3 Tree Diseases That Can Affect The Health Of Ash Trees


Ash trees are broad trees with thick and sometimes scaly bark. The branches are symmetrical and contain compound groupings of bright green leaves. The arrangement of the branches and leaves gives ash a distinctive look that makes the tree an interesting addition to any yard.

Keep your ash tree or trees looking healthy for years to come with some basic tree care. Tree care also includes knowing how to identify and treat some of the most common tree diseases that can strike an ash tree.

Powdery Mildew

Powdery mildew is a fungal disease that covers the ash's leaves with a grayish fuzz that can thicken to cover the entire surface of the leaves. If the leaf is entirely covered, sunlight can't cause photosynthesis and the leaf will prematurely die. Powdery mildew can make your tree start to shed some or all of its leaves in summer.

The good news is that the mildew, while unattractive, isn't posing any serious harm to the long-term health of your tree. Once the leaves start showing signs of fuzz, trim off the fuzzy leaves immediately to help minimize the spread of the disease. When new leaves start to grow in, you can apply a topical fungicide to prevent the mildew from again taking hold of the leaves.

Verticullium Wilt

Verticullium wilt is another fungus-born disease that can affect your ash tree. The disease makes the tree appear as if it is slowly dying -- or wilting. Existing leaves can yellow, brown, then fall off prematurely. Newly emerging leaves might be smaller and less plentiful than usual, which is particularly noticeable on leafy trees such as the ash. Branches can also start to show signs of wilt and eventually fall off.

Wilt can become fatal for the tree over years of infection. The chances of saving your tree depend upon the specific type of fungus that caused the wilt and your speed in handling the situation. You may want to call in a professional for a more thorough examination and treatment. The professional can test for the type of fungus and perhaps manipulate the surrounding soil in order to save the tree. Note that saving the tree isn't always possible and you should agree to a full tree removal if the tree is at risk of spreading wilt to your other trees.


Anthracnose refers to a range of tree diseases with varying symptoms that can all be traced back to a single type of fungus. The fungus that causes anthracnose in ash trees is called discula fraxinea. Symptoms include brown spots on leaves that can cause open holes that look like an insect chewed through the leaves. The leaves can start to curl and eventually fall off the tree prematurely. A sign that the dying leaves are caused by anthracnose rather than another tree disease is if the browning leaves are mostly towards the bottom of the tree. 

If you have any trouble recognizing certain symptoms, consider calling in a tree service company, such as Tree Smart Inc., for proper diagnosis. Trim away any affected leaves and keep the dead leaves off the ground around the tree. The tree should heal itself over time.


3 November 2015

Improving The Look Of Our Trees

After we moved into our house, we knew that something had to be done about our trees. The branches looked off-kilter, and we could tell that someone had pruned them incorrectly at one time or another. Unfortunately, we weren't really sure how to repair the damage. A family friend talked with us about hiring a professional tree trimmer, and so we called them the next day. The difference that they made was astounding. They removed dead branches, trimmed up the shape, and let more sunlight through. My blog is all about improving the look of your trees by hiring a professional.