Strawberry trees (Arbutus unedo) are attractive, evergreen landscaping trees whose fruits often attract birds. They are resistant to most diseases but may occasionally become infected.
Some diseases will cause only cosmetic problems in strawberry trees. Sudden oak death, while fatal to oak trees, will cause only leaf spots or twig dieback in strawberry tree. Leaf gall, caused by the Exobasidium vaccinii fungus, causes leaves to become crisp, distorted and thick. Tar spot, a type of leaf spot disease, will cause brown spots on leaves. Severely infected trees may lose their leaves, but the tree won't be seriously harmed.
Annosus root disease, caused by a fungus, will infect the roots of the tree causing conks to appear around the root crown and bark to readily separate from wood in infected areas. It can kill the tree. Canker diseases can kill the tree or branches by girdling them. Crown or root rot will kill the tree. It may slowly die over a few years, or it may be killed in one season.
Control leaf gall and tar spot by keeping leaves as dry as possible, removing fallen leaves immediately and removing infected leaves, which also helps control sudden oak death. Annosus root disease will infect wounded areas, so try not to injure the tree. Keep plants healthy and remove dead leaves and branches beyond the point of the cankers, unless the trunk becomes infected. Ensure the tree has good drainage and isn't planted too deeply to prevent crown or root rot.