Pros and Cons of Planting Mimosa in Your Yard

Albizia julibrissin, also called silk tree, was introduced into North America from China where it is a native species. The tree along with its silk-like flower arrived in North America in 1745 and was rapidly planted and cultivated for use as an ornamental. Mimosa is still planted as an ornamental because of its fragrant and showy flowers, but has since escaped into the forest and is now considered an invasive exotic. Mimosa's ability to grow and reproduce along roadways and disturbed areas and to establish after escaping from cultivation is a major problem. Mimosa is considered an invasive tree in North America.

The Beautiful Mimosa Flower and Leaf

The mimosa has showy and fragrant pink flowers that are just over an inch long. These lovely pink flowers resemble pompoms, all of which are arranged in panicles (loose branching clusters) at the ends of branches. These beautiful flowers appear in abundance from late April to early July creating a spectacular sight that enhances its popularity.

These flowers are the perfect color pink, almost flamingo-like in hue. They have a pleasant fragrance and are very attractive during spring and summer flowering, sometimes described as looking like cotton candy, starbursts, or fireworks. Hummingbirds are attracted to the flowers, as well as other pollinators such as bees and butterflies. Despite their beauty, the flowers can also be a mess on the property under the tree.

The abundant fern-like leaf also adds a bit of magic and is unlike many, if any, of the North American native trees. These unique leaves make Mimosa popular to use as a terrace or patio tree for its light-filtering effect with "dappled shade and a tropical effect." Its deciduous nature (meaning, it loses its leaves when dormant) allows the sun to warm during cold winters. These leaves are finely divided, 5 to 8 inches long by about 3 to 4 inches wide, and alternate along the stems.

It is also exceptionally fast-growing, gaining as much as five feet in a single growing season. The mimosa is considered a small- to medium-sized ornamental tree, and it can reach a height of 20 to 25 feet overall and attain a width of 10 to 20 feet.

Growing Mimosa

Mimosa grows best in full sun locations and is not limited to any particular soil type. It does have a low tolerance for salt and grows well in acid or alkaline soil. Mimosa is drought-tolerant and can resist periods of low rainfall, but it will have a deeper green color and more lush appearance when given adequate moisture. It prefers USDA Hardiness Zones 6 through 10.

The tree lives on dry-to-wet sites and tends to spread along stream banks. It prefers open conditions but can persist in the shade. You will seldom find the tree in forests with full canopy cover, or at higher elevations where cold hardiness is a limiting factor. 

Why You Should Not Plant Mimosa

Mimosa is short-lived and very messy. In a very short time, it fills out and shades large areas in the landscape while inhibiting other sun-loving shrubs and grasses. Seed pods litter both the tree and the ground, requiring regular cleanup.

The seeds readily germinate and seedlings can cover your lawn and the surrounding area, which you'll then have to weed out. The mimosa flower is admittedly beautiful, but if the tree is shading outside property or over automobiles, you will have a major annual cleaning problem through the flowering season.

The wood of mimosa is very brittle and weak and the multiple spreading branches are prone to breakage. This breakage is a major factor in its limited ability to live a long life. In addition to the breakage, the tree attracts webworm and vascular wilt, which lead to an early demise.

Typically, most of the root system grows from only two or three large-diameter roots originating at the base of the trunk. These can raise walks and patios as they grow in diameter and make for poor transplanting success as the tree grows larger. If numerous trees are allowed to sprout and grow up, they can form dense thickets that prevent other plants from growing properly.