Common Tree Fungi Found in Texas

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Texas trees are exposed to a variety of fungal diseases that can affect their health, structure, and longevity. Some fungi primarily cause cosmetic damage, while others can lead to severe decline, decay, or tree failure if left unmanaged.

One of the most destructive tree diseases in Texas, Oak Wilt affects live oaks and red oaks by blocking water movement within the tree.

Symptoms:

• Leaf discoloration
• Veinal necrosis
• Rapid wilting
• Canopy thinning
• Branch dieback

A stress-related fungus that commonly attacks weakened oak trees during drought or environmental stress.

Symptoms:

• Peeling bark
• Gray or black fungal growth
• Dead branches
• Rapid canopy decline

A common leaf disease that develops during cool, wet weather.

Symptoms:

• Brown leaf spots
• Leaf curling
• Premature leaf drop
• Twig dieback

Also known as "Shoestring Root Rot," this fungus attacks roots and lower trunks.

Symptoms:

• Thinning canopy
• Yellowing leaves
• Mushrooms near the base
• Root decay
• Tree instability

A serious decay fungus that weakens roots and lower trunks.

Symptoms:

• Shelf-like conks on the trunk
• Internal wood decay
• Leaning trees
• Sudden tree failure

A group of fungi that cause internal trunk decay while the outside of the tree may appear healthy.

Symptoms:

• Hollow trunks
• Mushrooms or conks
• Structural weakness
• Increased risk of failure

A fungal disease that appears as a white powdery coating on leaves.

Symptoms:

• White fungal growth
• Distorted leaves
• Reduced vigor
• Premature leaf drop

A broad category of fungal diseases affecting root systems in wet or poorly drained soils.

Symptoms:

• Yellowing leaves
• Sparse canopy
• Mushrooms near roots
• Leaning trees
• Root decay

• Mushrooms growing near the tree base
• Shelf-like conks on the trunk
• Dead branches
• Excessive leaf loss
• Canopy thinning
• Cracks or cavities in the trunk
• Peeling bark
• Sudden decline

Many fungal diseases cannot be cured once they become established. Regular inspections, proper pruning, adequate watering, and prompt treatment of stressed trees can help prevent serious damage and extend the life of valuable trees.

At CBM Tree Service, tree health assessments can help identify fungal diseases early and determine the best management options to protect your trees and property. 

Oak Leaf Blister is a fungal disease caused by Taphrina caerulescens that affects many species of oak trees. The disease primarily impacts the leaves, causing raised, blister-like spots that can become discolored as they age. Although Oak Leaf Blister can make a tree look unhealthy, it is usually considered a cosmetic problem and rarely causes long-term damage to healthy, established oaks.

The disease is most common during cool, wet spring weather when newly emerging leaves are especially susceptible to infection.

Oak Leaf Blister is most often found on:

• Red Oak
• Shumard Oak
• Water Oak
• Willow Oak
• Black Oak
• Pin Oak
• Occasionally Live Oak and other oak species

Common symptoms include:

• Raised, blister-like bumps on leaves
• Light green, yellow, or pale spots that later turn brown
• Thickened or distorted leaf tissue
• Leaf puckering or curling
• Premature leaf drop during severe infections
• Scattered blisters across the leaf surface

Symptoms usually appear shortly after leaves emerge in the spring.

The fungus spreads through:

• Wind-blown spores
• Rain splash
• Moist spring weather
• Infected fallen leaves

Spores infect young leaves as buds begin to open.

The disease is favored by:

• Cool, wet spring weather
• Prolonged leaf wetness
• High humidity
• Frequent rainfall during bud break

Dry spring conditions typically result in fewer infections.

In most cases, Oak Leaf Blister is not life-threatening. Healthy trees usually recover without treatment.

However, repeated severe infections may:

• Reduce photosynthesis
• Cause premature leaf drop
• Stress young or newly planted trees
• Slightly reduce overall vigor

Most mature trees do not require treatment.

Management options include:

• Raking and disposing of infected leaves
• Maintaining proper watering during dry periods
• Mulching around the root zone
• Promoting overall tree health
• Preventive fungicide applications before bud break for valuable specimen trees, when recommended

Once symptoms appear on the leaves, fungicides are generally no longer effective for that growing season.

• Keep trees healthy with proper watering and mulching.
• Remove fallen infected leaves in autumn.
• Avoid unnecessary tree stress.
• Improve air circulation where practical.
• Monitor trees during cool, wet spring weather.

Oak Leaf Blister is usually more of an aesthetic concern than a serious health threat, but early identification can help distinguish it from more damaging oak diseases, such as Oak Wilt or anthracnose. Maintaining overall tree health allows most oaks to recover naturally and continue producing healthy foliage in future growing seasons. 

Anthracnose is a common fungal disease that affects many shade and ornamental trees, especially during cool, wet spring weather. The disease attacks developing leaves, twigs, buds, and young shoots, causing leaf damage, premature defoliation, and overall stress to the tree.

While Anthracnose can make trees appear unhealthy, it is rarely fatal to established, healthy trees. However, repeated infections can weaken trees over time and make them more susceptible to insects, drought stress, and other diseases.

• Live Oak
• Red Oak
• White Oak
• Sycamore
• Ash
• Elm
• Maple
• Pecan
• Walnut

Common symptoms of Anthracnose include:

• Brown, tan, or black blotches on leaves
• Irregular dead areas along leaf veins
• Leaf curling or distortion
• Premature leaf drop
• Sparse or thinning canopy
• Dead twigs and young shoots
• Delayed leaf emergence in spring

In severe cases, trees may lose a significant portion of their foliage early in the growing season.

Anthracnose fungi thrive in:

• Cool, wet spring conditions
• Extended periods of rain
• High humidity
• Poor air circulation within the canopy
• Dense, overcrowded tree growth

Spores spread through rain splash, wind, and infected plant material.

Yes. Management typically focuses on improving tree vigor and reducing favorable conditions for fungal growth.

Treatment options may include:

• Proper pruning to improve airflow
• Removal of infected leaves and twigs
• Tree health assessments
• Mulching around the root zone
• Proper watering during dry periods
• Preventative fungicide applications for high-value trees when necessary

• Prune trees regularly to improve air circulation
• Remove and dispose of infected leaves
• Avoid overhead irrigation when possible
• Maintain proper tree spacing
• Water deeply during drought periods
• Promote overall tree health through proper care

Although Anthracnose rarely kills mature trees, repeated defoliation year after year can weaken a tree and increase its susceptibility to other problems. If you notice recurring leaf loss, branch dieback, or declining tree health, a professional tree health assessment can help determine the best course of action.

Healthy trees are much better able to withstand Anthracnose infections. Regular pruning, proper watering, mulching, and routine inspections can help reduce disease severity and promote long-term tree health.

At CBM Tree Service, tree health assessments can help identify Anthracnose symptoms early and provide recommendations to protect valuable shade trees and maintain a healthy, attractive landscape. 

Ganoderma Root Rot is a serious fungal disease that attacks the roots and lower trunk of trees. It is caused by fungi in the Ganoderma genus, which slowly decay the wood inside the tree, weakening its structural integrity and increasing the risk of failure.

This disease is common throughout Texas and can affect many hardwood tree species. Unfortunately, once a tree is infected, there is no known cure, making early detection and monitoring essential.

• Live Oak
• Red Oak
• Cedar Elm
• Pecan
• Ash
• Maple
• Hackberry
• Mesquite
• Other hardwood species

Common symptoms of Ganoderma Root Rot include:

• Thinning canopy
• Yellowing or undersized leaves
• Branch dieback
• Slow decline over several years
• Reduced vigor and growth
• Dead limbs in the upper canopy
• Leaning trees
• Structural instability

The most recognizable sign is the appearance of a conk (a shelf-like mushroom) growing from the lower trunk, root flare, or base of the tree.

Ganoderma conks are often:

• Shelf-shaped or bracket-shaped
• Reddish-brown, dark brown, or varnished-looking
• Hard and woody in texture
• Located near the base of the trunk
• Annual or perennial depending on the species

The presence of a conk usually indicates significant internal decay has already occurred.

Ganoderma fungi decay the structural wood inside the trunk and root system. A tree may appear relatively healthy on the outside while experiencing extensive internal decay.

This can lead to:

• Root failure
• Trunk failure
• Sudden tree collapse
• Increased storm damage risk
• Hazards to homes, vehicles, and people

The fungus spreads through microscopic spores released from mature conks. Spores enter through wounds, stressed roots, or naturally weakened areas of the tree.

Factors that may contribute to infection include:

• Drought stress
• Soil compaction
• Root damage
• Construction activity
• Poor growing conditions

Unfortunately, there is no effective cure for Ganoderma Root Rot once a tree becomes infected.

Management options may include:

• Tree health assessments
• Monitoring tree stability
• Reducing stress through proper watering and mulching
• Pruning hazardous limbs
• Risk evaluation of affected trees
• Tree removal when structural failure becomes likely

Removal may be recommended when:

• A conk is present and significant decay is suspected
• The tree shows severe canopy decline
• Large dead limbs are developing
• The tree is leaning or unstable
• The tree poses a risk to people or property

• Avoid damaging roots during construction
• Prevent soil compaction around trees
• Water during extended drought periods
• Maintain proper mulch rings
• Schedule routine tree inspections
• Address tree stress early

Because Ganoderma Root Rot causes internal decay that cannot be seen from the outside, many trees fail without obvious warning signs. Regular inspections can help identify fungal conks, structural concerns, and potential hazards before failure occurs.

At CBM Tree Service, tree health assessments can help identify Ganoderma Root Rot and other decay-related issues, allowing property owners to make informed decisions about tree preservation, risk management, and property safety. 

Powdery Mildew is a common fungal disease that affects the leaves, shoots, and sometimes flowers of many trees, shrubs, and ornamental plants throughout Texas. It appears as a white or gray powdery coating on plant surfaces and is most common during periods of high humidity, warm days, and cool nights.

Although Powdery Mildew rarely kills mature trees, severe or repeated infections can weaken plants, reduce growth, diminish appearance, and increase susceptibility to other stresses.

• Live Oak
• Red Oak
• Crape Myrtle
• Sycamore
• Maple
• Pecan
• Dogwood
• Rose Bushes
• Various ornamental shrubs

Common symptoms include:

• White or gray powdery coating on leaves
• Distorted or curled leaves
• Yellowing foliage
• Stunted new growth
• Premature leaf drop
• Reduced vigor
• Infected buds and shoots

The fungus is often first noticed on young leaves and tender new growth.

Powdery Mildew fungi thrive under conditions such as:

• High humidity
• Poor air circulation
• Dense canopies
• Overcrowded plantings
• Shaded environments
• Warm temperatures

Unlike many fungal diseases, Powdery Mildew does not require standing water on leaves to develop.

While often considered more cosmetic than deadly, severe infections can:

• Reduce photosynthesis
• Slow plant growth
• Cause premature defoliation
• Stress already weakened trees
• Affect the appearance of landscapes

Yes. Management often includes:

• Proper pruning to improve airflow
• Removal of heavily infected foliage
• Increasing sunlight penetration
• Maintaining tree health through proper watering
• Fungicide applications when necessary
• Reducing overcrowding between plants

• Prune trees regularly to improve air circulation
• Avoid overcrowding plants
• Water properly during dry periods
• Remove infected leaves when practical
• Promote healthy tree growth
• Schedule routine tree inspections

If Powdery Mildew returns year after year, causes significant leaf loss, or affects valuable landscape trees, a professional tree health assessment can help identify contributing factors and recommend treatment options.

Early identification can help prevent widespread infection and reduce stress on affected trees. Healthy trees are typically much better equipped to tolerate Powdery Mildew and recover from infections.

At CBM Tree Service, tree health assessments can help identify Powdery Mildew and other tree diseases, allowing property owners to take proactive steps to maintain healthy, attractive trees throughout the Texas Hill Country and Highland Lakes region. 

Texas Root Rot, also known as Cotton Root Rot, is a highly destructive fungal disease caused by Phymatotrichopsis omnivora. It is one of the most serious root diseases found in Texas and is responsible for the decline and death of thousands of trees, shrubs, and landscape plants each year.

The fungus lives naturally in many Texas soils, particularly in areas with alkaline, clay-rich soils. Once it infects a tree's root system, it prevents the roots from properly absorbing water and nutrients, often causing rapid decline and death.

• Live Oak
• Red Oak
• Cedar Elm
• Ash
• Pecan
• Chinese Pistache
• Fruit Trees
• Ornamental Shrubs
• Many hardwood species

Texas Root Rot often appears during the hot summer months when trees are under stress.

Common symptoms include:

• Sudden wilting of leaves
• Leaves turning yellow, bronze, or brown
• Rapid canopy decline
• Branch dieback
• Leaves remaining attached after death
• Entire sections of the tree dying quickly
• Root decay and deterioration

One of the most distinctive characteristics of Texas Root Rot is how quickly symptoms can develop. A tree that appeared healthy may decline dramatically within a few days or weeks.

The fungus thrives in:

• Alkaline soils
• Heavy clay soils
• Warm soil temperatures
• Drought-stressed conditions
• Areas with a history of infected plants

The pathogen can survive in the soil for many years, even after infected trees are removed.

As the disease destroys the root system, trees lose their ability to absorb moisture and nutrients. This can result in:

• Rapid tree death
• Increased susceptibility to storm damage
• Loss of valuable landscape trees
• Expensive removal and replacement costs
• Potential safety hazards from dead trees

Unfortunately, there is no proven cure for trees that are heavily infected.

Management strategies may include:

• Maintaining proper tree health
• Deep watering during drought periods
• Reducing root stress
• Improving soil conditions when possible
• Monitoring nearby trees for symptoms
• Removing dead or hazardous trees

• Avoid damaging tree roots
• Water trees during extended dry periods
• Protect trees during construction projects
• Maintain healthy soil conditions
• Schedule regular tree health inspections
• Plant resistant species in known problem areas

Removal may be necessary when:

• The tree has died
• Severe decline is present
• Structural stability is compromised
• The tree poses a risk to people or property
• Root failure is suspected

Because Texas Root Rot can progress rapidly, early recognition of symptoms is important. Identifying the disease early can help property owners evaluate nearby trees, reduce hazards, and make informed decisions about long-term landscape management.

At CBM Tree Service, tree health assessments can help identify Texas Root Rot and other root diseases before they become major safety concerns, helping property owners protect their trees and property throughout the Texas Hill Country and Highland Lakes region. 

Laminated Root Rot is a serious fungal disease caused by Phellinus sulphurascens (formerly Phellinus weirii). The disease attacks the root systems of trees, causing decay, loss of structural support, and eventual tree decline or death. It is most commonly associated with conifer forests in the western United States, but root decay fungi with similar characteristics can affect trees in a variety of environments.

The fungus spreads from tree to tree through root contact and can remain active in infected stumps and roots for decades.

• Douglas-fir
• True firs
• Spruce
• Hemlock
• Pine species
• Other coniferous trees

Because the disease develops underground, symptoms often appear gradually.

Common signs include:

• Thinning canopy
• Yellowing or pale foliage
• Reduced growth
• Sparse needle production
• Branch dieback
• Dead tops
• Leaning trees
• Wind-thrown trees
• Clusters of declining trees

The disease gets its name from the way infected wood separates into thin layers or sheets. When decayed roots are broken apart, the wood often appears laminated or layered.

The fungus attacks structural roots and causes:

• Root decay
• Loss of root strength
• Reduced water uptake
• Nutrient deficiencies
• Poor tree stability

As decay progresses, trees become increasingly vulnerable to wind damage and failure.

Laminated Root Rot primarily spreads through:

• Root-to-root contact
• Infected stumps
• Decaying root systems left in the soil

Unlike many fungal diseases, it does not rely heavily on airborne spores to infect new trees.

The disease can cause:

• Sudden tree failure
• Root plate failure
• Tree blowovers during storms
• Long-term decline of tree stands
• Increased safety risks near homes, roads, and recreational areas

Many affected trees may appear relatively healthy until significant root loss has occurred.

Unfortunately, there is no cure for Laminated Root Rot once a tree becomes infected.

Management strategies may include:

• Tree health assessments
• Monitoring tree stability
• Removal of infected trees
• Removal of infected stumps when practical
• Replanting with resistant species
• Long-term site management

• Avoid injuring tree roots
• Remove infected stumps when feasible
• Maintain overall tree health
• Monitor groups of trees for signs of decline
• Schedule routine tree inspections
• Address hazardous trees promptly

Removal may be recommended when:

• Significant root decay is present
• Trees become unstable or begin leaning
• Extensive canopy decline occurs
• Trees are located near structures or high-use areas
• Root failure is likely

Since Laminated Root Rot develops below ground, symptoms are often overlooked until substantial damage has occurred. Early identification can help reduce safety risks, protect nearby trees, and guide long-term property management decisions.

At CBM Tree Service, tree health assessments can help identify root-related problems, evaluate tree stability, and provide recommendations to help protect your property and maintain healthy, safe trees.

Polyporus squamosus, commonly known as Dryad's Saddle or Pheasant Back Mushroom, is a wood-decaying fungus that grows on living and dead hardwood trees. While it is best known for producing large, distinctive shelf-like mushrooms, its presence can indicate internal wood decay within the trunk or major branches.

This fungus is found throughout much of the United States, including Texas, where it commonly appears during spring and early summer following periods of rain.

• Elm
• Maple
• Cottonwood
• Sycamore
• Boxelder
• Willow
• Ash
• Other hardwood species

The fruiting body (mushroom) is often easy to identify because it has:

• Large shelf-shaped growths
• Tan to cream-colored caps
• Dark brown scales on the upper surface
• A pattern resembling pheasant feathers
• White pores underneath instead of gills
• Sizes ranging from a few inches to over 20 inches across

Young mushrooms often have a fresh cucumber or watermelon rind scent.

Trees affected by Polyporus squamosus may show:

• Shelf-like mushrooms growing from the trunk
• Fungal growth on large branches
• Internal wood decay
• Cavities within the trunk
• Dead or declining branches
• Structural weakness
• Hollow sections of wood

The fungus feeds on wood fibers and causes a type of decay known as white rot. As decay progresses, the structural strength of the affected wood decreases.

Potential concerns include:

• Branch failure
• Trunk decay
• Hollowing of the tree
• Increased storm damage risk
• Reduced structural stability

Not necessarily.

Some trees can live for years while hosting Polyporus squamosus. However, the appearance of mushrooms indicates that decay is already present somewhere inside the tree. The extent of decay can vary from minor to severe.

There is no fungicide that eliminates internal wood decay once it has become established.

Management typically focuses on:

• Monitoring tree health
• Evaluating structural stability
• Pruning hazardous limbs
• Inspecting cavities and decay areas
• Reducing tree stress
• Removing hazardous trees when necessary

• Avoid unnecessary trunk injuries
• Make proper pruning cuts
• Remove broken limbs promptly
• Protect trees during construction activities
• Maintain proper watering and mulching practices
• Schedule routine tree inspections

Removal may be recommended when:

• Extensive internal decay is present
• Large cavities compromise structural integrity
• Major limbs show signs of failure
• The tree is located near structures, vehicles, or high-use areas
• A professional assessment determines the risk is unacceptable

The mushrooms produced by Polyporus squamosus are often the first visible sign of internal decay. Identifying the fungus early can help property owners assess potential hazards and make informed decisions about tree preservation or removal.

At CBM Tree Service, tree health assessments can help identify decay fungi such as Polyporus squamosus, evaluate structural risks, and provide recommendations to help protect your trees and property.

Rust fungi are a group of plant diseases caused by various fungi in the order Pucciniales. These fungi affect the leaves, stems, needles, and sometimes fruits of trees and other plants. Rust diseases are named for the distinctive orange, yellow, reddish-brown, or rust-colored spores they produce on infected plant tissues.

While rust fungi rarely kill mature trees outright, severe or repeated infections can weaken trees, reduce growth, cause premature leaf drop, and increase susceptibility to drought, insects, and other diseases.

• Cedar (Juniper)
• Hawthorn
• Crabapple
• Pear
• Apple
• Quince
• Mesquite
• Cottonwood
• Poplar
• Various ornamental trees and shrubs

One of the most recognized rust diseases in Texas.

Hosts:

• Eastern Red Cedar
• Ashe Juniper
• Apple Trees
• Crabapple Trees

Hosts:

• Cedar Trees
• Hawthorn Trees

Hosts:

• Junipers
• Quince
• Pear
• Hawthorn

Common symptoms include:

• Orange, yellow, or rust-colored leaf spots
• Raised spore-producing structures
• Premature leaf drop
• Distorted leaves
• Swollen twigs or stems
• Reduced fruit production
• Stunted growth

On juniper trees, rust fungi often produce distinctive gelatinous orange structures after spring rains.

Rust fungi thrive under:

• Humid conditions
• Frequent rainfall
• Cool to moderate temperatures
• Poor air circulation
• Dense plantings

Many rust fungi require two different host plants to complete their life cycle.

Severe infections can lead to:

• Reduced photosynthesis
• Premature defoliation
• Decreased tree vigor
• Poor fruit quality
• Increased susceptibility to environmental stress

Young or already stressed trees are often affected most severely.

Rust spores spread through:

• Wind
• Rain splash
• Infected plant material
• Seasonal spore release

Spores can travel significant distances between host plants.

Yes. Management options may include:

• Pruning infected branches
• Improving air circulation
• Removing alternate host plants when practical
• Fungicide applications for high-value trees
• Proper watering and fertilization
• Routine tree health monitoring

• Maintain proper tree spacing
• Improve canopy airflow through pruning
• Remove heavily infected plant material
• Water at the base of plants when possible
• Promote overall tree health
• Schedule regular tree inspections

Professional evaluation may be beneficial when:

• Trees lose leaves repeatedly each year
• Large portions of the canopy are affected
• Rust infections spread rapidly
• Valuable ornamental or fruit trees are involved
• Tree health continues to decline

Rust fungi are often easiest to manage during the early stages of infection. Identifying symptoms early can help reduce disease spread, preserve tree vigor, and improve the long-term health of your landscape.

At CBM Tree Service, tree health assessments can help identify rust fungi and other tree diseases, allowing property owners to take proactive steps to protect valuable trees throughout the Texas Hill Country and Highland Lakes region.

Pecan Scab is the most common and economically important disease affecting pecan trees in Texas and across the southeastern United States. It is caused by the fungus Venturia effusa (formerly Fusicladium effusum), which infects young leaves, shoots, twigs, and developing pecans.

The disease thrives during warm, humid weather and can significantly reduce both the quality and quantity of pecan production if left unmanaged.

Pecan Scab primarily affects:

• Native pecan trees
• Improved pecan cultivars
• Orchard-grown pecans
• Landscape pecan trees

Some pecan varieties are naturally more resistant than others.

Common symptoms include:

• Small olive-green to black spots on leaves
• Dark, velvety lesions on young shoots
• Black spots on developing pecan shucks
• Premature nut drop
• Misshapen or undersized pecans
• Defoliation during severe infections
• Reduced tree vigor over time

As the disease progresses, the spots enlarge and may merge, covering large portions of leaves or nuts.

The fungus spreads through:

• Wind-blown spores
• Rain splash
• Extended periods of leaf wetness
• Warm, humid spring and summer weather
• Infected leaves, twigs, and shucks remaining in the orchard

New growth is especially susceptible to infection.

The disease is most likely to develop when:

• Temperatures range from 70°F to 85°F
• Relative humidity is high
• Frequent rainfall or irrigation wets the foliage
• Dense tree canopies reduce air circulation
• Trees remain wet for several hours

Wet springs and humid summers often lead to severe outbreaks.

Pecan Scab can:

• Reduce nut size and quality
• Cause premature nut loss
• Lower overall yields
• Reduce photosynthesis through leaf damage
• Weaken trees after repeated severe infections
• Decrease the market value of pecans

Commercial orchards can experience substantial crop losses if the disease is not managed.

Yes. The disease can often be managed with an integrated approach that includes:

• Planting resistant pecan varieties
• Pruning to improve sunlight penetration and air circulation
• Removing infected plant debris when practical
• Avoiding excessive nitrogen fertilization that promotes dense foliage
• Applying preventive fungicide sprays during the growing season when conditions favor disease development

Preventive treatments are generally more effective than treating after symptoms become severe.

• Choose scab-resistant pecan cultivars whenever possible.
• Prune trees to maintain an open canopy.
• Monitor trees regularly during warm, wet weather.
• Avoid overhead irrigation that keeps leaves wet for extended periods.
• Clean up fallen leaves and infected shucks when practical.
• Maintain proper watering and fertilization to support overall tree health.

Pecan Scab spreads quickly during favorable weather, and early infections can affect the entire growing season. Identifying symptoms early and beginning appropriate management can help protect developing nuts, maintain healthy foliage, and improve long-term tree productivity.

In Texas, regular inspections during the spring and summer are especially important, as warm temperatures and periodic rainfall create ideal conditions for Pecan Scab to develop.