Oak Diseases and Insect Pests in South Carolina

Oak trees in South Carolina are susceptible to fungal diseases, bacterial infections, parasitic plants, and insect pests.

Proper identification of oak diseases and insect pests is essential for effective management in South Carolina landscapes. This fact sheet outlines identification, prevention, and management strategies for common oak health problems.

Quick Guide: Oak Diseases and Insect Pests in South Carolina

Affected Plants:

• Oak species (Quercus spp.) grown in South Carolina

Primary Disease Types:

• Fungal diseases (e.g., oak leaf blister, powdery mildew, Armillaria root rot, Hypoxylon canker, Actinopelte leaf spot, pine-oak gall rust)
• Bacterial disease (bacterial leaf scorch)

Primary Insect Pests:

• Galls (various insects & mites)
• Oakworms (Anisota spp.)
• Scale insects (including oak lecanium scale, Parthenolecanium quercifex)

Primary Causes:

• Fungal pathogens
• Bacterial infection (Xylella fastidiosa)
• Insect feeding
• Environmental stress (especially drought and root injury)

Most Important Prevention Strategy:

Maintain tree health through proper watering, mulching, fertilization, and protection from root and construction damage

Chemical Control:

Often limited or impractical on large trees; specific fungicides and insecticides listed in Table 1; horticultural oil recommended for scale management

Although many oak species (Quercus) are well adapted to South Carolina, they may still be affected by a variety of insect pests and diseases.

Always maintain healthy oak trees by following recommended cultural practices, which are the first line of defense in preventing most of these problems. For more information, see HGIC 1017, Oak.

Oak Diseases in South Carolina

Oak trees in South Carolina are affected by fungal, bacterial, and stress-related diseases.

Oak Diseases: Oak Leaf Blister on Oak

Oak leaf blister is a fungal disease affecting oak species in South Carolina.

Cause

Oak leaf blister is a disease caused by the fungus Taphrina caerulescens. Most oak species are susceptible, but the red and black oak groups are especially so.

The fungus survives the winter as spores in leaf buds. The spores germinate in the spring, infecting the leaves. The fungus grows and produces spores within the leaf until the cuticle (surface wax layer) is ruptured by the mass of fungal tissue. Spore dispersal occurs in the fall.

Substances secreted by the fungus cause infected leaf tissue to grow much faster than uninfected tissue, resulting in distorted blisters.

Signs

• No obvious signs

Symptoms

• Blister-like patches appear on the leaves
• Blisters are often lighter green than the surrounding tissue
• Patches later turn brown
• The blister-like patches result from an overgrowth of infected leaf tissue caused by substances secreted by the fungus
• Minor infections cause little harm
• Severe infections may cause midsummer defoliation

Prevention & Treatment

Cultural Controls

• Rake up and dispose of fallen leaves in the fall

Leaf blister is rarely severe enough to require control measures.

Chemical Control

• Once an infection has occurred, fungicide treatments are usually ineffective.
• If the infection is very heavy and the tree is small enough to achieve good coverage, a fungicide could be applied in the spring, just before bud break.

Oak Diseases: Bacterial Leaf Scorch on Oak

Bacterial leaf scorch is a chronic vascular disease that disrupts water movement in oak trees.

Cause

Bacterial leaf scorch is caused by the xylem-limited bacterium Xylella fastidiosa. The disease disrupts water movement within the tree.

Leafhoppers and spittlebugs spread the bacterium.

Signs

• No obvious signs

Symptoms

• Marginal reddening or yellowing of leaves
• Browning of leaf margins
• Leaf drop
• Dieback
• Gradual decline and eventual death

The symptoms usually first appear in early fall, following summer drought. Because trees infected with bacterial leaf scorch decline gradually, it may take five to ten years before a tree needs to be removed.

This disease commonly affects:

Oaks

• Bur oak
• Pin oak
• Red oak
• Shingle oak
• White oak

Other trees

• Elm
• Hackberry
• Red, silver, and sugar maples
• Sweetgum
• Sycamore

Prevention & Treatment

Cultural Controls

• Remove infected trees and replant the area with resistant tree species
• Avoid planting all the same species close together
• Control weeds and wild plants that support leafhoppers and spittlebugs
• Provide fertilizer and irrigation to prolong the infected tree’s life
• Trees with extensive leaf scorch and dieback should be removed

Chemical Control

• Currently, spray treatments are not available
• Certified arborists can perform annual root flare injections of oxytetracycline (such as Bacastat) to reduce symptoms by suppressing the pathogen

Oak Diseases: Actinopelte Leaf Spot on Oak

Actinopelte leaf spot is a fungal leaf disease that commonly affects oaks during wet weather.

Cause

Actinopelte leaf spot is a fungal disease caused by Tubakia dryina (formerly called Actinopelte dryina). This fungal disease may be a serious problem in wet weather.

Signs

• No obvious signs

Symptoms

• Circular, dark to reddish-brown leaf spots
• Spots measure ¼ to ½ inch in diameter
• Spots may merge to form irregular blotches
• Tiny black specks appear in rings within the spots and blotches
• Severe infections cause premature leaf drop

Trees of low vigor that are repeatedly defoliated may die.

Prevention & Treatment

Cultural Controls

• Destroy infected plant material to reduce spread
• Rake up and dispose of fallen leaves

Small trees defoliated for several years in a row may need fungicide applications

Chemical Control

Fungicides for control include:

• Mancozeb
• Chlorothalonil
• Thiophanate-methyl
• Copper

Complete coverage is necessary for control.

Apply fungicides according to the label instructions. See Table 1 for examples of specific fungicide products.

Oak Diseases: Powdery Mildew on Oak

Powdery mildew is a fungal disease that produces white growth on oak leaves.

Cause

Several fungi, including Erysiphe trina, Microsphaera alni, Phyllactinia corylea, and Sphaerotheca lanestris, cause powdery mildew.

Signs

• White, powdery growth on both leaf surfaces
• Grayish-white fungal growth may turn tan, then brown with age
• Tiny black dots (fungal fruiting bodies) may be visible in some years

Symptoms

• Foliage may be malformed
• Premature leaf drop
• Leaves may dry out and shrivel

Prevention & Treatment

Cultural Controls

Control is usually not practical nor warranted.

Chemical Control

• Myclobutanil or thiophanate-methyl sprays may be used to control powdery mildew in severe cases and on small trees
• Follow the directions on the label
• See Table 1 for examples of specific products

Oak Diseases: Armillaria Root Rot on Oak

Armillaria root rot is a soilborne fungal disease that causes gradual decline in oak trees.

Cause

Armillaria root rot, caused by the fungus Armillaria mellea, is widespread on oak trees.

Signs

• Mushroom fruiting structures on or near the root collar
• Honey-colored mushrooms appear in clusters outward from the tree following major roots

Mushroom fruiting structures are prevalent, especially during wet weather.

Symptoms

• Slow decline of the tree
• Reduced vigor
• Symptoms are most noticeable in late summer and fall

Prevention & Treatment

Cultural Controls

• Remove diseased trees and as much of the root system as possible
• Do not replant the site with a susceptible host

Armillaria root rot-resistant or tolerant trees include:

• Bald-cypress (Taxodium distichum)
• Chinese elm (Ulmus parvifolia)
• Dawn redwood (Metasequoia glyptostroboides)
• Eucalyptus
• Ginkgo (Ginkgo biloba)
• Japanese cedar (Cryptomeria japonica)
• Leyland cypress (Cupressocyparis leylandii)
• Maple (Acer species)
• Sourwood (Oxydendrum arboreum)
• Sweetgum (Liquidambar styraciflua)

Chemical Control

There are no effective chemical controls.

Oak Diseases: Hypoxylon Canker on Oak

Hypoxylon canker is a stress-related fungal disease that attacks weakened oak trees, including:

• Post oak
• Water oak
• Southern red oak
• White oak
• Blackjack oak

Cause

Hypoxylon canker is a white-rot fungal disease caused by Biscogniauxia atropunctata var. atropunctata (formerly called Hypoxylon atropunctatum). It primarily affects oaks, hickories, and pecans in South Carolina.

This fungus is an opportunistic pathogen that commonly inhabits the bark of hardwood trees and becomes problematic when trees are under severe stress.

Environmental stress that weakens trees includes:

• Drought
• Root injury during construction or utility trenching
• Soil grade changes
• Soil compaction
• Root diseases

Drought stress appears to be the most significant factor in infection.

Signs

• Brownish fungal stroma exposed beneath bark
• Stroma may extend several inches to several feet on limbs and trunks
• Fungal stroma changes from brown to gray or silver and finally to black as the sexual stage develops

Conidia are wind-disseminated and can cause new infections on other trees. Sexual spores are spread by splashing rain or insects.

Symptoms

• Dying back of the crown (top) of the infected tree
• Outer bark begins to slough off in areas of infection
• Pieces of bark visible at the base of the tree

Note: These symptoms may resemble those caused by other tree problems, so careful diagnosis is important.

Prevention & Treatment

Cultural Controls

Stress reduction is the key to preventing infection:

• Protect trees from damage during construction and utility repairs
• Water trees during summer drought with 1 inch of irrigation water per week
• Mulch trees with a 3-inch layer of organic mulch from the trunk to the dripline, avoiding contact with the trunk
• Do not apply weed killers near the tree, especially beneath the limb canopy
• Fertilize trees with slow-release tree and shrub fertilizer during early April
• Remove and dispose of infected trees and cut remaining stumps flush with the soil

For additional guidance, see:

• HGIC 1002, Protecting Trees During Construction
• HGIC 1056, Watering Shrubs & Trees
• HGIC 1604, Mulch
• HGIC 1000, Fertilizing Trees & Shrubs

If the infection is observed on branches, they may be removed and burned, but other infection sites may not yet be apparent.

Chemical Control

There are no controls for Hypoxylon canker once the infection has begun on the trunk.

Oak Diseases: Pine-Oak Gall Rust on Oak

Pine-oak gall rust is a fungal disease that infects both pine and oak species.

Cause

Pine-Oak Gall Rust (Eastern Gall Rust) is caused by the fungus Cronartium quercuum on approximately 25 to 30 species of pine and oak.

Fungal spores are primarily windborne. High humidity increases the incidence of infection.

Signs

• Yellow to orange powder pustules (spores) on the underside of the leaves

Symptoms

• Small brown or yellowing areas on oak leaves

Prevention & Treatment

Chemical Control

Chemical control is usually not warranted.

• The fungicide myclobutanil may be applied to oaks according to the label directions
• See Table 1 for examples of specific products

Oak Diseases: Mistletoe on Oak

Mistletoe is a parasitic plant that attaches to oak branches and extracts water and minerals.

Cause

Mistletoe (Phoradendron species) is a parasitic plant that commonly infects oak trees. Although mistletoe obtains water and minerals from the tree, it does not depend totally on the host for food. Its green leaves contain chlorophyll, which helps produce carbohydrates.

Signs

• Clumps of green growth in the limb canopy after leaf drop in fall
• Small white berries

Mistletoe berries are highly toxic to humans. The stems and leaves are also toxic and may cause skin irritation in some people.

Symptoms

• Reduced vigor in heavily infested trees

Prevention & Treatment

Cultural Controls

• Cut out infected limbs 1 to 2 feet below the point of attachment
• In some instances, breaking out the tops of the mistletoe may be effective

Chemical Control

• Ethephon (Florel Brand Fruit Eliminator) is labeled for mistletoe control
• Large infestations may be difficult to control with a single spray application, and retreatment may be required
• Make applications after the fall leaf drop through mid-winter

Oak Diseases: Lichens on Oak

Lichens are symbiotic organisms that grow on oak bark but do not infect or harm the tree.

Cause

Lichens are organisms composed of a fungus and an alga and/or a cyanobacterium living together symbiotically. The alga converts sunlight and carbon dioxide to food (i.e., carbohydrates), while the fungus provides protection and structure.

Lichens typically appear on the trunk and branches of trees that are in poor health, but they are totally harmless and are in no way responsible for tree decline. As trees lose vigor and leaf density, more sunlight reaches the trunk and limbs, creating favorable conditions for lichen growth.

Signs

• Green to gray-green leafy or crusty growths on trunks and branches

Symptoms

• Growth is most noticeable on trees with sparse foliage

Note: Lichens are harmless and are not responsible for tree decline.

Prevention & Treatment

Cultural Controls

• Correct the underlying cause of decline to restore tree health
• As foliage growth increases, lichens will gradually disappear

Chemical Control

For dormant-season lichen control on tree trunks and limbs, products containing potassium salts of fatty acids can be used to manage lichens. These products are labeled for use only on hardened bark.

Available products include:

• Bonide Moss Max RTS¹
• Bayer BioAdvanced 2 in 1 Moss & Algae Killer & Cleaner RTS¹
• Scott’s MOSS-EX 3-in-1 RTS¹

These algae and moss killers also have lichens listed on the labels.

Oak Diseases: Spanish Moss on Oak

Spanish moss is an epiphytic plant that grows on oak limbs but does not parasitize the tree.

Cause

Spanish moss (Tillandsia usneoides) is an epiphytic plant that grows on other plants for support and protection. It does not feed directly on the host tree, but obtains water and nutrients from the air and rain.

Spanish moss is found only in warm, humid areas of South Carolina’s southern and coastal regions.

Signs

• Mass of long, gray-green filamentous growth hanging from limbs

Symptoms

• Heavy infestations may shade out lower leaves
• Large wet masses may increase limb weight
• Limb breakage under severe infestations

Spanish moss is commonly found on trees in decline. Heavy infestations may contribute to further decline due to shading and limb stress.

Prevention & Treatment

Cultural Controls

• Increase tree vigor through proper watering and fertilization
• Remove Spanish moss by hand when necessary

Chemical Control

No chemical controls

Oak Insect Pests in South Carolina

Several insects and related pests feed on oak foliage, stems, and roots in South Carolina.

Oak Insect Pests: Galls on Oak

Galls are irregular growths on oak caused by insect or mite activity.

Cause

Galls are irregular growths or swellings caused by feeding or egg-laying by various mites and insects. More galls occur on oak than on any other kind of plant. At least 750 different galls have been identified on oak.

Gall development is a reaction by plant tissue to feeding or egg-laying by insects or mites.

Signs

• No obvious signs

Symptoms

• Irregular swellings or growths
• Wide variation in size, shape, and location
• Most are unsightly
• Twig galls may kill individual limbs
• Severe twig gall infestations may kill the entire tree

Most galls do not seriously harm oak trees, but detract from the beauty of the tree.

 

Prevention & Treatment

Cultural Control

• Remove and destroy fallen leaves with galls
• Prune out twig galls while green or before emergence holes appear

Biological Control

Parasitic insects, birds, and animals naturally control many gall-producing insects and mites.

Chemical Control

In most cases, chemical control is impractical or ineffective, especially on large trees.

Oak Insect Pests: Oakworms on Oak

Oakworms are caterpillars that feed heavily on oak leaves.

Cause

Oakworms are the larvae (or caterpillars) of three closely related moth species:

• Anisota senatoria
• Anisota stigma
• Anisota virginiensis

The orangestriped oakworm (Anisota senatoria) is most common in South Carolina. In the fall, caterpillars crawl to the ground and burrow into the soil, overwinter (survive the winter) in the soil, and mature into adults (moths).

Moths appear in June and July, and the female moths lay clusters of eggs on the undersurfaces of oak leaves. Caterpillars reach their full size by early fall and are black with yellow or orange stripes running the length of their bodies.

Identification

• Mature length (2–3/16 inches)
• Distinctive two black “horns” (second segment behind the head)
• Orange or yellow longitudinal striping
• Group feeding behavior in early stages
• Seasonal appearance (June–July egg laying, midsummer feeding)

Signs

• Group feeding by small, greenish-yellow caterpillars
• Leaf blades eaten, leaving a lacy network of veins
• Mature caterpillars are solitary feeders
• Complete defoliation on small trees by midsummer

Symptoms

• Twig dieback may occur from sunscald on mature trees

Healthy trees can tolerate feeding, but repeated defoliation may weaken young trees.

 

Prevention & Treatment

Cultural Controls

• Handpick and destroy caterpillars on young trees during light infestations
• Rely on birds, parasites, and diseases for natural control

Biological Control

• Bacillus thuringiensis (B.t.) is a microbial insecticide effective against young larvae
• A safer alternative when spraying up into a tall tree.
• Follow label directions

Chemical Control

If chemical control becomes necessary on smaller trees, the following insecticides are labeled for control:

• Spinosad
• Permethrin
• Cyfluthrin
• Cyhalothrin
• Bifenthrin
• Acephate

See Table 1 for examples of specific products.

Oak Insect Pests: Scale on Oak

Scale insects are sap-feeding pests that attach to oak stems and leaves.

Cause

Various kinds of scale insects are pests of oak. Adult scale insects are unusual insects in appearance in that they are small, immobile, and have no visible legs. They vary in appearance depending on age, sex, and species.

Scales feed on sap by piercing the leaf or stem with their mouthparts and sucking plant sap.

Some scale insects (soft scales) excrete honeydew as they feed on plant sap. The sooty mold fungus grows on the honeydew coats leaves and stems.

Oak lecanium scale (Parthenolecanium quercifex) is a common pest on oaks.

Signs

• Reddish-brown round scales on twigs
• Honeydew on leaves
• Dark sooty mold growth

Symptoms

• Stunted plant growth
• Small flowers
• Yellowing leaves
• Early leaf drop

The female lays eggs in April and May. Crawlers (immature scale insects) hatch from eggs and crawl to new foliage to feed.

Prevention & Treatment

Cultural Controls

• Scrape scales off small trees with a light infestation
• Remove and destroy infested branches

Biological Control

• Natural enemies, including ladybird beetles (ladybugs) and parasitic wasps, often keep scales under control

Chemical Control

For heavy infestations:

• Spray with 2% horticultural oil in the spring and fall to manage adults, crawlers, and eggs
• Thoroughly coat trunk and branches

The waxy coating of adult scales protects them from chemical insecticides.

Crawlers (mobile immatures) are susceptible to conventional insecticides. Monitor crawler emergence using sticky cards, double-sided tape on branches, or bagging infested shoots or leaves and watching for crawler movement.

Insecticides labeled for use by homeowners against scale crawlers include:

• Cyfluthrin
• Permethrin
• Bifenthrin
• Cyhalothrin
• Malathion

Apply when crawlers appear and repeat in 10 days. Read and follow all label instructions and precautions.

See Table 1 for examples of specific products.

Note: Scale insect control using pesticides on larger trees is not always practical due to tree size, the need for specialized equipment, and the high associated costs.

Insecticides & Fungicides to Control Oak Insect Pests & Diseases (Table 1)

The following active ingredients are labeled for the management of specific oak diseases and insect pests. Selection depends on the target pest, tree size, and timing of application.

Product names are provided as examples only. Always read and follow all label directions. Availability and labeling may change.

Insecticides for Oak Insect Pests

Active Ingredient	Examples of Brand Names & Products
Acephate	BioAdvanced Science-Based Solutions 2-in-1 Systemic Rose & Flower Care Granules with 6-9-6 Fertilizer Bonide Systemic Insect Control II
Bacillus thuringiensis (Bt)	Bonide Thuricide Bacillus thuringiensis (Bt) Garden Safe Brand Bt Worm & Caterpillar Killer Monterey Bt Natural Guard by Fertilome Caterpillar Killer Spray with Bt Natural Guard by Fertilome Caterpillar Killer Spray with Bt Ready to Use Safer Brand Caterpillar Killer For Trees, Shrubs, & Vegetables Concentrate II Southern Ag Thuricide Bt Caterpillar Control Ferti-lome Dipel Dust Biological Insecticide SA-50 Southern Ag Dipel Dust
Bifenthrin	Hi-Yield Bug Blaster Bifenthrin 2.4 Ready to Spray Hi-Yield Bug Blaster II Bifenthrin 2.4 Ready to Spray Monterey Mite & Insect Control Monterey Mosquito Control Martin’s FLEE Ready to Use Yard Spray Ortho Outdoor Insect Killer Concentrate Ortho Bug B Gon Insect Killer for Lawns & Gardens1 Ortho BugClear Insect Killer for Lawns & Landscapes Bifen I/T Talstar P Professional Insecticide Up-Star Gold Insecticide Hi-Yield Vegetable & Ornamental Insect Control Granules Bonide Eight Insect Control Flower & Vegetable Above & Below Soil Insect Granules
Cyfluthrin	BioAdvanced Science-Based Solutions 24 Hour Lawn Insect Killer Ready-to-Spray BioAdvanced Science-Based Solutions Complete Brand Insect Killer for Soil & Turf Ready-to-Spray I BioAdvanced Science-Based Solutions Insect Killer for Lawns Ready-to-Spray BioAdvanced Science-Based Solutions Rose & Flower Insect Killer Ready-to-Use
Cyhalothrin	Bonide Eight Insect Control Garden & Home II Ready to Use Cutter Backyard Bug Control Spray Concentrate Cyzmic CS Controlled Release Insecticide Martin’s Cyonara Lawn & Garden Insect Control Martin’s Cyonara Lawn & Garden Insect Control Ready-to-Spray Spectracide Triazicide Insect Killer for Lawns & Landscapes
Horticultural Oil	Bonide All Seasons Horticulture Spray Oil Ready-to-Use Bonide All Seasons Horticulture & Dormant Spray Oil Ready-to-Spray Ferti-lome Horticultural Oil Spray Monterey Horticultural Oil Concentrate Monterey Horticultural Oil RTU Safer Brand Horticultural & Dormant Spray Oil Concentrate Southern Ag Parafine Horticultural Oil Summit Year-Round Spray Oil
Malathion	Bonide Malathion 50% Insect Control Gordon’s Malathion 50% Spray Hi-Yield 55% Malathion Insect Spray Martin’s Malathion 57% Ortho Max Malathion Insect Spray Concentrate Southern Ag Malathion 50% EC Spectracide Malathion Insect Spray Concentrate Tiger Brand 50% Malathion
Permethrin	Bonide Eight Insect Control Vegetable, Fruit, & Flower Concentrate Bonide Eight Yard & Garden Ready to Spray Hi-Yield 38 Plus Turf, Termite & Ornamental Insect Control Hi-Yield Lawn Garden Pet & Farm Insect Control Southern Ag Permetrol Lawn & Garden Insecticide Tiger Brand Super 10 Brand
Spinosad	Bonide Captain Jack’s Deadbug Brew Concentrate Bonide Captain Jack’s Deadbug Brew Ready to Spray Bonide Captain Jack’s Deadbug Brew Ready to Use Bonide Colorado Potato Beetle Beater Concentrate Conserve SC Turf & Ornamental Monterey Garden Insect Spray Monterey Garden Insect Spray RTU Natural Guard by ferti-lome Spinosad Bagworm, Tent Caterpillar & Chewing Insect Control Natural Guard by ferti-lome Spinosad Soap Ortho Insect Killer Tree & Shrub Concentrate Southern Ag Conserve Naturalyte Insect Control
RTS = Ready-to-Spray (hose-end applicator) RTU = Ready-to-Use (pre-mixed product)

Fungicides for Oak Diseases

Active Ingredient	Examples of Brand Names & Products
Chlorothalonil	Bonide Fung-onil Multi-purpose Fungicide Concentrate Bonide Fung-onil Multi-purpose Fungicide Ready to Use Ferti-lome Broad Spectrum Landscape & Garden Fungicide GardenTech Daconil Fungicide Concentrate GardenTech Daconil Fungicide Ready-to-Use Hi-Yield Vegetable, Flower, Fruit And Ornamental Fungicide Ortho MAX Garden Disease Control Concentrate Southern Ag Liquid Ornamental and Vegetable Flowable Fungicide Tiger Brand Daconil
Copper-based Fungicides	Bonide Captain Jack’s Liquid Copper Fungicide Bonide Copper Fungicide Spray or Dust Ready to Use Camelot O Fungicide/ Bactericide Monterey Copper Fungicide Garden Spray Liqui-Cop Natural Guard by ferti-lome Copper Soap Fungicide Concentrate Natural Guard by ferti-lome Copper Soap Fungicide Ready to Use Southern Ag Liquid Copper Fungicide
Horticultural Oil	Bonide All Seasons Horticulture Spray Oil Ready-to-Use Bonide All Seasons Horticulture & Dormant Spray Oil Ready-to-Spray Ferti-lome Horticultural Oil Spray Monterey Horticultural Oil Concentrate Monterey Horticultural Oil RTU Safer Brand Horticultural & Dormant Spray Oil Concentrate Southern Ag Parafine Horticultural Oil Summit Year-Round Spray Oil
Mancozeb	Bonide Mancozeb Flowable with Zinc Concentrate Southern Ag Dithane M-45
Myclobutanil	Ferti-lome F-Stop Lawn & Garden Fungicide Monterey Fungi-Max Spectracide Immunox Multi-Purpose Fungicide Spray Concentrate For Gardens
Propiconazole	Banner Maxx II Fungicide Bonide Infuse Systemic Disease Control Bonide Infuse Systemic Disease Control Lawn & Landscape Ready to Spray Ferti-lome Liquid Systemic Fungicide II Quali-Pro Propiconazole 14.3 Fungicide
Thiophanate-methyl	Southern Ag Thiomyl Systemic Fungicide
RTS = Ready-to-Spray (hose-end applicator) RTU = Ready-to-Use (pre-mixed product)

Maintaining tree vigor is the most effective strategy for preventing oak diseases and insect problems. Early identification and proper cultural care reduce the need for chemical intervention.

References

• Common Disease Pests of Oak in North Carolina, North Carolina State Cooperative Extension
• Key to Diseases of Oaks in the Landscape, University of Georgia
• Common Insect Pests of Oak in North Carolina, North Carolina State Cooperative Extension

Pesticides are updated annually. The last updates were made on 2/26 by N. Jordan Franklin.

Originally published 09/00