Hydrangea: Failure to bloom categories: Hydrangea Hydrangea Diseases Ornamentals Shrubs revision date: 2022-12-02 12:00 Biology Improper pruning is the most common reason hydrangeas fail to bloom. Both bigleaf (Hydrangea macrophylla) and oakleaf (H. quercifolia) hydrangeas produce their flowers on the previous year’s growth. If these stems are removed, new growth may fail to produce flowers […]
Hydrangea: Fungal leaf spots categories: Hydrangea Hydrangea Diseases Ornamentals Shrubs revision date: 2022-12-02 12:00 Mycosphaerella leaf spot, www.forestryimages.orgPhoto by: B.J. Jacobsen, NCSU Biology Several fungal diseases cause spotting of leaves on hydrangeas. Symptoms may include brown, black, or gray spots or angular blotches. These may be surrounded by a reddish or purple halo. Spotting may […]
Hydrangea: Hail damage categories: Hydrangea Hydrangea Diseases Ornamentals Shrubs revision date: 2022-12-02 12:00 Hail damage to hydrangea leafPhoto by: J. Glass Biology Damage to plants depends on size of the hailstones and intensity of the storm. Minor damage may not show immediately, but may appear days or weeks later as small whitish scars or spots […]
Hydrangea: Herbicide damage categories: Hydrangea Hydrangea Diseases Ornamentals Shrubs revision date: 2022-12-02 12:00 Biology Symptoms of herbicide damage may be confused with damage from insects, disease, or cultural problems. Specific injury symptoms vary depending on degree of exposure, product used, and plant species. Damage may not appear immediately, and plants may exhibit symptoms for more […]
Hydrangea: Leaf scorch categories: Hydrangea Hydrangea Diseases Ornamentals Shrubs revision date: 2022-12-02 12:00 Leaf scorch on hydrangeaPhoto by: J. Glass Biology Leaf scorch on hydrangea is a common physiological problem. Typical symptoms include yellowing leaves, or irregular dry, brown blotches. Leaf tips and margins may turn brown, as well. Severely damaged leaves may drop from […]
Hydrangea: Marginal leaf necrosis categories: Hydrangea Hydrangea Diseases Ornamentals Shrubs revision date: 2022-12-02 12:00 drought damage to H. macrophyllaPhoto by: R. Maleike Biology Browning and dieback of leaf margins and tips can be a symptom of several problems that restrict water flow to the leaves. Drought, excess heat, excess sunlight, overfertilization, and herbicide injury are […]
Hydrangea: Powdery mildew categories: Hydrangea Hydrangea Diseases Ornamentals Shrubs revision date: 2022-12-02 12:00 Powdery mildew on hydrangeaPhoto by: Dept. of Plant Pathology, NCSU Biology Powdery mildew is a fungal disease affecting leaves, young shoots, and flowers. White to grayish, powdery fungal growth develops on the top of the leaf and may also appear on tender […]