No chemical control is listed. Downy mildew causes problems on iberis. No chemical control is listed. Powdery mildew causes a white or gray growth on the leaves. Spray with sulfur or benomyl to control this disease.
White rust causes blisters on any part of the plant except the roots.
Yellowed areas form on the upper leaf surfaces with white pustules on the undersides. Remove infected parts as seen. No chemical control is listed. This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.