Is Your Tree Sick? A Guide to Identifying Tree Diseases

Your trees are a valuable asset, providing shade, beauty, and even increasing your property value. But just like any living thing, trees are susceptible to diseases. Identifying problems early is crucial for effective treatment and preventing the spread of disease to other trees in your landscape. As your trusted tree care experts at HLA Tree Service, we’ve created this guide to help you recognize the signs of a diseased tree. We proudly serve Hessmer, Louisiana, and the entire CenLA (Central Louisiana) region. (Avoyelles Parish, Rapides Parish, Grant Parish, St Landry Parish, Evangeline Parish, and surrounding parishes)

Why Early Tree Disease Detection Matters

• Saves Your Tree: Early intervention can often stop a disease in its tracks, preserving the health and longevity of your tree.
• Protects Other Trees: Many tree diseases are contagious. Spotting and treating a problem early can prevent it from spreading to your healthy trees.
• Prevents Costly Damage: Addressing a large-scale infestation or advanced disease is far more expensive than catching it early.
• Maintains Property Value: Healthy, thriving trees enhance the aesthetic appeal and value of your property. Invest in tree care to enhance your landscape’s health

Key Signs of a Diseased Tree to Watch For

Here are some common signs that your tree might be suffering from a disease:

• Leaf Problems:
  • Discoloration: Look for unusual spots, blotches, or yellowing of leaves (chlorosis). This could indicate fungal or bacterial infections, nutrient deficiencies, or even insect infestations. Examples: Leaf spot, Anthracnose, discolored tree leaves
  • Premature Leaf Drop: If your tree is shedding leaves outside of the normal fall season, it’s a cause for concern.
  • Wilting Leaves: Even if leaves are still attached, wilting can be a sign of vascular system issues (like fungal wilts).
  • Unusual Growths on Leaves: Bumps, galls, or powdery substances on leaves require examination.
• Branch Dieback:
  • Dead or Dying Branches: Dead branches, especially at the top of the tree (called “dieback”), can indicate a serious problem.
  • Cankers: Look for sunken or swollen areas on branches. These are often signs of fungal infections.
  • Unusual Branch Swelling or Deformity: This could indicate gall formation or other disease-related issues.
• Trunk Issues:
  • Cracks or Splits in the Bark: These can allow entry for insects and diseases.
  • Oozing or Weeping: Sap flowing from the trunk, especially if discolored or foul-smelling, is often a sign of infection.
  • Fungal Growth: Mushrooms or other fungal growths appearing at the base of the tree or on the trunk are definite warning signs.
  • Soft or Decaying Wood: If the trunk feels soft or spongy, it’s likely suffering from internal rot.
• Root Problems: (Often harder to detect but crucial)
  • Mushrooms at the Base of the Tree: As mentioned above, these often indicate root rot.
  • Declining Growth: Overall poor growth, even if other symptoms are less obvious, can be a sign of root problems.
  • Soil Disturbance: Uprooting of small areas of soil, possibly accompanied by a strange smell, can indicate root disease or decay.
• Overall Tree Appearance:
  • Stunted Growth: If your tree isn’t growing as it should be, it could be a sign of underlying disease or stress.
  • Sparse Canopy: A thin or patchy canopy can indicate a problem with nutrient uptake or vascular function.

Common Tree Diseases in Central Louisiana (CenLA)

Accurate identification is important for effective treatment. This guide provides common symptoms, but professional diagnosis is recommended for confirmation.

Oak Wilt

• Affected Trees: Primarily affects oaks, especially red oaks as they decline rapidly. White oaks and live oaks may be affected, but are more resistant.
• Key Visual Symptoms:
  • Leaf Discoloration & Wilt:
    • Red Oaks: Characterized by rapid wilting and browning of leaves, often starting at the top of the tree. Leaves may exhibit a “scorched” appearance, with brown edges moving inward. A unique symptom is “veinal necrosis,” where the veins of the leaves turn brown before the entire leaf dies. Color changes often start at tips and edges.
    • White Oaks: Symptoms are slower to develop. Leaves may exhibit browning and dieback of branch tips. Overall decline is less rapid than in red oaks.
    • Live Oaks: Yellowing or chlorosis of leaves, followed by browning. Defoliation can occur, but the tree may survive longer than red oaks.
  • Vascular Streaking (in Red Oaks): Peel back the bark of wilted branches to look for dark brown or black streaking in the sapwood (the layer just beneath the bark). This is a diagnostic sign of Oak Wilt in the red oak family. It’s best viewed on branches 1-4 inches in diameter. The streaking is caused by the fungus blocking the water-conducting vessels.
  • Fungal Mats (Rare): Under the bark, particularly on dead or dying red oaks, you might find fungal mats (pressure pads). These are often tan, gray, or black and have a musty or fruity odor. They are found between the bark and the wood, and are difficult to spot if you don’t know what you’re looking for. You usually need to peel back the bark to find them.
  • Overall Tree Decline: Rapid decline in red oak species. Gradual decline in white and live oak species.
• Look-alikes: Drought stress, root rot, herbicide damage, other vascular diseases.
• Considerations: Time of year (symptoms are often most pronounced in spring and early summer). Proximity to other infected oaks.

Anthracnose

• Affected Trees: Common on sycamore, ash, maple, oak (especially white oak), and dogwood.
• Key Visual Symptoms:
  • Leaf Spots and Blotches: Irregularly shaped brown or tan spots on leaves. The spots may have a darker margin. The tissue within the spots can eventually fall out, creating a “shot-hole” appearance.
  • Twig and Branch Dieback: Dieback can occur on young twigs and branches, especially in severe cases.
  • Cankers: Sunken, discolored areas on branches (less common, but possible).
  • Leaf Curl or Distortion: In some cases, leaves may curl or become distorted.
  • Early Leaf Drop: Trees with severe anthracnose may prematurely lose leaves.
• Look-alikes: Leaf scorch (environmental stress), other fungal leaf spots, insect damage.
• Considerations: Anthracnose is often more severe in cool, wet springs. Repeated defoliation can weaken trees over time.

Root Rot (General – specific symptoms vary by fungi)

• Affected Trees: Virtually any tree can be affected, but susceptibility varies. Common culprits are Armillaria, Phytophthora, and Fusarium.
• Key Visual Symptoms:
  • Above-Ground Symptoms (often non-specific):
    • General Decline: Slow growth, sparse foliage, dieback of branches from the top down.
    • Yellowing Leaves (Chlorosis): Lack of vigor.
    • Premature Leaf Drop:
    • Stunted Growth:
    • Smaller than Normal Leaves:
  • At the Base of the Tree & Roots (Critical for Diagnosis):
    • Mushroom-like structures (Mushrooms/Toadstools): Fruiting bodies may appear at the base of the tree, at the soil line, or near infected roots. Note their color, shape, and location. Armillaria is notorious for its honey-colored mushrooms.
    • Decayed Roots: Dig around the base of the tree and examine the roots. Look for soft, spongy, or discolored roots. A healthy root should be firm and have a light-colored interior.
    • Discoloration Under the Bark: Remove bark at the base of the tree (near the soil line) and examine the wood underneath. Look for staining or discoloration caused by the fungus.
    • Mycelial Fans: In some cases, you may see white or yellowish mycelial fans (fungal growth) between the bark and the wood. This is common with Armillaria root rot.
    • Sour or Musty Smell: May detect an unusual odor emanating from the decayed wood.
• Look-alikes: Drought stress, nutrient deficiencies, soil compaction, girdling roots, insect infestations, other diseases.
• Considerations: Poorly drained soils, previous tree damage, and stressed trees are more susceptible to root rot.
• Important Note: Diagnosing root rot often requires laboratory analysis of root samples to identify the specific fungus involved AND look at the historical site conditions.

Crape Myrtle Bark Scale (CMBS)

• Affected Trees: Only affects crape myrtles.
• Key Visual Symptoms:
  • White or Grayish-White Scale: Small, white or grayish-white, felt-like encrustations on the bark of the trunk and branches. They often cluster in branch crotches and around pruning cuts. They often initially appear as fuzzy white spots.
  • Black Sooty Mold: A black, powdery covering on the bark and leaves. This is caused by a fungus that grows on the honeydew excreted by the scale insects.
  • Honeydew: A sticky, sugary substance secreted by the scale insects. This can attract ants and other insects.
  • Reduced Flowering: Severe infestations can reduce flowering.
• Look-alikes: Lichen, mealybugs (mealybugs are more segmented), bird droppings (can be wiped off easily).
• Considerations: CMBS is relatively new to the US and is becoming increasingly common.

General Tips for Disease and Pest Identification:

• Observe the entire tree: Look for patterns in the symptoms.
• Examine multiple leaves and branches: This will help you determine if the symptoms are widespread or localized.
• Consider the tree’s history: Has it been stressed by drought, construction, or other factors?
• Take good-quality photos: Photos can be helpful for diagnosis and for consulting with an arborist.
• When in doubt, consult a certified arborist or your local agricultural extension office: They can provide expert diagnosis and treatment recommendations.

This guide is for informational purposes only and should not be considered a substitute for professional advice. Accurate diagnosis and treatment recommendations require a thorough on-site inspection by a qualified professional.

What to Do If You Suspect Your Tree is Diseased

1. Don’t Panic! Many tree problems are treatable, especially if caught early.
2. Take Pictures: Document the symptoms you’re seeing. Photos will be helpful for diagnosis.
3. Contact HLA Tree Service: Our certified arborists can accurately diagnose the problem and recommend the best course of treatment.
4. Avoid DIY Treatments: Using the wrong treatment can be harmful to your tree and the surrounding environment. Trust the professionals.

HLA Tree Service Company, Your Local Tree Care Experts in Hessmer and CenLA

At HLA Tree Service, we are committed to the health and well-being of your trees. We offer a full range of tree care services, including:

• Tree Disease Diagnosis & Treatment
• Certified Tree Assessments
• Tree Pruning & Trimming
• Tree Removal
• Emergency Tree Services
• And More!

Call us today at 318-563-0011 for a free consultation! We’re here to help you keep your trees healthy and beautiful.

Protecting your trees is an investment in your property, community and the environment. By understanding the signs of tree diseases and acting quickly, you can help ensure the health and beauty of your landscape for generations to come. When service and quality matter, we’re here to help every step of the way. Contact HLA Tree Service Today!