English ivy is an evergreen vine that trails along the ground and is sometimes found climbing up trees, walls, fences and your garden trellis. Often used on rocky slopes, hillsides and under trees, English ivy has a vigorous growth habit that makes it a very effective ground cover for less-than-perfect areas. English ivy is a hardy, strong, durable plant, but it is susceptible to several damaging diseases.
Symptoms of the bacterial leaf spot include brown or black oddly-shaped spots on leaves. First noticed on older foliage, it will spread to other leaves. Spots may have a bright yellow area around them and a water-soaked edge. Younger leaves can speckle and appear deformed. Bacterial leaf spot is caused by the bacterium xanthomonas campestris pv hedera and is the most common disease of the English ivy plant.
Controlling leaf spot is difficult and requires good sanitation practices. Remove all dead and damaged foliage and burn them. Clean benches and tools with disinfectant. Reduce over-head irrigation of plants, keep plants well fertilized and use the proper mix of chemical solutions suggested for leaf spot.
Often confused with leaf spot, anthracnose begins with the same sort of circular dry brown or reddish spots that can be seen in leaf spot. Lesions may form on the petioles and stems that will cause shoots to die back and leaves will begin to fall from the ivy.
Anthracnose spreads quickly to plants that are near one another and are watered by over head sprinklers. Good sanitation practices help prevent the spread of this disease. Remove dead stems and leaves and burn them. Water plants early in the day to allow foliage time to dry before evening. Don't touch plants when they are wet. Control insects and mites and apply the proper solution of fungicide to plants.
Aerial Blight and Root Rot
Both aerial blight and root rot are diseases caused by a pathogen called rhizoctonia solani. Initial symptoms of aerial blight appear on the lower leaves of the English ivy plant. Brown, water soaked lesions are noticed on the above ground part of the plant. A red-brown fungus is often seen on blighted leaves. Root rot appears when the pathogen spreads to the root of the plant. Roots may develop brown lesions and will rot causing plants to wilt, die back and experience poor growth.
Warm, humid conditions perpetuates the development of rhizoctonia solani. Good cultural practices are best for controlling this disease. Don't reuse pots or soil when planting new ivy. Clean tools and hoses, wash benches with disinfectant and water plants by mid-day. Remove damaged leaves and stems and burn them. Proper use of fungicides can help control blight and root rot.