Articles
Echinacea Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Echinacea diseases.
Updated:
November 15, 2023
Disease | Symptoms | Pathogen/Cause | Management |
---|---|---|---|
Alternaria leaf spot | Small dark brown to black leaf spots become oblong and develop lighter-colored centers as they enlarge. Spots on young plants are often along the midrib. | Alternaria | Water in a manner that keeps moisture off the leaves and stems. Apply a fungicide to protect plants. |
Aster yellows | Flowers remain green. Leaf-like structures form in place of some flower parts and tight clusters of such flowers may form. In the spring, foliage may be bright yellow. | Aster yellows phytoplasma spread by leafhoppers | Remove infected plants. Remove weeds in the area and other aster-related plants that have similar symptoms. |
Bacterial leaf spot | Dark brown to black spots form on leaves and are angular in shape because they are limited by large leaf veins. The spots often have a yellow halo | Pseudomonas cichorii | Water in a manner that keeps moisture off the leaves and stems. Apply bactericide to protect healthy plants |
Botrytis leaf spot and stem rot | Brown spotting on leaves is sometimes accompanied by a stem rot. | Botrytis cinerea | Water in a manner that keeps moisture off the leaves and stems. Apply a fungicide to protect plants. |
Cercospora leaf spot | Brown spots form on the leaves. Tiny black dots are seen within the spots. | Cercospora tabacina | Water in a manner that keeps moisture off the leaves and stems. Apply a fungicide to protect plants. |
Foliar nematode | Purplish, angular spots form between veins. The spots become tan with age. | Aphelenchoides | Most other perennials are also susceptible to foliar nematode. Examine all surrounding plants for similar symptoms. Remove infected plants. Water in a manner that keeps moisture off the leaves and stems. |
Leaf mottle | Light and dark green blotches develop on leaves. Sometimes there dark green ring spots present or line patterns and etches formed by dead tissue. | Impatiens necrotic spot virus (INSV), cucumber mosaic virus (CMV), and others | Remove infected plants. Control thrips (that move INSV) and aphids (that move CMV). |
Sclerotinia and Sclerotium crown rot | Plants with dark spots on lower stems and dark roots wilt and die. White fungus with dark granule-like (Sclerotinia) or tan balls (Sclerotium) structures form on the surface of the dead areas. | Sclerotinia sclerotiorumand Sclerotium rolfsii | Remove infected plants. |
Septoria leaf spot | Purplish-brown spots develop on the leaves, often completely covering older leaves. | Septoria lepachydis | Water in a manner that keeps moisture off the leaves and stems. |
White smut | Yellow spots form on the leaves and become brown with age. | Entyloma compositarum | Several plants in the aster family are susceptible and should be examined for symptoms. Apply a fungicide to protect plants. |
Prepared by Gary W. Moorman, Plant Pathology Professor emeritus