How to Recognize the Signs of a Diseased or Dying Tree

Introduction

Trees are resilient and can live for decades, but they are not invincible. Just like humans, trees can become sick, weak, or diseased, and without early intervention, their health can quickly decline. Recognizing the signs of a diseased or dying tree is essential to preserving the overall health of your landscape and protecting your property.

In this post, we’ll cover the common signs of tree disease and damage, how to spot them, and what steps to take to remedy the situation. Early detection and action can save your trees—or at least prevent them from becoming a safety hazard.

1. Yellowing or Discolored Leaves

One of the most common indicators of tree stress is the color of the leaves. Healthy trees have vibrant green foliage (though it may change color in the fall). If you notice yellowing leaves, it could be a sign of several issues, including nutrient deficiencies, environmental stress, or disease.

Possible causes:

• Nutrient Deficiency: Trees need the right balance of nutrients like nitrogen, phosphorus, and potassium. A deficiency in one of these nutrients can cause leaves to turn yellow or even brown.

• Disease: Fungal infections such as oak wilt or anthracnose can also cause leaves to discolor, particularly early in the growing season.

Tip: If only the lower leaves are turning yellow, it could be a nutrient problem, while yellowing across the entire canopy could indicate a disease or pest infestation.

2. Premature Leaf Drop

Trees naturally shed leaves in the fall, but if a tree drops its leaves well before the cooler months, it may be a sign that something is wrong. Premature leaf drop can be caused by environmental stress, pest infestations, or a tree in decline due to disease.

Possible causes:

• Drought Stress: If your tree is not receiving enough water during the growing season, it might shed leaves early in an attempt to conserve moisture.

• Pests and Insects: Infestations like aphids or caterpillars can damage the tree’s foliage, causing it to drop prematurely.

• Root Problems: Root rot or damage from construction or digging can impact the tree’s ability to absorb nutrients and water, leading to early leaf drop.

3. Dead or Brown Branches

A tree with dead or brown branches might be in distress, especially if the issue is widespread throughout the tree. Brown or dead branches often signal poor health, though the cause can range from disease to environmental damage.

Possible causes:

• Fungal Infections: Trees infected with root rot or fungal diseases may exhibit dead branches that do not respond to pruning.

• Pests: Pests like borers, which tunnel into the trunk or branches of trees, can kill branches by disrupting the tree’s ability to transport nutrients.

• Environmental Stress: Extreme temperatures, drought, or physical damage can all lead to dead branches.

Tip: If you notice brown or dead branches on one side of the tree, it might be a sign of root damage or poor structural health, especially if the rest of the tree looks healthy.

4. Fungus or Mushrooms Growing Around the Base

Finding fungus or mushrooms around the base of a tree is one of the clearest signs that a tree is sick or dying. Fungus often indicates rot or decay in the root system, which can lead to the structural failure of the tree. Certain types of fungi, like Armillaria or Honey Fungus, can be particularly destructive, slowly decomposing the roots and weakening the tree’s foundation.

What to look for:

• Mushrooms or fungi growing on the ground or base of the tree.

• Mushrooms on the trunk: If you spot mushrooms on the tree itself, it’s likely the tree is infected with some type of rot.

Tip: If you see mushrooms or unusual fungal growth, it’s essential to contact an arborist immediately. Fungal infections are usually difficult to treat and can result in tree death if left unchecked.

5. Bark Peeling or Cracking

Healthy bark acts as a protective barrier for the tree, shielding it from pests, diseases, and environmental stress. If the bark is peeling, cracking, or falling off, it could be an indication of a serious issue.

Possible causes:

• Insect Infestation: Insects like borers often burrow under the bark, causing it to crack and peel. This exposes the tree to further damage and infection.

• Physical Damage: Damage from storms, lawnmowers, or construction work can harm the tree’s bark and lead to infection.

• Disease: Certain diseases like Canker Diseases can cause the bark to peel and crack, leading to the tree’s decline.

Tip: If the damage is widespread or if the bark is cracking in multiple locations, it's time to call a professional arborist for a full assessment.

6. Leaning or Tilting Trunk

If your tree begins to lean significantly or if it appears off-center, this could be a sign of root damage or instability. While some trees naturally have a slight lean, an increasing tilt could indicate that the roots are not securing the tree properly, which is often the result of disease or poor soil conditions.

Possible causes:

• Root Rot: The roots may be decaying or have been damaged, reducing the tree’s ability to stand upright.

• Soil Erosion: Soil erosion or construction near the tree can expose the roots, weakening the tree’s structure.

• Storm Damage: Severe weather can cause a tree to tilt, sometimes leading to permanent leaning if not addressed quickly.

7. Sap Dripping from the Tree

A tree that is leaking sap from its branches or trunk may be in distress. While sap can sometimes be a normal response to injury, excessive sap production is usually a sign of an underlying problem.

Possible causes:

• Pest Infestation: Insects like borers can cause the tree to leak sap in response to stress or injury.

• Canker Diseases: Canker-causing bacteria and fungi can cause trees to excrete sap as a reaction to infection.

• Physical Injury: Any type of physical damage to the tree’s trunk or branches can lead to sap leakage.

Tip: If you notice sap oozing from your tree, look for signs of insects or wounds in the tree that could be causing the problem.

8. Roots Exposed or Upturned

Roots that are visible above the ground or have been lifted from the soil are a sign that the tree is struggling. This can happen for several reasons, such as environmental stress, soil erosion, or diseases that weaken the root system.

Possible causes:

• Soil Erosion: Heavy rains or poor drainage can wash away soil around the base of the tree, exposing the roots.

• Root Rot: A diseased or rotting root system can cause the tree to tilt or shift, lifting roots out of the soil.

Tip: If the roots are exposed, avoid adding more soil around them without consulting an arborist. Covering the roots improperly can suffocate them and cause further harm.

Conclusion

Recognizing the signs of a diseased or dying tree early can save you from larger, more costly problems in the future. By staying vigilant and scheduling regular tree inspections, you can catch issues like disease, pests, or environmental stress before they escalate. If you notice any of the warning signs mentioned above, it’s best to contact a professional tree service immediately for a thorough evaluation and potential treatment.

Call to Action:

Don’t wait until it’s too late—contact our team of certified arborists today for a free tree inspection. We can help you identify any issues early and recommend the best course of action to keep your trees healthy and safe!