Strawberries: Expanded leaves (only) are crinkled, and crack underneath when pulled

Frost damage

Frost causes the newly expanding leaves to crack underneath when gently pulled. Leaves have a slightly darker color than normal. Blossoms may also be affected by late frosts. More strawberry frost damage information

Two strawberry runners on white background. Runner on left is healthy and turgid. Runner on right appears wilted and has darker olive color throughout.
Upper leaf surface of healthy Albion runner (on right) and frost damaged Albion runner (on left). 
Back side of two strawberry runners on white background. Runner on left is healthy with pale green leaf undersides. Right runner is crumpled and has olive green leaf undersides with a noticeable decrease in overall turgor.
Leaf undersides of healthy runner (on left) and frost damaged runner (on right).