Both leaves and stems are attacked by this fungus. Leaves develop irregular tan to brown blotches, often with concentric lighter and darker zones with dark brown margins. These blotches gradually increase in size until the entire leaf turns brown or black and dies. Stem cankers appear as a browning of the stem at the terminal, mid-stem, or at ground level. As these cankers girdle the stem, they cause the whole plant to wither and die.
Plants often die in patches and the disease commonly produces circular patterns in the bed.
Volutella blight is more severe in plantings weakened by winter injury, insect infestation, recent transplanting or shearing, drought, and exposure to full sun. To manage this disease, all plant debris and severely diseased plants should be removed and destroyed. Since Volutella blight is associated with plant stress, attempts should be made to control insect infestations and to maintain good growth and vigor by watering during periods of drought and by fertilizing in the spring. The planting should be thinned periodically to prevent dense growth and increase light and air circulation. Fungicides can also supplement other control strategies.