Anthracnose (fungus – Gloeosporium spp.): Brown lesions on the leaves, in which tiny fungus fruiting bodies may be seen with a hand lens. Apply dithiocarbamate or copper fungicides.
Crown Gall (bacterial – Agrobacterium tumefaciens): Both the stems and roots may have good size galls. Destroy heavily infected plants. Plants will lack vigor and may die back. If only a few galls, prune out and destroy. Sterilize pruner with 70% alcohol or 10% household bleach.
Powdery Mildew (fungus – Oidium spp.): White powdery mold or gray “felt” patches on leaves. Leaves may yellow, curl, and drop early. Prune to thin out shrub. Use preventive fungicide sprays.
Root Knot Nematodes: (nematode Meloidogyne spp.): (See section on Root Knot Nematodes)
Other Diseases (fungi): Other fungi known to cause disease on euonymus in Texas are Phymatotrichum omnivorum (root rot), Exosporium concentricum(leaf spot), and Phyllosticta euonymi (leaf spot).