Cucumber leaves turn yellow due to watering issues, diseases, or pests. Preventable causes include over/under-watering, while surprises can arise from diseases and pests.
Cucumbers are heavy feeders, requiring a wide range of nutrients for proper growth.
If your plants lack any of the nutrients, it leads to chlorosis, reducing the normal green coloring in leaves.
Cucumber diseases are another problem that gardeners need to understand. There are a few diseases that cause streaks or yellow spots on cucumber leaves.
Cucumber plants are prone to a variety of pests. Pests love cucumber plants.Some pests suck the sap out of the leaves, causing leaf discoloration and yellowing.
Take a look at your plants regularly and inspect them for any signs of pests, diseases, or nutrient deficiencies. Make sure the plants get enough sunlight and avoid over and under watering them.