may want to consider an option that isn't invasive. Look for a tree that's durable in cold or harsh weather, drought-resistant, and easy to maintain. Your yard can still have beautiful blooms all summer long. Consider planting one of these options.

Chaste Tree

The chaste tree, also known as the Texas Lilac tree, produces beautiful blue-purple blooms that flower in the summer and is a good option for a cold-hardy tree that will last you a long time. In fact, I have a chaste tree that has been in my yard for over 20 years. It's a great option for smaller yards too, as it only grows 10 to 15 feet tall.

Crepe Myrtle

The crepe myrtle tree is known for its gorgeous flower clusters that bloom throughout the summer, its bright fall foliage in many cases, and its beautiful bark. This tree is very durable—it is drought-resistant and thrives in full sun, and can bloom in harsh conditions. The tree comes in pink, purple, red, and white variations.

Cherry

Cherry trees are sure to delight you with their beautiful blooms that come to life every spring, the 'Okame' variety blooming as early as Valentine's Day. There is a reason why many people crowd Macon, Georgia, each year—it's because of their enchanting rosy blossoms. These pretty-in-pink trees are also fairly easy to maintain and grow quickly when given full sun and well-drained soil.