Oak trees are one the most beloved trees in the world. Oak trees are most well-known for their height (often reaching 100 to 150 feet), and adaptability. However, they aren’t immune to all kinds of threats.

Oak leaf blister, armillaria roots rot anthracnose and oak wilt are the most common oak tree diseases. You can save your oak tree in general by feeding it and trimming the affected branches.

What are some common problems to watch out for when you have an oak tree? We are here to help you solve the problem. Continue reading!

What Kills Your Oak Trees?

Oak trees can be susceptible to many problems, even though they are some of the most disease-resistant trees.

For example, oak tree saplings are more susceptible to problems than full-grown oaks. Full grown oaks, however, can still have problems over their lifetime.

Below is a list of oak tree diseases and their causes, as well as how to treat them.

DISEASE OF THE COMMON OAK	TREATMENT	SEVERITY
Oak Leaf Blister	Watch and Monitor	Low
Armillaria Root Rot	Take out infected roots and trees	High
Anthracnose	Monitor and Prune Infected Branchs	Medium
Oak Wilt	Regulation or direct control of fungicides	Red Oak-High, White Oak – Low
Bacterial Leaf Scorch	Replant resistant Species and Remove Infected Trees	Medium
Powdery Mildew	Take out infected branches and dead leaves	Low
Hypoxylon Canker	Take down infected trees	Medium
Actinopelte Leaf Spot	Reduce Stress and Remove Infected Sections	Medium
Mistletoe	You can either cut the infected limbs or take off the tops	Low
Galls	Get rid of infected twigs	Low-High

You can find our guide to the 10 early signs of a dying oak tree in.

Oak Leaf Blister

Although most oak trees are affected by this fungus-based illness, red and black oaks are more susceptible. Despite the fact that some oaks may be more susceptible than others, the severity of this disease is still very low. The oak tree may not suffer any severe symptoms in cases of mild afflictions.

Oak leaf blister can cause spots. This is the most severe form of oak leaf blister. These patches appear to be light-colored blisters on the leaves. They then turn brown and look more like a kind of sap. These patches are caused by fungus overgrowth.

Oak leaf blister leaves grow faster than those that don’t have the tissue. This is because the spores take longer to germinate in the winter freeze. These spores are usually found before the leaves can bud and can cause havoc when growth resumes in spring.

In the fall months, spores can spread from infected fungus-infected individuals. This is a natural cycle that fungicides don’t usually have much control over. We recommend this Natria’s Neem Oil Spray, which is effective for both insects as well as fungi. This should be applied before the buds begin to break in the spring.

Armillaria Root Rot

Armillaria rootrot is a severe problem for oak trees. It can affect everything, from roots to whole trees.

Expect a gradual decline in the tree. In wet weather, mushrooms structures will form around the roots and base of the tree. These mushrooms have a honey-colored appearance that doesn’t make them look as dangerous as they actually are. But now you know. This is not a fungus that should be ignored.

Armillaria Root Rot is easily identifiable by the mushroom clusters, but there are other signs. This affliction can cause poor growth and yellowing of leaves and needles, as well as an increase in the production of seeds and pinecones.

Flat white fungal growth sheets may be paired with thin, black fungal strands near the trunk’s base. You may see the extra resin in the tree or the wood may be too soft and stringy.

There are many symptoms. We have only scratched the surface. This severe condition will not only kill your oak tree but will also make it difficult to manage.

How can you save your oak tree.

Armillaria root Rot can be stopped by reducing stress around your oak tree. Mulching the soil around the tree’s base to provide nutrients and water can save oak trees. This is especially important during droughts when stress levels are high.

Avoid inflicting injury on your trees. Trees that are infected by wounds are more likely to get armillaria rootrot. Your tree should be kept safe from lawnmowers and other sharp tools such as weed whackers or power tools.

Anthracnose

Although Anthracnose may not be the most serious oak tree disease on this list it should be considered. Your oak leaves might be turning a brownish-rusty color. Anthracnose is more common in the autumn to oak seasons.

You can avoid over-pruning affected branches and the fear that they will spread or you can closely monitor your trees.

When you’re just planting oak trees, make sure they are spaced far apart to allow for plenty of sunlight and fresh air.

Also, it’s important to plant your oak tree at the right time of the year . HTML3_

Chemical control is an option. However, there are other options to address the issue. You will need to do a combination of pruning, sanitation, monitoring, and other measures to help this oak tree problem.

Oak Wilt

This fungal disease is very common in the Southeastern United States. It may have different symptoms for red oaks than white oaks.

Oak wilt is transmitted via fungal spores or one of many bark beetles. This can cause severe damage to your trees.

Oak wilt can affect both red oak trees as well as white oak trees in different ways.

To understand the following sections about oak wilt and white oak rot in red oak trees and white Oak trees, please read our guide on the key distinctions between red and white oak tree.

Red Oak Wilt

Oak wilt is a more serious and rapidly growing problem in red oaks.

Oak wilt is a condition that affects red oak trees. It can be present for a few weeks before symptoms become apparent. The tree may die within a few months. Oak wilt in oak trees can be more severe than that experienced by white oak trees.

The first signs of wilting are the red oak leaves turning a bronze colour. This usually starts at the edges of your tree, along with small branches and the ends, and then moves to the trunk. As they discolor, the leaves will slowly fall.

Oak wilt fungus is still growing and produces a sticky layer under the bark of infected trees that can range from light grey to tan. This layer can cause the bark to become brittle and eventually the tree will die.

Oak wilt is the most common reason red oak trees die.

White Oak Wilt

Because they live for many years after initial infection, white oaks are resistant to oak wilt.

Oak wilt can be controlled in white oak trees in many ways. These include regulatory prevention and direct control with fungicides.

Bacterial Leaf Scorch

Bacterial Leaf Scorch is an oak tree disease that causes water to stop flowing, yellowing or reddening to the tree, and then leaves turn brown. The tree’s hardiness is affected and the leaves eventually fall. When water movement is low, symptoms often develop after a summer drought.

Usually, tree-hopping insects spread bacterial leaf scorch.

Because regression is a gradual process of decline, the severity is moderate. An oak tree can survive for 5-10 years more after bacterial leaf scorch is removed.

Bacterial leaves scorch is a less specific disease that affects red, white and bur oaks as well as maple trees and other varieties.

To treat bacterial leaf scorch you will need to remove the affected trees and replant the resistant species of trees in the same area.

You should look into insect control like Organic deet-free bug repellent. Although spray treatments are not available at this time, controlling the spread of bacterial leaf scorch by insects is a good first step.

Powdery Mildew

Powdery mildew will look more like baby powder was sprayed on your tree’s leaves.

Powdery mildew occurs when many fungi are combined to form a white powder on infected trees’ leaves. This disease is not considered fatal according to the Clemson Cooperative Extension. However, it can cause severe plant damage. Powder mildew has a moderate severity.

Powdery mildew is not limited to white spots on oak trees. Leaf curling, discoloration and other abnormal growths are also symptoms of powdery mildew.

Powdery fungal growth on oaks isn’t always obvious. Although it can be visible, it tends not to appear on the lower leaves. Extreme cases of abnormal oak tree growth can lead to yellow-brown colored, dried leaves that may become yellow-brown.

If you see white spots or discoloration in a few leaves, powdery mildew management is possible. The fungus can be controlled by simply removing the affected leaves.

As you remove any dead leaves, trim the dead branches. This will prevent powdery mildew spreading into the following season.

Hypoxylon Canker

Hypoxylon cankers, which are common in oak trees of all varieties, only start causing symptoms when they are stressed. Similar to canker sores in humans, bacteria and pathogens respond to stress and take effect.

Texas A&M’s Agrilife extension has shown us that the symptoms of hypoxylon canker are similar to those of other trees that are in decline.

Hypoxylon cankers can cause yellowing, browning, reduced growth rates, thinned branches and canopy, as well as white stringy sap around base. They aren’t nearly as severe as oak wilt or anthracnose in a red oak tree.

This oak tree threat is of more concern than the others we are discussing today.

Hypoxylon canker is a condition that affects oak trees. It must be controlled by eliminating stress or at least reducing it. Vertical mulching is a method that adds nutrients to the soil around trees, enriching their roots and strengthening them against stress-induced disease.

You may be able to save your tree by performing remedial pruning. This will allow you to remove stress-sensitive areas before hypoxylon cankers spread throughout the oak tree.

Tree removal is an option if all else fails. Once it spreads, white-rot can quickly kill trees and pose a danger to their vitality or safety.

Actinopelte Leaf Spot

Actinopelte, another affliction with moderate severity, is caused by fungusspores. They last through the winter and get agitated in spring by rain and wind. Leaf spots may appear, and can join together to form larger, more irregular blotches. Green leaves with a dark or reddish-brown hue will appear sickly. The most severely affected specimens may fall to the ground before they are fully healed.

Management of actinopelte is centered around the ideas of transplanting, minimizing stresses, and properly fertilizing- all these things go hand in hand to make an oak tree thrive.

Mistletoe

You’ve probably heard of mistletoe. I.E. I.E. Did you know that mistletoe can actually be a parasitic pest?

It wraps itself around oak trees to take water and minerals from them. However, the severity of the problem is very low because mistletoe can handle food sources such as chlorophyll on its own. Although mistletoe does not cause any harm to trees, it should still be closely monitored.

To solve this problem, you will need to trim the branches that are too tight with the vine. Also, it is possible to remove the tops from the mistletoe.

Galls

The insects can make oak trees look less attractive by creating these spots. They could cause enough damage to make the oak tree die. They can be very severe and it is hard to predict what will happen if they join the party.

Galls are abnormal growths or swellings, most commonly caused by small wasps. There is no way to completely cure galls on oak trees. Galls cannot be removed once they are established on oak trees.

Galls are more common than any other serious problem, but they can cause severe problems, such as the death or disfigurement of trees. The symptoms are often somewhere in between, such as severe leaf deformities and premature leaf drops.

Galls can be managed by simply removing fallen leaves that have been affected by gall-makers. To prevent this problem from spreading quickly, prune or remove any twigs with galls.

That’s All For Now!

We now know more about oak tree diseases and other threats. It’s obvious that these giants of durability have limitations.

It is important to choose the best oak trees to plant. Our guide to the best oak trees for planting can be found here.

To keep your oak trees strong and healthy, you can use fungicides. You might also find that spraying is more effective than removing infected branches and roots, depending on the type of oak disease you have and when it was discovered.

We hope you find this helpful and that it helps you to understand what to expect.