Plant in well drained soil and avoid excessive nitrogen fertilization. When dieback occurs, prune out and destroy diseased twigs. Preventive sprays with a foliar fungicide are effective. The first evidence of infection is the appearance of small, brown irregular-shaped spots on the petals. Spots are white on colored flowers and brown on white flowers.
Affected petals have a veined appearance and remain firm.
Flowers may have a freckled appearance. The flower collapses and sticks to the foliage. Where flower blight has previously occurred, spray soil and litter around plants with a recommended fungicide four weeks before bloom. Spray at regular intervals during the blooming period. Fungicidal sprays at 7-10 day intervals during periods of high humidity will prevent serious foliage damage.