The weeping willow is a rapidly growing deciduous tree often found alongside bodies of water. This water-loving tree produces dense, rich-green foliage that falls into a symmetrical, but weeping canopy. The weeping willow is susceptible to many of Georgia's tree diseases.
Placement is an important factor in reducing, if not preventing, disease of the weeping willow. This willow must be planted in a well-drained location that provides ample room for its growth. Although the weeping willow is a water-loving tree, it has a high drought tolerance and thrives easily in all types of well-drained soil environments. This rapidly-growing tree has an aggressive root system. The University of Florida Extension explains that the roots of the weeping willow can spread approximately three times larger than the tree's canopy. The weeping willow also requires full sunlight for healthy, successful growth. The failure to provide the weeping willow tree with a sunny, well-drained location with lots of growing room will stress the tree and increase its potential for disease.
Crown gall is a common disease found in Georgia's weeping willows, as well as other Georgia trees. This bacterial disease infects the weeping willow through natural and man-made wounds that appear on the trunks and branches of the tree. The disease attacks the cells near, and within, the tree's vascular system, which causes the distortion and decay of those cells. Crown gall disease also infects the root system of the weeping willow, causing the development of bacterial galls on the roots of the tree. Galls may also appear near the graft union line, as well as on branches and twigs. The resulting infection and appearance of galls causes stunted growth and dieback. Although crown gall cannot be eliminated once it infects the weeping willow, infections can be prevented with a chemical treatment.
Georgia's combination of cool, damp spring months and hot, dry summer months make powdery mildew a common disease amongst the area's weeping willow trees. This fungal disease attacks the foliage of the willow tree with microscopic fungal spores. These spores infect the foliage during the spring months and germinate during the dry, humid summer months. The infected foliage of the weeping willow develop powdery white fungal coverings that cover small necrotic spots on the leaves. Powdery mildew is not a detrimental disease of the weeping willow tree when the disease is addressed in a timely fashion. This disease is easily treated with a combination of fungicidal sprays and pruning of the infected areas.
Along with crown gall and powdery mildew, the weeping willow tree is susceptible to other common diseases that are prevalent in Georgia. These diseases include tar spot, black canker, leaf spot, rust, blight and various rot diseases. Although these diseases have varying effects on the tree, most of these diseases can be detrimental to the weeping willow when left untreated.
Control and Prevention
Prevention is always the most effective control of disease. Weeping willow tree diseases can be controlled by maintaining an effective irrigation and pruning schedule. In addition, schedule regular fungicidal spray treatments to reduce the potential of infection. To ensure that your treatments are effective, speak with a local nursery or horticultural specialist for assistance.