SOME COMMON DISEASES OFTEN SEEN IN SEPTEMBER
| PLANT | DISEASE | DESCRIPTION | CONTROL |
| AUCUBA | Lasiodiplodia Canker | Black sunken spots or sunken areas on aucuba stems. Dieback of foliage results. | Cleary's 3336, or Domain protective sprays labelled for ornamentals; sanitation. |
| AZALEA | Cercospora Leaf Spot | Small dark brown-black, usually circular spots (1-2 mm) scattered over leaf surface. | Sanitation and Cleary's 3336 protective sprays. |
| AZALEA | Phytophthora Crown and Root Rot | Lower stem near soil and roots become brown and water-soaked. | Sanitation and proper soil or potting mix drainage are important. See APMH and/or ANR-571. |
| AZALEA | Rhizoctonia Aerial Blight | Brown, irregular spots and lesions begin on lower leaves. Whole leaves may become blighted; leaf drop occurs. | Sanitation; See APMH. |
| BEGONIA | Phytophthora Crown Rot | Crown tissues are dark and wet-rotted. | Sanitation. Reduce watering. |
| BEGONIA | Phytophthora & Pythium RootRot | Roots become brown and water-soaked, decayed. | Sanitation. Reduce watering. See the APMH. |
| BEGONIA | Rhizoctonia Root Rot | Brown, dry, decayed roots. | Sanitation. Banrot protective drenches. |
| BEGONIA | Root-Knot Nematode (Meloidogyne) | Galls on roots; plants stunted and wilted. | Solarization. |
| BEGONIA | Tomato Spotted Wilt Virus | Yellow mosaic and ring spots present. Sometimes brown spots also present. | Thrips control. Sanitation. |
| BOXWOOD | Phytophthora Root Rot | Brown, water-soaked roots. | See APMH. |
| CELOSIA | Phytophthora, Pythium, Fusarium Lower Stem Rot & Root Rot | Roots brown and decayed. | Sanitation. Reduce watering. Improve soil drainage. |
| CHERRY | Septoria Leaf Spot | Small (0.5 cm or less in diam.), angular brown spots. | Sanitation in the fall. |
| CLEYERA | Phytophthora Root Rot | See Boxwood. | Sanitation. Improve soil drainage. |
| CYPRESS, LEYLAND | Cercospora (Cercosporella) Blight | Needle and twig blight that usually begins on lower foliage. | Sanitation. Cleary's 3336 protective sprays. |
| DOGWOOD | Botryosphaeria Canker | Slightly sunken lesion, sometimes with cracks along the margin. | Sanitation. |
| DOGWOOD | Cercospora Leaf Spot | Angular-irregular tan-brown lesions (2-6 mm diam.) sometimes with a thin yellow halo. | Usually sanitation is the only control measure needed. |
| DOGWOOD | Septoria Leaf Spot | Angular, brown spots, about 1 cm or less in diam; may be confused with Cercospora leaf spot. | Collect and remove fallen leaves this fall. |
| DUSTY MILLER | Alternaria Leaf Spot | Dark, angular spots. | Sanitation; Cleary's 3336. |
| ELEAGNUS | Phytophthora Root Rot | Brown, wet root decay. | Sanitation. Improve soil drainage. |
| EUONYMUS | Anthracnose (Colletotrichum) | Small brown spots (about 5 mm or smaller) on foliage. | Sanitation; See the APMH for protective fungicide recommendations. |
| FERN | Anthracnose (Colletotrichum) | Gray-brown irregular blotches on fronds. Orange spore masses may be present in humid weather. | Sanitation; See the APMH under leaf spot. |
| FERN | Rhizoctonia Aerial Blight | Gray or brown irregular blotches on fronds; some 'shot-hole'. | Sanitation; See the APMH. |
| GARDENIA | Phytophthora Crown Rot | Lower stem/trunk at the soil line develops wet decay. | Sanitation. (See the APMH under Root Rot for protective treatment.) |
| HICKORY | Scab (Cladosporium) | Small, dark brown, slightly raised leaf spots. | Sanitation in the fall. |
| HOLLY, BLUE MAID | Botryosphaeria Canker | Brown or black sunken, cracked lesions (cankers) on branches. | Sanitation. Protective sprays of Cleary's 3336, Domain or a WP benomyl labelled for ornamentals. |
| HOLLY, BLUE MAID | Phytophthora Root Rot | Feeder roots become water-soaked, decayed. | See the APMH. |
| HYDRANGEA | Cercospora Leaf Spot | Relatively large (0.5-1.0 cm) dark brown circular spots with reddish borders. | Sanitation. See the APMH. |
| HYDRANGEA | Phytophthora & Pythium Root Rot | Roots become brown and water-soaked. | Sanitation. See the APMH. |
| IMPATIENS | Alternaria Leaf Spot | Small circular or angular dark brown spots. | Sanitation; a mancozeb product such as Duosan or Zyban. |
| IRIS | Bacterial Soft Rot | Soft, wet, watery rot of rhizome. | Sanitation. Control insect problems. |
| IRIS | Fusarium Rhizome Rot | Areas of the rhizome exhibit a dry, brown rot. | Sanitation. See the APMH. |
| IVY, ENGLISH | Phytophthora Crown & Root Rot | Tissues dark and water-soaked. | Sanitation; reduce irrigation or improve drainage. |
| JUNIPER | Phomopsis Dieback | Juniper branch tips become brown. Cankers develop on twigs and dieback continues down the twig. | See the APMH. |
| JUNIPER | Phytophthora Root Rot | See Holly. | . |
| LIGUSTRUM | Cercospora Leaf Spot | Brown irregular spots (about 1 cm diam.) on foliage; when leaf spot is severe, defoliation may result. | Sanitation; See the APMH. |
| LIRIOPE | Anthracnose (Colletotrichum) | Brown irregular blotches on leaf blades; often, leaf tip areas are involved. | Sanitation; See the APMH. |
| LORIPETALUM | Pythium Root Rot | Light brown, water-soaked, rotted roots. | Sanitation. Reduce irrigation or improve soil drainage. |
| MAPLE | Anthracnose (Kabatiella) | Brown spots and blotches on foliage; enlarged spots may involve more than half of individual leaves. | Sanitation. See the APMH. |
| MAPLE | Phyllosticta Leaf Spot | Gray circular spots (¼ inch diam., approx.) with dark brown or reddish brown borders. | Sanitation. |
| MARIGOLD | Alternaria Leaf Spot | Small (0.2-0.3 cm diam.) dark brown-black spots. Numerous spots cause death of plants. | Sanitation. See the APMH. |
| OAK | Powdery Mildew (Microsphaera) | White dusty coating on upper leaf surfaces. Some distortion of new leaves. | Collect and remove fallen leaves this fall. |
| OAK, PIN | Xylella Scorch | Lower and oldest leaves show leaf edge scorch; problem progresses upward through the tree canopy. Dieback develops; eventual tree death. | Remove dying trees. |
| PANSY | Anthracnose (Colletotrichum) | Small, round, light brown, cream-colored spots. | Sanitation. Cleary's 3336. |
| PANSY | Myrothecium Crown Rot | Dieback; decayed crowns. | Sanitation; See A. Hagan. |
| PANSY | Phytophthora & Pythium Root Rot | Brown, wet-rotted roots. | Sanitation. See APMH. |
| PANSY | Phyllosticta Leaf Spot | Relatively small (2-3 mm diam.) medium brown, roughly circular spots. Spot centers may become gray. | Sanitation. Protective sprays of Cleary's 3336, Domain, or a benomyl WP labelled for ornamentals. |
| PANSY | Phytophthora Root Rot | Roots become brown and water-soaked. | Sanitation. See the APMH. |
| PANSY | Pythium Root Rot | Roots become brown and water-soaked. | Sanitation; See the APMH. |
| PANSY | Thielaviopsis Root Rot | Roots become covered with black spots/ lesions. | Sanitation; Cleary's, or Domain protective drenches. |
| PEAR, BRADFORD | Fabraea Leaf Spot | Black circular spots (about 0.2-0.4 cm diam.) | Sanitation of fallen leaves in the fall. Regular spray schedule may help. |
| PETUNIA | Phytophthora Root Rot | Roots water-soaked, decayed. | Sanitation |
| PHOTINIA | Armillaria Root Rot | Plant may decline slowly or suddenly; lower trunk under the bark and roots may be covered with closely appressed white fungal mat with black, threadlike structures. | Sanitation. See PP-145. |
| PHOTINIA | Phytophthora Root Rot | See Azalea. | . |
| 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 brown needles. | Protective fungicides spray. See APMH. |
| PINE, VIRGINIA | Rhizosphaeria Needle Cast | Needles become gray-brown. Twig blight may develop. | Sanitation. See the APMH. |
| PITTOSPORUM | Southern Blight (Sclerotium rolfsii) | Lower trunk becomes rotted and softened. White mycelial mats and tiny black spherical bodies (sclerotia) may be present on trunk at soil surface. | Sanitation. |
| POINSETTIA | Rhizoctonia Stem Rot & Root Rot | Lower stems develops dry medium-dark brown surface lesions; roots may become brown and dried. | See APMH. |
| POINSETTIA | Pythium Root Rot | Roots become medium brown, soft, water-soaked and rotted. | See APMH. |
| 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. |
| POINSETTIA | Bacterial (Erwinia) Stem Rot | Black, water-soaked spots or lesions on stems. Lesions may girdle stems. | Sanitation; pot-level irrigation; See APMH. |
| RED CEDAR | Phomopsis Tip Blight | Tips of twigs become yellowed and browned. Dieback may spread down the twig-branch. Lower foliage is affected first. | Sanitation. See the APMH. |
| ROSE | Phytophthora Root Rot | Dieback; active infections are wet-rotted; old infections are dried. | Sanitation; reduce watering. |
| SCHIP LAUREL | Bacterial Leaf Spot (Xanthomonas) | Angular brown spots with water-soaked margins; shot-holes develop. | Sanitation. |
| SNAPDRAGON | Cercospora Leaf Spot | Pale brown angular leaf spots of variable size. | Cleary's 3336, Domain, or a benomyl labelled for ornamentals |
| THRIFT | Rhizoctonia Blight | Stem and leaf browning. | Sanitation; Cleary's 3336. |
| VERBENA | Anthracnose (Colletotrichum) | Circular black spots on foliage. | Sanitation; Cleary's 3336. |
| VERBENA | Pythium Lower Stem Rot | Brown water-soaked lesions. | Sanitation; reduce irrigation. |
| VINCA (Periwinkle) | Anthracnose (Colletotrichum) | Brown irregular areas, blotches develop on leaves and stems. | Sanitation. Protective sprays of Cleary's or Domain or a WP benomyl labelled on ornamentals may help. |
| VINCA (Periwinkle) | Phytophthora Stem Rot and/or Crown/Root Rot | Stems and/or lower stems near soil line and roots become browned and water-soaked. | Sanitation; improve soil drainage. |
| VINCA (Periwinkle) | Pythium Root Rot | Roots become brown decayed and water-soaked. | Sanitation. Reduce watering schedule. Rotate to different crop. |
| VINCA (Periwinkle) | Rhizoctonia Aerial Blight | Lower leaves become blighted; a thin mycelial webbing may develop. | Sanitation; Cleary's, Domain or a WP benomyl labelled on ornamentals may help. |
| WAX MYRTLE | Anthracnose (Colletotrichum) | Brown, irregular spots, blotches develop on leaves. | Sanitation; if disease is severe, protective sprays of Cleary's 3336 or Domain or a WP benomyl may help. |
| WAX MYRTLE | Gummy Stem Blight (Mycosphaerella) | Black lesions/spots at leaf edges; elongate cracking on stem with amber-colored ooze. | See APMH. |
  
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