The Most Common Tree Diseases

The Most Common Tree Diseases

Trees are very susceptible to tree diseases. Tree diseases include a wide range of fungi, insect larvae, and fungi that can affect your trees and threaten their health. The fungi that can infect your trees include pathogens, fungus gnats, leafhoppers, scale insects, and plant viruses. In the past, it was believed that the diseases were caused by rodents but this has not been proven yet.

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The primary symptom of a tree disease is the white spots that appear on the infected part of the tree. They are called needle shaped. There can also be discoloration or blackening of the infected area of the tree bark. Sometimes, the infected leaves will begin to turn yellow. Sometimes, the affected bark of the tree may crumble and fall off. The tree disease symptoms are sometimes confused with other diseases such as fungal infections.


You need to identify a tree disease before you try to treat the tree. The worst thing you can do is wait for the disease to spread to your trees. If you suspect that your trees are suffering from a tree disease, you should immediately take measures to eliminate the problem. Some of the tree diseases affecting trees in California are:


Fungi: The most common tree disease in California is the fungal disease known as Fungi. It can affect a wide variety of trees including, but not limited to, trees like spruce, pine, hemlock, cypress, and Douglas fir. The fungus gnats can gnaw away at your trees leaves and cause them to become dry and fall off.


Many types of fungi attack your trees and cause them to die. Some of these tree diseases include Black Spotted Rot, Botrytis wendtii, Brown Canker, Dothistroma, Drywood Rust, Mildew, Mite, Pink Mold, Powdery Mildew, Stem Root Disease, and Virus. These fungi can attack various parts of your trees including the bark, twigs, leaves, and branches. To control these types of tree diseases, you must first remove the fungi and disinfect the affected areas with insecticide.


The fungus gnats are usually found in moist shady areas. They eat the sap of trees, especially the leaves. When the tree has an excess of sap, the fungus gnats take advantage of it and gnaw away at the tree. There are different types of fungus gnats such as Drywood Fly, Stachys, and Phyllanthus. There are treatments available to control the disease. To prevent the tree from suffering from drywood flies, you should regularly check for dampness around the leaves.


Phyllanthus: The other common tree disease in California is Phyllanthus. The name of the fungus gnats comes from the plant called phyllanthus which is commonly found on California green trees. It thrives in poorly oxygenated areas such as low branches and soil that have low pH. The affected area will turn yellow and fall. To control this type of tree disease, you must first remove the rotting dead leaves on a regular basis.


A very important thing to know about tree diseases is that they can spread very fast. For example, the disease that affects trees in May can affect trees in May or June. Do not leave any food on the trees. Clean the tree regularly and remove any fallen food or petals. If you observe these tips, you will not have to worry much about diseases on your tree.


Powdery Mildew: This is a common tree disease that affects mostly trees growing in wet climates. The affected part of the tree may turn yellow with mild to severe cracking. The leaves will fall off and new leaves will not grow. To control this type of tree disease, you need to regularly mist the affected parts of the tree using water. You may also use fungicides to control fungus gnats.


Damp Heartwood: This is another common tree disease that mainly affects conifers. The affected part of the tree will develop brown spots and you will notice a thickening of the bark. However, there is no noticeable change in the appearance of the tree leaves. The affected part of the tree will eventually fall off. To prevent the disease, you can reduce the number of watering your trees.


Rust: This is a disease that infects many types of conifers and deciduous trees. The affected part of the tree will have distorted leaves and the bark will grow brown spots. Rust will spread, if the affected area is not given enough ventilation. To solve this problem, you can use a fungicide to control fungus gnats.