If your cucumber plants are turning yellow, it is a sign that they need more sunlight. Cucumbers require at least six hours of direct sunlight on a daily basis to harvest their best. If you live in an area with short growing seasons, you may need to move your cucumbers inside a greenhouse or use artificial light sources to ensure that they get enough sunlight.

Why is my cucumber plant turning yellow of cucumber plant yellowing is insufficient water. Cucumbers need a minimum of one to two inches of water each week. Using an irrigation system can help you keep your watering consistent, but if the weather is hot and dry, you may need to water more often.

When you do water, be sure to only water the soil and not the leaves. Wet leaves are a breeding ground for fungus, and the hot sun can scorch them easily. Additionally, splashing a lot of water on the cucumber leaves can lead to rot and stunt the growth of your plants.

ellowing Pepper Leaves: Causes and Cures for a Bountiful Harvest

Cucumber plants need a variety of nutrients, including nitrogen, phosphorus, and potassium to foster growth. A deficiency in any of these nutrients can cause yellow leaves and reduce fruit production. You can test your soil for nutrient deficiencies using a home testing kit, and amend the soil with compost or an all-purpose vegetable fertilizer to restore the balance.

A lack of chlorophyll, a green pigment that enables plants to grab and harness sunlight to produce energy, can also lead to yellow leaves. This condition is known as chlorosis, and it can be a death knell for your cucumber plants if not addressed.