Tree Diseases

Are you concerned about common tree diseases in your area? Although trees are robust and resilient creatures, every species has its limits. If your tree becomes infected with harmful pathogens, it may succumb to its illness.

While you can watch for some diseases (such as blights or leaf spots), others, such as root rot, are harder to detect. If you want to protect your trees, you need to educate yourself. If you know some of the most common diseases, you can protect yourself and the trees.

You might also consider consulting with a professional (such as a certified arborist) if you have concerns. Keep reading to learn more about some of the most common tree diseases.


Anthracnose is a common tree disease caused by a fungus. It is most commonly seen in maple, oak, ash, sycamore, and dogwood trees, as well as in various other tree species. It usually results in leaves that turn brown and drop off prematurely, sometimes late in the fall or very early in the spring.

The leaves may also be spotted or have large patches of dead tissue. The infection can spread throughout the tree if drastic measures are not taken. The best way to combat the disease is through preventative measures such as proper pruning and watering techniques. Try visiting and avoid damage or injury by trimming and pruning.

Apple Scab

It is caused by a fungal pathogen known as Venturia inaequalis. This fungus is spread primarily by wind dispersal and overwinters in fallen leaves and other debris on the ground.

Symptoms of this disease include the appearance of dark purple-brown spots on the leaves and fruit, which eventually become covered in scabby lesions. This disease can be controlled by cultural practices such as removing fallen leaves, tree thinning to maximize air circulation, and using a fungicide such as copper oxychloride.

Cedar Rusts

Cedar rusts, a type of fungal disease, are common in many trees, especially cedars. They are especially common in young trees, as the rust can stunt their growth and reduce their vigor.

It can cause damage to the needles or foliage but will usually not kill the tree. Signs of rust can include yellow, orange, or yellow-orange spots on the tops or undersides of leaves.

To prevent cedar rust, it is important to regularly prune off infected leaves and branches and use preventative fungicides when planting young trees. Proper thinning and pruning of overcrowded branches will also help to reduce the spread of apple tree diseases.

Lethal Yellow of Palm

The lethal yellow of palm is one of the most common oak tree diseases that affect palm trees. It is caused by a species of fungus and is found in hot, wet climates. This disease can cause yellowing and wilting of the leaves, premature fruiting, and reduced frond production.

It can also cause the death of infected trees in severe cases. Proper care and preventive measures are necessary to avoid the lethal yellow of the palm, such as irrigation and fertilization management, removing infected plants, and applying fungicides as a preventative measures.

Identifying Different Common Tree Diseases

This guide has hopefully provided you with the basics of diagnosing various tree diseases. Now that you better understand the various tree diseases, you can go out into your yard and start diagnosing and treating your own trees.

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