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NC State Extension

BOLO July

Month-by-month lists of common plant diseases, pests, and other problems you may encounter in North Carolina yards and gardens.

Back to BOLO list of months.

Turfgrasses

Brown patch (fescue/ryegrass)

Fairy ring (all turfgrasses)

Gray leaf spot (fescue/St. Augustinegrass)

Pythium blight (fescue/Kentucky bluegrass/ryegrass)

Summer Patch (Kentucky bluegrass/fine fescue)

Chinch bugs (St. Augustinegrass)

Woody Ornamentals

General: Slime mold on mulch in landscape beds

Multiple hosts: Phytophthora root rot, Armillaria root rot, Botryosphaeria dieback, powdery mildew, sooty mold, improper planting, herbicide injury, heat/drought stress, decline from cold injury last winter, overfertilization

Multiple shrub species: root-knot nematodes

Arborvitae: Phytophthora root rot, Armillaria root rot

Azalea: Phytophthora root rot, Armillaria root rot, Phomopsis dieback, stunt nematode,  Azalea prominent caterpillars (Datana major; young/small)

Black cherry: black knot

Boxwood: Phytophthora root rot, boxwood blight, boxwood stem canker (Colletotrichum theobromicola), nematodes (lesion, root-knot, spiral)

Camellia: Glomerella canker, Phytophthora root rot

Cherry, flowering: shothole (Passalora) and leaf blight (Blumeriella)

Cherry-laurel: shot-hole, Botryosphaeria canker/dieback

Crabapple: powdery mildew, cedar-apple rust

Dogwood, flowering: powdery mildew, scorch (heat/drought), Septoria leaf spot

Elm: Dutch elm disease on American and winged elms, black spot

English Ivy: anthracnose, bacterial leaf spot, Phytophthora root rot

Euonymus: powdery mildew

Gardenia: root-knot nematode, Phytophthora root rot

Hydrangea: Cercospora leaf spot

Indian hawthorn: Entomosporium leaf spot

Japanese black pine: pine wilt nematode

Japanese holly: black root rot, Armillaria root rot, Botryosphaeria canker/dieback

Junipers: Phytophthora root rot (except Eastern red cedar), Armillaria root rot, Annosum root rot, Phomopsis tip blight

Leucothoë: powdery mildew – note red spots on top of infected leaves

Leyland cypress: Phytophthora root rot, Armillaria root rot, Cypress (Seiridium) canker, Botryosphaeria canker/dieback, algae on foliage, internal browning

Loropetalum: bacterial gall (knot)

Magnolia, Southern: algal leaf spot

Maple: anthracnose, Phyllosticta leaf spot

Oaks: oak leaf blister (Taphrina) turning brown, bacterial leaf scorch, anthracnose (Discula, Apiognomonia), Tubakia leaf spot, slime flux (mainly on oak but can occur on maple, elm, hickory, and some other hardwoods), branch pruning by squirrels

Pear, flowering: fire blight, quince rust

Pine, white: ozone injury

Redbud: Cercospora (Passalora) leaf spot, bacterial leaf scorch

Red-tip photinia: Entomosporium leaf spot

Rhododendron: Botryosphaeria canker/dieback

Rose: Armillaria root rot, common canker, crown gall, black spot, rose rosette

Spiraea: powdery mildew

Spruce: Stigmina needle blight, Rhizosphaera needle cast 

Sycamore: scorch from heat/drought, bacterial leaf scorch, anthracnose

Tulip (yellow) poplar: premature fall color due to drought

Herbaceous Ornamentals (Perennials, Bedding Plants)

Multiple hosts: Southern stem blight (Sclerotium rolfsii), Rhizoctonia root/stem/crown rot, root-knot nematodes, overfertilization, nutrient deficiencies

Begonia: Pythium root rot, root-knot nematode

Coral bells (Heuchera): Phytophthora root/crown rot

Coreopsis: powdery mildew

Daylily: leaf streak

Impatiens: Rhizoctonia crown/stem blight, downy mildew*, Pythium root rot, root-knot nematode
*New Guinea impatiens are not susceptible to downy mildew

Iris: Heterosporium (Cladosporium) leaf spot, bacterial soft rot

Ironweed: Powdery mildew

Liriope: anthracnose on leaf tips, Fusarium crown rot, Phytophthora root, and crown rot

Monarda: powdery mildew

Peony: leaf blotch (measles), ring spot (Tobacco rattle virus)

Petunia: Phytophthora crown/stem rot, Rhizoctonia stem rot

Rudbeckia: Septoria leaf spot, downy mildew, aster yellows

Vinca, annual (Catharanthus): Phytophthora root rot and aerial blight, Rhizoctonia aerial blight

Zinnia: powdery mildew, Alternaria leaf spot, bacterial leaf spot

Fruits & Nuts

Multiple hosts: herbicide injury, too much or too little fertilizer, drought stress

Apple: cedar-apple rust, black rot, and frogeye leaf spot, bitter rot, sooty blotch, and flyspeck

Blackberry: cane blight, virus diseases

Blueberry: Botryosphaeria stem blight, Phytophthora root rot

Cherry and plum: black knot

Grape, bunch: downy mildew, anthracnose, black rot (fruit), Pierce’s disease, herbicide injury

Grape, muscadine: black rot (leaves), Pierce’s disease, herbicide injury

Peach: scab, brown rot (fruit phase), plum curculio

Pear: Fabraea leaf spot

Pecan: anthracnose, scab

Vegetables & Herbs

Multiple hosts: herbicide injury, root-knot nematodes, Pythium root rot, Southern stem blight (Sclerotium rolfsii), overfertilization, nutrient deficiencies, poor fruit set due to high temperatures

Basil: downy mildew

Beans: anthracnose (leaves, stems, pods), Cercospora leaf spot, Rhizoctonia root/stem rot

Cucurbits: downy mildew, powdery mildew (esp. squash, pumpkin), anthracnose, Fusarium wilt, gummy stem blight (esp. watermelon), Choanephora fruit rot, aphid-borne viruses, root-knot nematode, ozone injury (esp. watermelon)

Pepper: bacterial spot, blossom-end rot

Thyme: Rhizoctonia aerial blight

Sweet corn: corn smut (Ustilago maydis)

Tomato: blossom-end rot, bacterial wilt, bacterial spot, Septoria leaf spot, Fusarium wilt (esp. heirloom varieties), early blight, late blight, Southern stem blight (Sclerotium rolfsii), gray leaf spot, Pythium root rot/damping off, Tomato spotted wilt virus (leaf and fruit symptoms), root-knot nematode, Magnesium deficiency, physiological leaf roll, growth cracks

Arthropods of the General Landscape

Cicada killers (males guarding territories, females nesting)

Wheel bugs (adults)

Southeastern subterranean termite swarmers (Reticulitermes virginicus)

Green June beetles (Cotinis nitida; may attack ripe fruit)

Two-lined spittlebug (adults; often on hollies)

Arthropods Associated with Multiple Plants

Planthopper nymphs (Flatidae & Acanaloniidae)

Fall webworms

Japanese beetle (particularly roses and grapes)

Bagworms (Thyridopteryx ephemeraeformis; older larvae present)