Tree Diseases In Houston

26 Jun, 2015
arborist in Houston

No area of the country is immune to tree diseases. This means that the trees on your Houston property are prone to various infestations and illnesses. Trees can be damaged by the environment, construction, pests, and disease. In many cases, people use the term disease to refer to both diseases and insect infestations as they can sometimes cause similar damage. The exact illnesses that affect trees will vary from location to location, but the following are some of the most common found in Houston and the surrounding areas of Texas.


Chlorosis is a disease affecting Houston plants due to an iron deficiency. When the plant does not have access to enough iron, chlorophyll formation is hampered, making the leaves turn yellow. This can happen because the tree doesn’t have enough nutrients to access the iron or a lack of nitrogen or iron within the soil. You can treat this tree disease with a fertilizer containing high nitrogen levels.

Citrus Greening

Citrus greening affects citrus trees in particular and is considered the most destructive of all diseases that do so. It occurs due to a bacteria transmitted by psyllids, a type of insect. An arborist can diagnose your citrus trees with the issue and you can prevent them from contracting the tree disease in Houston by preventing psyllids with natural remedies or insecticides.


Gall occurs due to bacterial or insect damage to a tree. With this condition, the trees growth is affected by parasitic organisms which cause abnormal growths throughout the plants. The growths can be in the form of hard balls, fuzzy areas, or masses on twigs. Galls do not harm the trees as they are simply a part that looks unlike the rest. Because they are just another part of the plant, you cannot easily see results in treatment, even by targeting the specific bacteria, fungi, or insects.


Most people will recognize mildew and this black substance can accumulate on the twigs and leaves. Along with mildew, you may notice whiteflies which secrete a substance containing sugar that encourage mildew to grow. Although mildew won’t damage your trees, it can be unattractive. You can take care of mildew by improving airflow by thinning out the trees limbs or using soapy water and/or horticultural oil repeatedly.

Oak Wilt

Oak wilt is due to a particular fungus that clogs vessels of a tree that are responsible for transporting water. This leads to the tree wilting and dying within several weeks to months. Fungus can be spread by an insect or via root grafts. When multiple oak trees are in close proximity, this is more likely to occur. Houston residents should focus on preventing oak wilt by avoiding using unseasoned firewood. Wood that comes from trees with oak wilt is an issue. It is okay to use well-seasoned firewood as it will no longer pose a risk. You should also minimize the amount of pruning of your red and live oaks between February and June. This is when the fungal spores and beetles are most active, causing a potential increase in transmission of the disease.

You can also try to prevent this from affecting your trees by planting a variety of species.


Scale is a type of insect that will infect tree limbs and twigs, sucking their sap. Because the insects gather underneath leathery coverings, it is hard for someone other than a trained arborist to identify this issue. It is also possible to find ants around a scale infection on your Houston tree since they will live off the secretions, unknowingly protecting scale. Scale is also sometimes associated with a fungus known as sooty mould. An arborist will suggest treating scale with soapy water or horticultural oil combined with thinning out the twigs and leaves to improve air flow.

Southern Pine Beetles

Southern pine beetles typically affect pine trees in a periodic fashion and can be fatal. Some signs of these beetles include whitish-yellow resin tunnels on the tree and reddish sawdust along the ground or crevices. After beetles infest a tree, they will complete their entire life cycle in the same plant, causing the needles to go from green to yellow to red-brown and the tree to die. In Houston forests, you can control southern pine beetles by controlled burns or thinning pine stands. At your home, however, you will need to rely on other methods such as pesticides.

Spider Mites

Spider mites are a type of tiny insect that feeds on the leaves of a tree and in the process sucks nutrients from its cells. The leaves that they attack will become speckled before dropping off. If the spider mites are not stopped, the tree can eventually die, but you can naturally take care of the problem by encouraging beetles, ladybugs, or other natural predators to reduce the number of mites.

Identifying Tree Disease

It is sometimes possible for an untrained homeowner to diagnose tree diseases in Houston. However, in most cases you will want to have an arborist evaluate your plants. They can determine exactly which disease or infestation your trees are suffering from, which ones are affected, and recommend a course of action, whether that means treatment or removal.

Preventing Tree Diseases in Houston

There are also some steps you can do to prevent tree diseases in Houston, both on your property and in the community.  Trees that are visibly decayed or dead should be removed as soon as possible. You may also want to use a fungicide. It can help prevent fungus-related issues such as oak wilt as well as insecticide to prevent bugs. This can spread disease or cause damage through an infestation. Infected trees should be completely remove it from your yard. If that is not an option, you can isolate it by digging a trench. Ensure that is at least four feet deep and cuts off its root system. Certified arborists can also offer suggestions of ways to prevent your trees from contraction an infestation or disease.