Mimosa acacias are more commonly called "silver wattles." The scientific name for this evergreen shrub or tree, which is native to Australia, is Acacia dealbata. This plant is commonly seen in California, where it has become naturalized and is considered an invasive plant, according to the Calflora website.
Mimosa acacias are most distinctive for their bright yellow, rounded flowers that appear much like sunny cotton balls perched on the tips of twigs. The leaves, which are grayish-green in color, are heavily segmented and appear almost fern-like in form. This tree will reach a mature height of 90 feet at the most, but many remain much shorter or even shrub-like in form, with multiple trunks.
Silver wattle trees are fast-growing, according to the DAISIES (Delivering Alien Invasive Species Inventories for Europe) website. They prefer warm climates with little or no exposure to freezing temperatures, which is defined as U.S. Department of Agriculture growing zones 8 through 11. A. dealbata can tolerate freezing temperatures more readily than most of the other species.
Mimosa acacias grow best in full sunlight, according to the Gardening EU website. Find a place for your A. dealbata that is open enough for it to be exposed to a full day's worth of sun. Well-draining soil is vital, or the plant may develop root rot, a fungal disease caused by overly wet soil. Once established, these small trees or shrubs are drought-tolerant.
Every part of acacia plants have been used by people groups in the past, according to the Australian National Botanic Gardens. Boomerangs and weapons were made from the wood of these trees. Today, tannin is often extracted from the bark of A. dealbata and used in tanning. The silver wattle is also used as an ornamental landscape tree, especially by home gardeners who want a stunning, spring display of yellow blossoms to complement other early-blooming flowers, such as daffodils.
Mimosa trees have weak wood. The branches tend to become brittle and can easily break in windstorms. They are also vulnerable to boring insects, which can further weaken the wood and carry fungi or bacteria into the tree. These trees do not have a long lifespan and will usually live only 20 to 30 years at the most.