Problems With Brachychiton Populneus

Texas Root Rot

• Texas root rot is a serious disease caused by a soil-borne fungus that often leads to the rapid decline and death of susceptible trees, particularly in hot climates. Texas root rot is difficult and expensive to control according to the University of Arizona, which notes that pricey chemical controls must be applied by a licensed applicator every year or two to manage the disease. The disease is better off prevented: do not plant kurrajong in areas where Texas root rot is known to be present.

Chlorosis

• Chlorosis, a yellowing of the leaves due to nutrient deficiency, may occur in soils with a pH above 8.0. Chlorosis eventually may lead to the decline of the tree if nutrients are not provided. One technique the Utah State Cooperative Extension recommends is dissolving 2 ounces of ferrous sulfate in 3 gallons of water and spraying the leaves in the evening or on a cool, cloudy day. Adding a wetting agent or a few drops of liquid soap to the mixture will help the foliar spray to stick on the leaves.

Other Problems

• The kurrajong tree produces hard, boat-shaped seed pods that are resistant to decay, causing an ongoing littler problem under the tree. Pods frequently clog reel lawn mowers and can injure barefoot pedestrians. Pods also are covered with tiny hairs that are quite irritating to the skin, making the tree difficult to propagate from seed. The tree's deep roots also occasionally make their way into drains, which can be expensive if any damage is incurred. Fruits may be toxic to some livestock.

Prevention

• Help prevent cultural problems by providing the tree with the proper conditions. Kurrajong is best suited for a bright, sunny location with deep, well draining and rocky soil in U.S. Department of Agriculture plant hardiness zones 9 to 11. Though the tree is quite drought tolerant, sapling growth can be sped up considerably with regular irrigation according to the Australian National Botanic Gardens. Plant the tree away from walkways to keep pods from injuring passersby.