Cuke leaves

Question

It had nice leaves. Three days later, it’s shriveling up and dying.

Answer 1

Sudden shriveling of leaves can be a sign of bacterial wilt:
https://www.gardeningknowhow.com/edible/vegetables/cucumber/bacterial-wilt-cucumbers.htm

Here are some other possible causes:
http://www.extension.umn.edu/garden/diagnose/plant/vegetable/cucumber/leaveswilting.html

Or, a pest might have cut or damaged the stem near the soil. Check the base of the stem.