Cucumber Plant Leaves Drying Up. To prevent an outbreak, spray with organic liquid copper as soon as rain is forecast, and every 10 days until dry conditions return. Drying leaves on (lemon) cucumber plants.
Infected leaves grow dull and often wilt in the heat of the day. I have been growing cucumbers under 40% shade net. Leafminers make small tunnels in the leaves of plants.
A second possible reason for squash and cucumber leaves drying up and shriveling is nematodes, but i have found most healthy plants to be largely resistant to nematodes.
The plant is still producing blossoms and fruit. Trick picking the beetles off by hand and use an organic pesticide to keep them from coming back. Look for holes in the leaves and disfiguration on the fruits. A second possible reason for squash and cucumber leaves drying up and shriveling is nematodes, but i have found most healthy plants to be largely resistant to nematodes.