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Send horticultural questions to ktilt@acesag.auburn.edu.
| PLANT | DISEASE | DESCRIPTION | CONTROL |
| ARBOR-VITAE | Phomopsis Dieback | Tip browning and dieback. | Sanitation. See APMH. |
| BUDDLEA | Phyllosticta Leaf Spot | Numerous small brown circular spots. | Sanitation; Cleary's 3336 or Domain. |
| CRABAPPLE | Cedar-Apple rust (Gymnosporangium) | Large (3-6mm diam.) bright yellow spots; sometimes tiny black specks can be seen on upper leaf surface; sometimes orange spores bodies can be seen on lower leaf surface spots. | See APMH for protective spray treatments; collect and destroy all fallen leaves this fall; remove nearby red cedars and other junipers if possible. |
| CRAPEMYRTLE | Powdery Mildew (Erysiphe) | Leaves show white dusting; yellowing; new growth distorted | See the APMH. |
| DAISY, GERBERA | Powdery Mildew (Erysiphe) | Leaves show a white dusting; yellowing followed by browning. | See APMH. |
| DOGWOOD | Anthracnose (Discula) | Small-large irregular brown spots/blotches often with purple margins. Dieback usually follows | See APMH. |
| DOGWOOD | Phytophthora Root Rot | Roots become brown and water-soaked. With slight pressure, the outer cortex of the root will slip away from the central root core. | See the APMH. |
| DOGWOOD | Powdery Mildew (Microsphaera) | White dusting on upper leaf surfaces. | Cleary's 3336 or Domain. |
| DOGWOD | Spot Anthracnose (Elsinoe) | White dusting on upper leaf surfaces. | See the APMH. |
| GERANIUM | Alternaria Leaf Spot | Black, small, angular leaf spots. | See the APMH. |
| GERANIUM | Botrytis Blight | Blossoms and leaves develop brown blotches | Strict sanitation. Bordeaux mixture protective sprays. |
| GERANIUM | Pythium Stem Rot | Dark Brown, water-soaked lesions (cankers) develop on stems. | Sanitation. |
| HAWTHORNE | Entomosporium Leaf Spot | Black spots develop on the foliage. Spot coalescence may occur. | See the APMH. |
| HOLLY | Phytophthora Root Rot | Roots are black or brown and water-soaked. | See the APMH. |
| HYDRANGEA | Colletotrichum Petal Blight | Orange-brown circular spots, blotches. | Cleary's 3336 or Domain. |
| HYDRANGEA | Phytophthora Crown Rot | Roots develop a wet brown decay that becomes dried with age. | Sanitation. See APMH. |
| IMPATIENS | Impatiens Necrotic Spot Virus | Black circular spotting occurs on the foliage. New growth becomes stunted. | Control thrips; sanitation. |
| IMPATIENS | Phythium Root Rot | Roots become soft, brown and water-soaked. | See the APMH. |
| IVY, ENGLISH | Anthracnose (Colletotrichum) | Brown circular/irregular spots on the foliage. Spot coalescence may occur. | See the APMH. |
| IVY, ENGLISH | Bacterial Leaf Spot(Xanthomonas) | Black, angular, water-soaked spots on foliage. | See the APMH. |
| IVY, ENGLISH | Rhizoctonia Leaf & Stem Rot | Brown, dry lesions on leaves/stems. | Sanitation; Cleary's protective sprays. |
| JUNIPER | Cercospora Blight | Inner sections of branches turn brown and needles drop. | Benlate protective sprays. Sanitation. |
| JUNIPER | Phomopsis Blight | Branches dieback beginning at twig tips. | Sanitation; see the APMH. |
| JUNIPER | Phytophthora Root Rot | Roots become browned, water-soaked. | See the APMH. |
| MAPLE | Anthracnose (Kabatiella) | Brown circular/irregular spots/blotches occur on leaves; large leaf areas may be involved. Defoliation may result. | Sanitation. See the APMH. |
| MAPLE | Phyllosticta Leaf Spot | Circular (sometimes) irregular leaf spots. Leaf spot borders are often distinctive. Severe spotting will result in defoliation. | Sanitation. See the APMH. |
| MONDO GRASS | Anthracnose Colletotrichum) | Brown spots/blotches develop on leaves, often at/near leaf tips. | Sanitation. Cleary's or Domain protective sprays on a benomyl product labelled for ornamentals. |
| OAK | Algal Leaf Spot((Cephaleuros)) | Red-green circular spots. | Sanitation. |
| OAK | Anthracnose (Apiognomonia) | Brown, irregular-shaped and sized spots/blotches on leaves. Often, blotches will follow along leaf veins. Early leaf drop will occur when disease is severe. | Sanitation of leaves in the fall. See APMH. |
| OAK | Oak Leaf Blister (Taphrina) | Brown, puckered spots (1/8-1/2 inch diameter) develop. Spots may merge. Leaf drop will occur when disease in severe. | Sanitation. See APMH. |
| OAK | Xylella Scorch | Oaks develop drown leaf edges; dieback. | Tree removal. |
| PETUNIA | Phytophthora Foliage Blight/Root Rot | Brown, sometimes wet-looking lesions; dieback. | Sanitation; See APMH. |
| PINE | Lophodermium Needle Cast(Ploioderma) | Needles turn brown and drop; very small (1-2 mm or 1/32 inch) football shaped, black fruiting bodies. | Protective fungicide sprays during the spring and fall. |
| PRIVET | Cercospora Leaf Spot | Medium brown circular spots. | See APMH. |
| RHODODENDRON | Phytophthora Root Rot | Roots become brown and water-soaked. | See APMH. |
| ROSE | Black Spot (Diplocarpon) | Black spots with fringed borders develop on leaves. Defoliation will result from severe spotting. | Sanitation. See the APMH. |
| ROSE | Mosaic Virus | Yellow line patterns, mosaics. | Plant removal. |
| ROSE | Powdery Mildew | White dusiting on leaf surfaces; new growth distortion. | See APMH. |
| ROSE | Rhizoctonia Crown Rot | Brown lesions at soil line. | Sanitation; Cleary's protective drenches. |
| SALVIA | Phytophthora Root Rot | Roots brown, water-soaked. | Sanitation. See the APMH. |
| SNAPDRAGON | Phytophthora parasitica Crown Rot | Crowns become water-soaked, brown, rotted. | Sanitation. Avoid excessive irrigation. See APMH. |
| SYCAMORE | Powdery Mildew (Microsphaera) | White coating develops on leaves; new leaves are deformed. | Sanitation of leaves in the fall. |
| SYCAMORE | Xylella Scorch Disease | Leaf edges become browned; dieback. | Tree removal. |
| VERBENA | Powdery Mildew | White dusty coating on leaves; leaves yellow and later turn brown. | A benomyl product labelled for ornamentals or Cleary's 3336 or Domain. |
| VINCA, Catharanthus (Periwinkle) | Anthracnose (Colletotrichum) | Brown cankers on lower stems. | See APMH. |
| VINCA, Catharanthus (Periwinkle) | Fusarium Crown Rot | Brown, dry rotting on stem at soil line. | Rotation or solarization. |
| VINCA, Catharanthus (Periwinkle) | Phomopsis Stem Blight | A brown canker develops on stems. | Sanitation. Apply protective sprays of Cleary's 3336. See the APMH. |
| VINCA, Catharanthus (Periwinkle) | Phytophthora Foliage Blight | Dark brown lesions on stems and leaves; dieback. | Sanitation. Avoid wet situations. See APMH. |
| VINCA, Catharanthus (Periwinkle) | Pythium/Phytophthora Crown/Root Rot | Roots become brown, water-soaked. | Sanitation. Avoid wet situations. See the APMH. |
| VINCA, Catharanthus (Periwinkle) | Rhizoctonia Aerial Blight | Leaves become dull green and then brown. Large areas of leaves become browned. | See APMH. |
| VINCA MINOR | Anthracnose (Colletotrichum | Leaves become dull green and then brown. Large areas of leaves become browned. | See APMH under perennial vinca. |
| YAUPON, Dwarf | Phytophthora Root Rot | Roots become brown, water-soaked. | See APMH. |
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Send horticultural questions to ktilt@acesag.auburn.edu.