What diseases and pests affect irises?
Irises are hardy, easy-to-grow perennials with few problems. In the Spring you may see some fungal leaf spot (during rainy, moist conditions) which can be treated with a fungicide. Bacterial soft rot has a rotten potato smell and can quickly kill the iris. Rot is caused by excessive water when the soil is warm or hot. Removing the dead tissue and applying a chlorine cleanser like Comet may save the plant. Common pests like aphids can usually be controlled by lady bugs, applying a solution of soapy water, or using a pesticide.
