SOME COMMON DISEASES OFTEN SEEN IN OCTOBER
| PLANT | DISEASE | DESCRIPTION | CONTROL |
| AUCUBA | Botryosphaeria Blight | Black elongated lesions on stems cause a dieback. Also, black irregular lesions may develop on leaves. | Sanitation; Cleary's, Domain or a benomyl labelled on ornamentals may help. |
| AZALEA | Cercospora Leaf Spot | Brown circular or angular leaf spots of variable size. | See the APMH under Rhizoctonia web blight. |
| AZALEA | Colletotrichum Leaf Spot | Brown circular-irregular spots (2-3 mm) diameter. | Sanitation; usually this is a stress related problem which develops in the fall. |
| AZALEA | Phomopsis Canker | Brown, sunken, elongated stem lesions. | Pruning 3 inches beyond the canker margins. Cleary's protective sprays after pruning may help. |
| AZALEA | Phytophthora Root Rot | Brown, water-soaked root decay. | Sanitation; protective fungicide treatments. See ANR-571. |
| AZALEA Liners and Containers | Rhizoctonia Root Rot | Brown, dried dying roots. | Sanitation. See APMH. |
| AZALEA Liners and Containers | Phytophthora Root Rot | Brown, water-soaked dying roots. | Sanitation. See APMH. |
| BOXWOOD | Volutella Blight | Brown stem cankers and leaf blight; orange wet spore masses. | Sanitation; Cleary's 3336; remove stress. |
| CACTUS, Christmas | Fusarium Crown Rot | Lower trunk becomes decayed with brown dried tissues. | Sanitation. Do not save soil. |
| CALENDULA | Rust (Coleosporium) | Yellow-orange brown spots (0.3-0.8 cm diam.) with a yellow halo of 1-2 mm wide. | Removal of calendula from close proximity to black pine and Scots pine (alternate hosts) may help. |
| CEDAR | Armillaria Root Rot | Rapid or slow dieback; thin white mycelial mat under bark at soil line; thin black threads may be present under bark. | Sanitation. |
| CHRYSANTHEMUM | Alternaria Blight | Dark Brown, irregular spots on foliage. | Sanitation; see APMH. |
| CHRYSANTHEMUM | Fusarium Crown Rot | Lower stem becomes reddish brown, dried and dead; lesion may be one-sided on stem or may extend around entire stem. | Sanitation; see APMH under Fusarium wilt. |
| CHRYSANTHEMUM |
Stem Blight, Pseudomonos syringae and Erwinia carotavora. | Black, wet rotting of stem. | - |
| COLEUS |
Anthracnose (Colletotrichum) | Circular-irregular brown lesions on foliage. | Sanitation. Cleary's 3336. |
| CRAPEMYRTLE | Cercospora Leaf Spot | Brown angular leaf spots of variable size. | Sanitation and protective sprays of Cleary's 3336. |
| CYPRESS, LEYLAND |
Cercospora (Asperisporium or Cercosporidium sequoiae) Lower Limb/Needle Blight | Lower limbs browned in spots with abundant (microscopic) sporulation of C. sequoiae. | Sanitation. |
| CYPRESS | Seridium Canker | Sunken lesion on stem/branches. | Sanitation. |
| DIANTHUS | Pythium Crown Rot | Lower stem becomes dark, and water-soaked. | See the APMH. |
| DIANTHUS | Rhizoctonia Crown Rot | Lower stem becomes brown and dry rotted. | Sanitation. See the APMH. |
| DOGWOOD | Cercospora Leaf Spot | Small (3-5 mm) brown, irregular spots scatttered over leaf surfaces. | Sanitation. |
| ELM | Powdery Mildew (Phyllactinia orUncinula) | White, powdery dusting on leaves. | Sanitation of leaves in the fall. |
| EUONYMUS | Crown Gall (Agrobacterium tumefaciens) | Woody irregular gall that encircles lower stem area. | Sanitation; crop rotation. |
| FATSIA | Phytophthora and Pythium Root Rot | Roots become brown and water-soaked; the outer cortex will slip easily off the root central cylinder. | Sanitation; remove wet conditions. |
| FERN, Boston | Pythium Root Rot | Outer root cortex easily slips from inner core; plants yellow and dieback. | Sanitation; See the APMH. |
| HOLLY | Botryosphaeria Canker | Sunken, cracked lesions with brown decay under bark. | Sanitation. |
| HOLLY | Oedema | Small (1-2 mm), raised, corky, light-medium brown spots on lower leaf surfaces. | Reduce watering during cloudy weather; improve soil drainage. |
| HOLLY | Phyllosticta Leaf Spot | Small (2-4 mm diam.) irregular or circular brown leaf spot. | Sanitation; see the APMH. |
| HOLLYHOCK | Pythium Root Rot | See comments for Dianthus. | Sanitation. Improve soil drainage. |
| HOLLYHOCK | Rhizoctonia Root Rot | See comments for Dianthus. | Sanitation. Cleary's 3336 protective drenches. |
| HOSTA | Root-Knot Nematode (Meloidogyne) | Plants grow poorly. Root galls evident. | Solarization of the area before replanting. |
| HYDRANGEA | Cercospora Leaf Spot | Brown angular leaf spots of variable size. | Sanitation. See the APMH. |
| HYDRANGEA | Alternaria Leaf Spot | Brown oval leaf spots. | Sanitation. |
| IMPATIENS | Pythium Crown Rot | Lower trunk becomes brown and soft-decayed. | Sanitation; correct wet soil problem; see APMH. |
| IVY, English | Anthracnose (Colletotrichum) | Irregular brown leaf spots (3-10 mm diam.) and dark brown elliptical lesions on stems. | Sanitation; see APMH. |
| IVY, English | Phytophthora Stem, Root, and Leaf Rot | Brown, water-soaked dying stems, roots, leaf area. | Sanitation; see APMH. |
| JUNIPER | Pestalotia Blight | Sections of foliage turn brown and dead; stress related. | Sanitation; remove stress condition. |
| JUNIPER | Phomopsis Tip Blight | Tip ends of branches turn brown. Blight moves from twig tips into inner foliage. Lower foliage may be affected first; seen more in nurseries than landscapes. | Sanitation; Cleary's 3336 protective sprays. See the APMH. |
| JUNIPER | Phytophthora Root Rot | Feeder roots become brown and wet rotted. They eventually dry out. | Sanitation. Solarization before replant may help. Improve water drainage |
| JUNIPER | Seridium Canker | Sunken, brown lesion on branches. | Pruning 3-4 inches beyond the edge of canker; after pruning, protective Cleary's sprays may help. |
| LOQUAT | Anthracnose (Colletotrichum) | Brown irregular spots on leaves and stems; some large blotch areas along veins. | Removal of fallen leaves; pruning of disease stem area; Cleary's protective sprays. |
| MAPLE | Anthracnose (Colletotrichum) | Irregular, spreading, brown lesions on leaves and small twigs. Leaf lesions may occur and develop along veins. | Correct and remove all fallen leaves. Protective fungicides used only when trees are small. |
| MAPLE | Cristulariella Zonate Leaf Spot | Brown-gray zonate circular-oval leaf spots. | Sanitation in the fall. |
| MAPLE | Phyllosticta Leaf Spot | Circular brown spots with dark brown or purple margins. | Sanitation in the fall. |
| MARIGOLD | Alternaria Leaf Spot | Angular or round black spots. | Sanitation. |
| MONKEYGRASS | Anthracnose (Colletotrichum) | Brown blotches on leaves; sometimes blotches begin at leaf tips; black fruiting bodies may be visible as tiny black dots in lesions. | Sanitation; Cleary's 3336 or Domain protective sprays. |
| OAK, Pin | Xylella Scorch Disease | Dieback with leaf edge scorch. | Sanitation. |
| ORCHID, Oncidium sp. | Colletotrichum Leaf Spot | Brown irregular spots. | Sanitation; Cleary's 3336. |
| PANSY | Anthracnose (Colletotrichum) | Brown stem lesions (cankers) on lower stems. Also brown circular-irregular leaf spots of variable size. | Sanitation. See the APMH. |
| PANSY | Cercospora Leaf Spot | Leaf spots are black, circular areas of feathery patterned discoloration. | Sanitation. |
| PANSY | Myrothecium Crown Rot | Crowns brown and decaying with tiny black capped white spore masses. | Sanitation. See A. Hagan. |
| PANSY | Pythium Crown Rot and Root Rot | Light-medium brown, water-soaked crowns and roots. | Sanitation. See APMH. |
| PANSY | Phytophthora Root Rot | Roots become brown and water-soaked. | Sanitation. See the APMH. |
| PANSY | Pythium Root Rot/Crown Rot | See description for Pythium. | See Pythium. |
| PANSY | Thielaviopsis Root Rot | Black spots (lesions) on roots. | Sanitation; Cleary's 3336 protective treatment. |
| PERIWINKLE (Vinca) | Stem Canker(Colletotrichum); May be secondary | Sections of lower stems become brown and dead. | Sanitation. Cleary's 3336. |
| PERWINKLE | Pythium Root Rot | Roots become brown, soft & rotted. | Sanitation |
| PERIWINKLE | Phytophthora Aerial Blight | Sections of foliage become blighted. Stems develop brown lesions. | Sanitation |
| PERIWINKLE | Phytophthora Root Rot | Roots become brown, soft and rotted. | Sanitation. |
| PINE, Virginia | Lophodermium (Ploioderma) Needle Cast | Older needles turn brown and drop; very small (1-2 mm or 1/32 inch) football shaped, black fruiting bodies develop on browning needles. | Protective fungicides sprays in the fall and spring. See APMH. |
| POINSETTIA | Bacterial (Erwinia) Stem Rot | Black, water-soaked spots or lesions on stems. Lesions may girdle stems. | Sanitation. See the APMH. |
| POINSETTIA | Fusarium Root and Lower Stem Rot | Roots and lower stems become reddish-brown, dried and dead. | Sanitation; Banrot drenches. |
| POINSETTIA | Pythium Stem and Root Rot | Lower stems and roots become medium brown, soft, and watersoaked and rotted. | Sanitation. See the APMH. |
| POINSETTIA | Rhizoctonia Stem Rot and Root Rot | Lower stems develop dry, medium-dark brown surface lesions; roots may become brown and dried. | See the APMH. Use Cleary's 3336 or Topsin M |
| POINSETTIA | Rhizopus Stem Rot | Stem sections become glassy and water-soaked; a delicate black mass of fungal threads and small black spherical structures may develop over the lesions. | Sanitation. |
| POPLAR | Anthracnose | Brown, circular-irregular leaf spots which may follow along leaf veins. | Sanitation of fallen leaves in the fall. |
| RHODODENDRON | Cercospora Leaf Spot | Relatively large (5-15 mm diam.) irregular, brown spots. | Sanitation; use Cleary's 3336 or Topsin M or a WP benomyl (not Benlate). |
| RHODODENDRON | Phytophthora Crown Rot | Dark brown, wet decay at lower stem area. | Sanitation; see APMH. |
| RHODODENDRON | Pythium Crown Rot | Dark brown, wet decay at lower stem area. | Sanitation; see APMH. |
| ROSE | Cercospora Leaf Spot | Brown angular leaf spots of variable size. | Sanitation; see the APMH under black spot. |
| WILLOW | Cercospora Leaf Spot | Small circular, brown spots. | Sanitation of leaves in the fall. See the APMH. |
| WILLOW | Rust (Melampsora)> | Rust-colored powdery spots that later become brown-colored. | Sanitation of leaves in the fall |
  
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Send horticultural questions to ktilt@acesag.auburn.edu.