The willow acacia tree is a species of acacia that belongs to the plant family, Fabaceae. Though this tree is called willow acacia, it is actually not a true willow. It is called willow basically for its weeping appearance. It is a medium-sized, thornless tree, native to Australia. It is also known as native willow, Australian willow, willow wattle, black wattle, sally wattle, and Broughton willow. The scientific name of this tree is Acacia salicina.
It is a fast growing tree with thin arching branches that hang down, just like a willow tree. This tree can grow up to a height of 40 feet. A mature tree can be 15 to 20 feet wide. The estimated rate of growth is about 25 inches per year, according to the Urban Forestry Program in Tucson, Arizona.
Willow acacia is an evergreen tree with narrow and long foliage. The leaves are usually dark green in color, but can also be blue-green at times. The bark of the young tree is smooth, but can gradually develop fissures as the tree matures.
The tree produces fragrant and creamy white-colored, puffball flowers. Some trees can also produce yellow flowers. The flowers can become quite abundant in spring. The usual blooming time is late summer to early winter. The flowers of this tree are however, not very attractive. The blooming period is soon followed by the appearance of narrow seed pods, which mature between September to November. The seeds of this tree are edible. In fact, the seed pods and leaves of the tree are used as fodder for livestock.
Care and Maintenance
It is a low maintenance tree, which means that it does not require much care. The tree grows quite rapidly, if it gets the right growing conditions. It grows well in full sun. The USDA hardiness zone for this tree is 8 to 11. The willow acacia tree can tolerate drought, and hence it requires only minimum watering. Once the tree establishes itself to the ground, it needs to be watered once in every three or four weeks during the summer days. During winter, the frequency of watering can be reduced to once in every two months. Usually, deep irrigation is recommended for this tree, as it promotes the development of a strong and extensive root system.
Due to its minimal water requirements, this tree is widely used for landscaping in dry areas. Moreover, it can adapt to a wide range of soil types, provided the soil is well-drained. It can be grown in loam, clay, as well as sandy soil. The tree usually does not require much fertilization. To maintain the characteristic weeping look of the tree, it is important to thin the foliage at regular intervals. Usually, light pruning is recommended for this tree. While pruning, it is essential to remove the dead, broken, and the diseased branches to promote air circulation and maintain the look of this tree.
Willow acacia is one of the hardiest and low maintenance trees available for landscaping. The tree can however, become susceptible to pests like desert mistletoe and caterpillars. Another problem is that, the branches can be a bit brittle and they may fail to resist wind. But unlike many other trees, this tree presents only a few problems.