Pink pustules or spore masses may be seen in these cankers during moist periods. 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.