Palm trees are evergreen plants in the palmaceae family. They’re prized by home gardeners for their large, attractive leaves and generally low maintenance. While healthy palm trees don’t typically pose a falling risk in your landscape without being cut or pushed by tremendous force, there are ways in which your palm trees roots or trunk can become weak, which leads to a toppling tree.
Sudden crown drop is a disease that is usually caused by the fungus Thielaviopsis paradoxa, although it has not been confirmed that this pathogen is the primary cause of sudden crown drop. This disease causes internal decay of the trunk that is not visible from the outside. The pseudo bark appears healthy, as do the leaves, but this small amount of healthy tissue is not enough to support the weight of the trunk. Eventually the decay causes a palm trees entire crown and the upper portion of the trunk to fall. The upper portion of tall palm trees can weigh several tons. Cultural factors such as drought stress can promote development of this disease, as well as injury caused by pruning, which provides a point of entry for the pathogen. There is currently no fungicide treatment available to prevent or treat sudden crown drop, and an infected tree cannot be saved.The giant palm borer (Dinapate wright) is a black to brown beetle that can weaken palm trees internally. Its yellowish-colored larvae live within palm trunks, requiring several years to mature. Both the adults and the larvae tunnel into the trunk wood, leaving holes as big as 1/2 inch in diameter. Borer infestations cause fronds to turn yellow and can lead to plant death. Because the tunnels weaken your palm tree, a strong wind can cause limbs or even entire portions of the trunk to fall over. Giant palm borers are believed to be a secondary pest attacking already dying trees, so providing good growing conditions and proper care my prevent infestations.Palm tree roots that are planted too shallow may grow above soil level and do not have a stable base to support the weight of the tree. Roots that are planted too deep may suffer from nutritional deficiencies and water stress. This can cause your palm to lose much of its root system, making it unable to support its own weight. Transplanted palms should always be planted so that the root ball is at the same depth as the previous location. The only exception is when the roots of the tree are exposed or you’re transplanting a tree that has toppled over. In these situations, plant your tree so that the top of the root ball is about 1/2 to 1 inch below the surface of the soil.