Important Tree Diseases in the North Carolina Piedmont Area

Unfortunately, several diseases threaten the trees of the North Carolina Piedmont. 

Some are relatively mild, self-limiting, and likely to resolve on their own, while others can kill even healthy, mature trees in a matter of weeks. Most fall somewhere in between these two extremes, meaning that they may recover with proper treatment or at least remain safe when appropriately managed. 

That’s why it is important for homeowners and property managers to learn about the most noteworthy tree diseases in our area. By spotting the earliest signs of trouble, you can secure professional assistance and give yourself the best chance of avoiding unnecessary removals or preventing diseases from spreading. 

We’ll try to help you do exactly that below, by outlining some of the most notable tree diseases in the North Carolina Piedmont. 

Important Tree Diseases in North Carolina

Tree diseases can be categorized in a number of ways. You could, for example, group them by host species, taxonomic arrangement, or severity. But we’ll group them by how the pathogen affects the tree and the tissues or structures it primarily attacks.

Note that this list is far from exhaustive — there are dozens of other tree diseases that affect the trees of the North Carolina Piedmont. These are simply a few of the ones area residents should be aware of. 

Vascular & Wilt Diseases

Several tree diseases affect the host’s vascular system, making it difficult for the tree to transport water and nutrients. This often results in wilting foliage, as well as other symptoms. 

A few of the most important wilt and vascular diseases in our area include: 

Bacterial Leaf Scorch (Xylella fastidiosa)

This disease disrupts water movement through the vascular system. It most commonly affects oaks (Quercus spp.), elms (Ulmus spp.), and sycamores (Platanus spp.), but it can also infect other hardwoods. Symptoms typically begin as browning along leaf margins and may progress to branch dieback and canopy decline.

Dutch Elm Disease (Ophiostoma spp.)

This destructive fungal disease affects elm trees and is primarily spread by elm bark beetles and through root grafts between nearby trees. Infected trees typically develop wilting, yellowing or browning foliage and progressive branch dieback as the fungus interferes with water transport.

Verticillium Wilt (Verticillium spp.)

Verticillium wilt is a soilborne fungal disease that affects maples (Acer spp.) and redbuds (Cercis spp.), as well as many other hardwood trees and shrubs. Symptoms can include wilting, leaf scorch, stunted growth, branch dieback, and characteristic discoloration of the vascular tissue beneath the bark.

Oak Wilt (Bretziella fagacearum)

Though not as common in eastern North Carolina as it is in the western portion of the state, oak wilt is a serious vascular disease to be aware of. Symptoms can include leaf discoloration, wilting, leaf drop, canopy thinning, and dieback, with members of the red oak group generally declining more rapidly than white oaks.

Canker & Bark Diseases

Given that the primary job of bark is to protect a tree from the outside world, it’s easy to see how bark diseases and cankers — sunken lesions that may exude fluid or grow over time — can sometimes present a serious threat. 

Some of the most noteworthy bark and canker diseases in North Carolina include:  

Biscogniauxia (Hypoxylon) Canker (Biscogniauxia atropunctata)

This fungal disease primarily affects stressed hardwoods, especially oaks weakened by drought or other environmental problems. Infected trees may develop thinning canopies, branch dieback, patches of sloughing bark, and distinctive dark fungal tissue on exposed wood.

Botryosphaeria Canker (Botryosphaeria spp.)

Botryosphaeria canker affects a variety of hardwood trees and shrubs, and it is particularly likely to cause problems in plants already experiencing environmental stress. Symptoms can include sunken or discolored bark, branch dieback, wilting foliage, and cankers that expand along affected stems and branches.

Nectria Canker (Neonectria spp.)

Nectria canker affects a variety of hardwood trees and typically enters through wounds or damaged bark. Infections produce sunken or callused cankers that may expand over time and cause branch dieback when they girdle affected stems and choke off the flow of water and nutrients.

Cytospora Canker (Cytospora spp.)

Cytospora canker is associated with numerous trees, but it is most common in those weakened by drought, injury, or unfavorable growing conditions. Symptoms may include sunken or discolored bark, resin or sap production on some hosts, and progressive dieback of infected branches.

Seiridium Canker (Seiridium spp.)

Seiridium canker is an important disease of Leyland cypress (× Cuprocyparis leylandii) and several other conifers, particularly when trees are stressed by drought or poor growing conditions. It causes elongated cankers on stems and branches, often accompanied by resin flow and the death of individual branches.

Pitch Canker (Fusarium circinatum)

Pitch canker is a fungal disease of pines (Pinus spp.) that produces resinous cankers on branches, trunks, and shoots. Infected portions of the tree may develop needle discoloration and dieback, while severe infections can cause extensive canopy decline.

Thousand Cankers Disease (Geosmithia morbida)

Though not established in the North Carolina Piedmont, thousand cankers disease is something local residents should be aware of. It primarily affects black walnut (Juglans nigra) and causes numerous small cankers to develop beneath the bark, eventually disrupting vascular function and causing branch dieback.

Root & Belowground Diseases

Diseases affecting a tree’s roots are often particularly troubling, as they can not only inhibit a tree’s ability to transport water and nutrients, but they can also reduce the tree’s anchorage and stability. 

A few of the most important root-related diseases in the North Carolina Piedmont include:

Armillaria Root Rot (Armillaria spp.)

Armillaria root rot affects a wide range of trees and is often most damaging to trees already weakened by drought, injury, or other stresses. Symptoms can include canopy thinning, branch dieback, white fungal growth beneath the bark, dark rootlike rhizomorphs, and clusters of mushrooms near the tree’s base.

Phytophthora Root Rot (Phytophthora spp.)

Phytophthora root rot is caused by soilborne water molds that are especially problematic in wet, poorly drained soils. Infected trees may develop damaged or decaying roots, reduced growth, yellowing or wilting foliage, canopy thinning, and progressive dieback.

Heterobasidion Root Disease (Heterobasidion irregulare)

This fungal disease primarily affects pines and often becomes established when airborne spores infect freshly cut stumps, allowing the fungus to spread through interconnected root systems. Affected trees may exhibit reduced growth, thinning crowns, foliar discoloration, root decay, and an increased risk of windthrow.

Twig & Foliar Diseases 

Twig and foliar diseases often cause fairly obvious symptoms, ranging from foliar discoloration to premature leaf drop to crown dieback. Their severity varies considerably; some cause little lasting harm, while others may prove fatal in a matter of weeks.  

Some of the most notable twig and foliar diseases we see in North Carolina include: 

Anthracnose (Apiognomonia, Discula spp., and others)

Anthracnose refers to a group of fungal diseases that affect the leaves, shoots, and twigs of sycamores, oaks, maples, dogwoods (Cornus spp.), and many other hardwoods. Symptoms commonly include irregular brown or black leaf lesions, distorted foliage, premature leaf drop, and, in some hosts, twig dieback.

Powdery Mildew (various fungi)

Powdery mildew is a group of fungal diseases recognizable by the white or gray powdery growth that develops on leaves and young shoots. Although usually more unsightly than dangerous, severe infections can cause distorted foliage, premature leaf drop, and reduced growth.

Tubakia Leaf Spot (Tubakia spp.)

Tubakia leaf spot is a common fungal disease of oaks that produces brown to reddish-brown spots or blotches on the foliage. Infections are often most noticeable late in the growing season and may cause premature leaf drop in severe cases.

Cercospora Leaf Spot (Cercospora spp.)

Cercospora fungi cause leaf spot diseases on a wide variety of trees and shrubs, typically producing small brown, tan, gray, or purplish lesions. Heavy infections can cause lesions to merge, resulting in extensive discoloration and premature leaf drop.

Cedar-Apple/Cedar-Hawthorn Rusts (Gymnosporangium spp.)

These rust diseases require both junipers (Juniperus spp.) and susceptible members of the rose family, such as apples (Malus spp.) and hawthorns (Crataegus spp.), to complete their life cycles. They can produce conspicuous orange growths on junipers and yellow-orange leaf spots or leaf drop on deciduous hosts.

Fire Blight (Erwinia amylovora)

Fire blight is a bacterial disease affecting pears (Pyrus), apples, hawthorns, and other members of the rose family. Infected flowers and shoots rapidly wilt and darken, often producing the characteristic curved “shepherd’s crook” appearance at the tips of affected shoots.

Wood & Structural Decay Diseases

Unfortunately, many tree diseases that affect the xylem (wood) tissue produce very few visible signs or symptoms. Meanwhile, the pathogen may be compromising the tree’s structural integrity, putting it at increased risk of catastrophic failure. 

A few of the most important tree diseases that affect the wood or lead to structural decay include:

Ganoderma Butt/Root Rot (Ganoderma spp.)

Ganoderma fungi cause white rot of roots and lower trunk wood in a wide variety of hardwood trees. Infected trees may develop shelf-like conks near the base, while advanced internal decay can weaken structural roots or the lower trunk and increase the likelihood of failure.

Inonotus/Pseudoinonotus Heart Rot (Inonotus/Pseudoinonotus spp.)

These fungi cause internal wood decay in oaks and various other hardwoods, often entering through wounds or dead branch stubs. Fruiting bodies may appear on trunks or branches, while extensive internal decay can reduce wood strength even when the surrounding canopy appears relatively healthy.

Laetiporus Brown Rot (Laetiporus spp.)

Laetiporus fungi cause brown rot of the heartwood and are commonly associated with mature oaks and other hardwoods. Their distinctive orange-to-yellow shelf-like fruiting bodies can indicate extensive internal decay that may significantly reduce the strength of affected wood.

Kretzschmaria Root/Butt Decay (Kretzschmaria deusta)

Kretzschmaria decay — also called brittle cinder fungus — causes damage to the roots and lower trunks of many hardwood trees, especially beeches (Fagus spp.) and maples. Fruiting structures typically appear near the base as grayish patches that mature into hard, black crusts.

Trametes Decay (Trametes spp.)

Trametes fungi cause white rot in the wood of many hardwood species and commonly colonize dead, damaged, or weakened tissues. Thin, shelf-like fruiting bodies may develop on affected wood, while the underlying decay gradually reduces wood strength.

Pleurotus Heartwood Decay (Pleurotus spp.)

Pleurotus fungi can colonize dead or compromised wood within living hardwood trees and cause white rot of the heartwood. Clusters of oyster-like mushrooms on a trunk or major branch can indicate internal decay that may warrant further evaluation, particularly when structural components are affected.

Distinguishing Tree Stress from Tree Disease

It’s important to note that tree diseases are not the same thing as general tree decline. 

Infectious diseases are caused by pathogens (typically bacteria, fungi, or other microorganisms), whereas decline is often caused by abiotic (non-living) factors. 

Some of the most common sources of tree stress in the North Carolina Piedmont include:

• Drought and prolonged periods of hot, dry weather
• Excessive soil moisture or poor drainage
• Compacted or disturbed soil
• Construction damage and root loss
• Improper planting or excessive mulch
• Nutrient deficiencies or unfavorable soil conditions
• Herbicide exposure or other types of chemical injury

It’s important to note that stress, particularly long-term or severe stress, can kill trees just like diseases can. As is the case with diseases, prompt care and management can make all the difference between a tree that recovers and one that continues to spiral downward. 

So, while it isn’t always easy to determine whether stress or disease is affecting your trees, there are a few things you can consider when trying to distinguish between the two. 

It is, however, important to note that stress and disease often occur together. 

A tree weakened by drought, root damage, or poor growing conditions may become more susceptible to some pathogens. Biscogniauxia (hypoxylon) canker, for example, is frequently associated with oaks already experiencing significant environmental stress.

That’s why it’s important to partner with an arboricultural team who can properly assess your trees and look beyond individual symptoms to develop a comprehensive support plan for your tree.  

Tree Diseases in North Carolina: Frequently Asked Questions

The sight of a stressed or diseased tree can leave homeowners and property managers with a number of questions. We’ll answer a few of the most common ones we hear from our clients below, to help you know what to expect.  

What are the most common tree diseases in the North Carolina Piedmont?

Common tree diseases in the region include bacterial leaf scorch, anthracnose, powdery mildew, various leaf spots, canker diseases, Armillaria root rot, Phytophthora root rot, and several types of wood decay.  

How can I tell if my tree has a disease?

Watch for things like unusual leaf discoloration or spotting, wilting, premature leaf drop, thinning foliage, branch dieback, bark lesions, cankers, fungal growth, or fruiting bodies. 

Just note that these symptoms don’t always indicate disease; they can also be caused by drought, root damage, compacted soil, and other environmental stresses, helping to illustrate the importance of having a professional arborist evaluate your trees at the first sign of trouble. 

Can a diseased tree be saved?

Sometimes. The prognosis will typically depend on the disease, how far it has progressed, the tree species, and the tree’s overall condition. In all cases, early diagnosis will provide the greatest number of management and treatment options.

Do tree diseases spread from one tree to another?

Some do, but the way they spread varies considerably. Pathogens may be carried by wind, rain, contaminated tools, insects, soil, or infected plant material. Other diseases are opportunistic and primarily affect trees already weakened by drought, injury, or other stresses.

Should I use a fungicide on a diseased tree?

Not without identifying the problem first. Fungicides only work against certain fungal diseases, and many are most effective when applied preventively rather than after extensive symptoms develop. They will not treat bacterial diseases, existing wood decay, pest infestations, or problems caused by environmental stress.

Can drought or other stress make tree diseases worse?

Yes. Drought, flooding, root damage, soil compaction, and other stresses can weaken a tree’s natural defenses, thereby increasing its susceptibility to some diseases. In some cases, improving the tree’s growing conditions and reducing stress are important parts of disease management.

When should a diseased tree be removed?

Removal may be appropriate when a disease has caused extensive decline, cannot reasonably be managed, or has compromised the structural integrity of the tree. Trees with significant root, trunk, or structural wood decay deserve particular attention because declining wood strength can increase the likelihood of failure.

When should I have an arborist look at a potentially diseased tree?

It’s always wise to have an arborist evaluate trees displaying any concerning symptoms. This is especially important when the symptoms are severe, continue to worsen, or affect major branches or the trunk.  

Protect Your Piedmont Trees with Expert Disease Care

Tree diseases do not always represent a death sentence or necessitate removal, but it’s important to get professional help early, as this will provide the greatest number of treatment and management options. 

If you’re concerned about a tree on your North Carolina property, schedule an evaluation with the Lubbers & Sons Tree Care team. We’ll assess the tree, identify the likely cause of the problem, and recommend an appropriate course of action. 

Sources & References

• USDA Forest Service – “Forest Health Highlights in North Carolina 2025”
  Annual federal forest health report summarizing the year’s insect, disease, and abiotic damage trends across North Carolina forests, including major pests such as hemlock woolly adelgid and emerging threats.
  https://www.fs.usda.gov/foresthealth/docs/fhh/NC_FHH_2025.pdf
• NC State Extension – “Common Disease Pests of Maple in North Carolina”
  Diagnostic factsheet on the diseases that most often affect maples in North Carolina, with symptoms and management guidance for landscape trees.
  https://content.ces.ncsu.edu/common-disease-pests-of-maple-in-north-carolina
• NC State Extension – “Common Disease Pests of Oak in North Carolina”
  Diagnostic factsheet describing frequent oak diseases such as oak leaf blister, bacterial leaf scorch, and anthracnose, with symptom images and links to detailed guidance.
  https://content.ces.ncsu.edu/common-disease-pests-of-oak-in-north-carolina
• NC State Extension – “Diseases of Dogwood in North Carolina”
  Extension factsheet on the major dogwood diseases in North Carolina, including dogwood anthracnose (Discula destructiva), with identification and management information.
  https://content.ces.ncsu.edu/diseases-of-dogwood-in-north-carolina
• NC State Extension – “Cedar Apple Rusts”
  Extension factsheet on cedar apple rust (Gymnosporangium juniperi-virginianae), covering its alternating life cycle between juniper and apple or crabapple hosts and options for managing it.
  https://content.ces.ncsu.edu/cedar-apple-rusts
• North Carolina Forest Service – “Thousand Cankers Disease”
  State forestry agency page on thousand cankers disease of walnut, caused by Geosmithia morbida and spread by the walnut twig beetle (Pityophthorus juglandis), with North Carolina’s detection and response information.
  https://www.ncagr.gov/divisions/nc-forest-service/Thousands-Cankers-Disease
• North Carolina Forest Service – “Common Forest Diseases”
  State forestry overview of the tree diseases most frequently encountered in North Carolina forests and landscapes.
  https://www.ncagr.gov/divisions/nc-forest-service/forest-health/common-forest-diseases
• Arbor Day Foundation – “Health Issues”
  Nonprofit tree-care resource covering common tree health problems and general guidance for recognizing and addressing them.
  https://www.arborday.org/tree-care-maintenance/health-issues