How To Save A Dying Oak Tree?

How To Save A Dying Oak Tree?

The most common reason for oak trees to die is disease. Oak wilt and oak leaf blisters are the two most widely observed fungal infections in oak trees.

There are various signs and symptoms to look out for if you suspect that an oak tree is dying. These are seen on the tree’s leaves, branches and trunk. If there are lesions or cracks that look out of the ordinary, you will need to narrow down the possible causes in order to properly treat and save your tree.

In this article, we will discuss the signs to look out for if you suspect that your oak tree is dying, and what you need to do in this situation.

Why is my oak tree dying?

Oak wilt

This is one of the most serious tree diseases to damage oak trees. The fungus can infect any type of oak tree, but it infects water oaks and red oaks the most, and it affects the plant’s ability to retain water. Live oaks are less likely to get oak wilt, but if they do get infected, they suffer more damage because of the interconnectedness of their root systems.

Infected trees will have yellow veins in their leaves that become brown over time. The leaves will also fall off prematurely. The young leaves on infected red oaks’ will wilt faster than normal and fall off sooner, too. Older leaves will turn pale green or even a shiny brown in some cases.

Fungal mats can also form underneath the bark of the tree. The spores in the fungal mats give off an odor that smells pleasant to insects, and these insects will help the mats expand further across the trees.

It is quite easy for oak wilt to spread to other trees, so it needs to be treated as soon as possible. It is best to hire a professional to confirm the diagnosis and to save the tree with the appropriate treatment.

Oak leaf blisters

Oak leaf blisters have been observed in various species of oak, and are caused by the Taphrina caerulescens fungus. Although they have been observed in different types of oak, the red oak seems to be the most susceptible to the fungus. This disease causes raised, circular blisters on the upper surfaces of the leaves. The lesions can either be yellow or green, but they will all turn brown over time. The more lesions there are on the leaf, the more the leaf will curl.

This disease may not threaten the overall health of a mature oak tree, but it does affect the aesthetic of the tree and causes its leaves to fall off prematurely.

You can get rid of the fungus by spraying the tree with fungicide in the early spring before the tree’s buds begin to swell. The fungicide may not be as effective if applied after the buds have broken.

How can I tell when an oak tree is dying?


An oak tree that is healthy will stand as straight and tall as it can. An unhealthy tree will start to lean to one side, usually due to the roots becoming shallow and weak. The leaning could be due to strong rain and winds, but it could also be attributed to improper pruning techniques.

Dead bark

Dead bark, or cankers, form when bacteria and fungi make their way into the tree’s tissue via a cut branch or an open wound on the bark. The pathogens infect the tree and cause it stress, leading to the formation of cankers. You can ask a professional to remove the cankers and they will gladly seal them off so that they do not worsen.

Try not to do your pruning during the spring and fall, because this is when the bacteria that cause the canker are most active.


If you notice parts of the oak tree starting to decay, you need to address it immediately; otherwise it can easily destroy the tree from the inside out.

It can be tricky to spot decay in its early stages because it often starts in the middle of the tree and will only display noticeable signs like stunted growth, mushroom-like growths and dead branches when the decay is serious.

Branches that break easily

If the tree’s branches become dry and easy to break, it might mean that your once-healthy tree has deadwood. This happens when a fungal infection has become so bad that the tree has essentially been hollowed out from the inside. This can also happen when trees suffer through drought or a strong storm that causes the bark to decay.

How do I save a dying oak tree?

Prune off sick branches

If there are any dead or dying branches, cut them off to help save the tree. You can take care of issues such as weak joints, deadwood and poor structure when you do this. If the disease is only on a specific branch, it makes sense that the best way to get rid of it is simply to cut it off.

Make sure you use appropriate pruning methods and sterilize the equipment after pruning.

Do not use too much mulch

You could actively suffocate the roots of the oak tree if you apply too mulch on the base of the tree. If the roots are unable to breathe, the tree trunk and roots will rot and become susceptible to opportunistic pathogens and pests.

Clear away excess mulch from the base of the tree, leaving just enough.

Correct your watering techniques

Try not to overwater your tree as this can be fatal, especially in younger trees. If the roots of the tree are left to stand in constantly waterlogged soil, they can decay and develop root rot.

Make sure the soil is well-draining and gets a lot of direct sunlight to help it dry out faster, so that the tree does not have to deal with soggy soil all the time.

Spray fungicide

If your tree has fungal disease in its leaves, branches and trunk, pruning alone may not be enough to control the spread. Spray the tree with fungicidal spray to help clear the disease.


The most probable reason your oak tree is dying is a disease, such as oak wilt or oak leaf blisters. Overwatering and placing too much mulch around the base of the tree can also cause the roots to rot and decay, making the tree more vulnerable to secondary infections.

If you want to save your oak tree, you have to correctly identify the cause of the problem so that you can treat it accordingly and save the tree.

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