Dogwood Tree Leaves Brown Spots
In addition to spot anthracnose a second anthracnose disease called dogwood anthracnose caused by the fungal pathogen discula destructiva can attack dogwood.
Dogwood tree leaves brown spots. Tiny dark brown fungal fruiting structures dot the brown areas. This disease is caused by the fungus elsinoe corni one of the most common leaf diseases of flowering dogwoods. The flower bracts are usually attacked first and then the leaves young shoots and fruit of dogwoods primarily during wet spring weather. Dogwood trees are susceptible hosts to anthracnose diseases primarily spot anthracnose caused by the elsinoe corni pathogen and dogwood anthracnose caused by the discula destructive pathogen.
Also large brown blotches of dead tissue may occur on leaf tips along the margin of leaves or between the veins. The infection is manifested in the form of leaf spots and stem cankers. Powdery mildew can occur yearly. The shoots are also killed in this disease.
Three leaf spot diseases that show themselves in varying degrees are dogwood anthracnose spot anthracnose and powdery mildew. Blight begins with small brown centered gray spots that appear on leaf surfaces and distort leaf growth. This disease infects leaves starting. When leaves are falling off dogwood in summer it could mean a serious illness improper siting or cultivation problems.
Small reddish brown spots without brown centers may pepper portions of the leaf or extend along veins. Dogwood anthracnose and powdery mildew are of particular concern. There are any number of diseases and pests that can stress your dogwood and cause dogwood leaf drop. These diseases are fungi that prosper in cool wet weather and infect leaves as soon as they open in spring.
Ascochyta cornicola is a fungus that appears on dogwood foliage after unusually rainy springs attacking new leaves as they emerge. One of the very common diseases of dogwood trees is the dogwood anthracnose which is caused by the fungus discula sp. Brown spots up to 1 4 inch in diameter go entirely through the leaf and have reddish brown halos. Dogwood anthracnose was confirmed in st.
Louis in 2012 and again in 2015. Ornamental dogwoods are prone to several leaf spot diseases but the fungus septoria is commonly found in indiana. When a dogwood tree does not receive adequate water the leaves of the tree begin to dry with the. It is normal to see leaves falling in autumn but you should not see a dogwood tree dropping leaves in summer.
It causes angular brown lesions bordered by a purplish color on the leaf. The leaf spot symptoms are similar to dogwood anthracnose however septoria does not infect the twigs or branches so it is a much less damaging disease.