Anthracnose is a very common disease that attacks a very wide range of plants and trees. There are two ways Anthracnose disease can attack trees: 1) Spot Anthracnose that impacts tree leaves and blossoms, and; 2) the more harmful canker versions that disrupt a tree’s vascular system.

When Spot Anthracnose initially emerges, small light brown spots of dead tissue emerge on the leaves and blossoms in the late spring and summer. The spots develop during the cool, wet humid spring weather. Often the brown dieback is located along the leaf’s vein system.

The disease is caused by a fungus that over-winters on the bark of the tree or on fallen leaves. In the spring, the fungus is spread by rain and wind, which transports the fungus to newly developing healthy leaves and blossoms. When the tree is severely infected over several seasons the fungus will infect and kill branches.

If a tree is infected with Anthracnose over several seasons, the fungal disease can begin to infect twigs and branches. Once the tree’s vascular system becomes infected with Anthracnose, the tree’s bark will begin to show symptoms. Dark colored lesions or indents can begin to show on branches and twigs. Cankers can develop and branches show dieback. As the tree is stressed, it is common to see small saplings begin to sprout from the base of the tree’s trunk. 

Recommend Steps to Control Anthracnose (Leaf and Blossom Infections)

Promote the overall health of the tree with regular proper fertilizing, using the TreeHelp Annual Care Kit. If a tree has been infected spray it with the Fungi Max Multi-Purpose Fungicide. Repeat as necessary. To reduce or prevent reoccurrence the following year, in the fall, spray the tree and surrounding area with the Fungi Max Multi-Purpose Fungicide to reduce the number of over-wintering spores. Also be sure to remove and destroy any fallen leaves.

Recommended Steps to Control Anthracnose in the Tree’s Vascular System

When a tree’s vascular system is infected with Anthracnose, immediate steps need to be taken to arrest the disease spread. In the early spring, at the time of bud break, spray the tree with Fungi Max Multi-Purpose Fungicide. Continue spraying the tree with the fungicide every week until the leaves are fully developed. Once the leaves are fully developed spray the tree every 3 to 4 weeks until the end of the season. To enhance the effectiveness of the Fungi Max Multi-Purpose Fungicide, mix the spray with Nature’s Own Helper spray additive.

If the tree is too tall to spray, treat with the Garden Fos with Pentra-Bark.

In addition to treating the tree with the appropriate fungicide, prune and destroy dead and severely diseased branches. Be sure to prune during dry weather and sanitize the pruning tools after each cut with a mixture of 1 part bleach and 4 parts water.