- Leaves have a white or gray powder on the leaf underside. Curling is fairly uniform across a variety. Differences exist between varieties.
- Curling seems to be caused by the failure of leaf tips to expand properly. Leaf tips are often brown, black or necrotic.
- Leaves are curled, stunted and deformed when they emerge from the crown in spring. Leaf tips are green.
- Both mature and young leaves are curling upwards. Stems and petioles may also be twisted.