Fact Sheets

Maple: Anthracnose

Maple: Anthracnose categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-25 10:14 Maple anthracnosePhoto by: R.S. Byther Biology Maple anthracnose is a fungal disease affecting leaves and sometimes twigs. Infected leaves develop discrete brown spots and/or blotches, often at leaf tips and often associated with the main or secondary veins. Japanese maples tend to […]

Maple: Bacterial leaf spot and dieback

Maple: Bacterial leaf spot and dieback categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-12-05 12:00 Pseudomonas leaf spot on maplePhoto by: R.S. Byther Biology Bacterial leaf spot and dieback is caused by the same bacterium which causes bacterial blight of lilacs and many other woody ornamentals. Symptoms include leaf spots, blackening of leaf […]

Maple: Fasciation

Maple: Fasciation categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-25 10:01 Fasciation showing a flattened, twisted, ribbed stemPhoto by: R.S. Byther Biology Fasciation is a plant deformity which results in abnormally flattened stems. It is the result of a mutation in the growing point of the stem and is not a disease. Instead […]

Maple: Leaf scorch

Maple: Leaf scorch categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-25 09:57 Leaf scorch on maplePhoto by: R.S. Byther Biology Leaf scorch on maple has many possible causes. Plants that are under stress, such as drought or heat stress, may not provide sufficient water to the leaf margins, causing the edges of the […]

Maple: Nectria canker

Maple: Nectria canker categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-25 09:54 Tubercularia canker fruiting bodiesPhoto by: R.S. Byther Biology Nectria is a fungal infection which often attacks via wounds and forms cankers on twigs, branches, and trunks. The cankers are often sunken areas that develop conspicuous yellow to orange-red fungal fruiting bodies […]

Maple: Phyllosticta leaf spot

Maple: Phyllosticta leaf spot categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-25 09:50 Biology Symptoms of Phyllosticta leaf spot on many maple species include the development of small (approximately 1/5 inch), roughly circular, brown spots with dark reddish or purplish borders. Japanese maples develop yellowish or tan spots, which sometimes have transparent centers. […]

Maple: Powdery mildew

Maple: Powdery mildew categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-25 09:26 Powdery mildew on maplePhoto by: R.S. Byther Biology Powdery mildew of maple is a fungal disease which affects many hardwoods including maple, hazel, birch, and alder. On maples, a characteristic white, fuzzy or powdery growth appears on the upper or lower […]

Maple: Tar spots

Maple: Tar spots categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-24 10:36 Maple tar spotPhoto by: R.S. Byther Biology Tar spots are caused by a fungal infection that commonly attacks bigleaf maples and occasionally other species. In late spring to early summer, leaves develop small areas that appear water-soaked. The areas develop small, […]

Maple: Verticillium wilt

Maple: Verticillium wilt categories: Maple Maple Diseases Ornamental trees Ornamentals revision date: 2022-11-23 05:12 Verticillium wilt on small maplePhoto by: R.S. Byther Biology Verticillium wilt is caused by a soilborne fungus. It infects plants via the roots and then spreads throughout the plant. Symptoms on the aboveground portion on the plant include suddenly wilted yellow […]