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Why Cucumber Leaves Turn Yellow? (5 Reasons & Solutions) 

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Are you worried about your cucumber plant? Don’t know why cucumber leaves turn yellow?

The cucumber plant is one of the refreshing plants in summers full of nutrition and is grown by many homeowners in their backyard. They can grow easily with the right condition without extra care anywhere.

No matter what time of year it is, a healthy cucumber plant has dark green leaves. If you are seeing yellow leaves on your cucumber plants, that’s because they lack chlorophyll, and the process is called Chlorosis. Here, you must pay attention as there’s likely to be something wrong.

And you must know the real causes behind why cucumber leaves turn yellow? This blog post will explore the five most common reasons for cucumber leaves turning yellow – and, more importantly, how to solve the problem!

Why Cucumber Leaves Turn Yellow
Cucumber leaves turning yellow. What is causing this? – via Reddit

5 Reasons of Cucumber Leaves Turn Yellow and Their Solutions

Let’s explore each of these in more detail why cucumber leaves turn yellow.

Nutrient Deficiency

If you’re a garden, one of the main things you should take care of is that your plants are getting enough nutrients to develop properly. Lack of nitrogen, phosphorus, potassium, magnesium, or other essential nutrients can cause leaves to be yellow and even die.

One way to tell if this is the problem is to look at the veins in your cucumber leaves. If they’re still green, the plant is likely getting enough nutrition, but if the veins are yellow, likely, the plant is not getting enough of a particular nutrient.

The best way to solve this problem is to test your garden soil and then use a well-balanced fertilizer that is used for cucumber plants. You can use it in ratio 5-10-10 or follow the instructions on the package. You can also add compost to the soil to help increase these nutrients.

But here’s you must remember that do not over-fertilize your plant as it can harm your plant. Too much of anything is never good. Over-fertilization can cause a pH imbalance in the soil, affecting the health of your cucumber plants.

Watering Too Much or Too Little

Like other plants, Cucumbers need about 1-2 inches of water per week, including rainfall, but they don’t like to be overwatered. If you’re seeing yellow leaves on your cucumber plants, you may be giving them too much water. This can cause oxygen-deprived roots, and the plant can wilt.

The best way to tell if you’re watering your plants too much is to feel the soil. If it’s wet, likely, you don’t need to water them yet.

Also, make sure your cucumber plants are planted in a location where they can get good drainage – a drainage system with drip irrigation can make it easier to grow a cucumber plant. And if you see drainage issues, lose the soil with sand. 

Lack of Sunlight

The cucumber plant is a sunny spot lover! It needs six to eight hours of sunlight per day to grow properly. If they’re not getting enough sun, the leaves will start to turn yellow.

This is because the plant is not able to produce enough food for it, and it will start to die off. The best way to solve this problem is to move your cucumber plants to a location where they will get more sunlight.

Why Cucumber Leaves Turn Yellow 2
Cucumber Leaves Turn Yellow – via Reddit

Pests Diseases

One of the most common reasons why cucumber leaves turn yellow is because pests have infected the plant. Aphids, spider mites, whiteflies, and other pests can damage the leaves of the cucumber plant, causing them to turn yellow.

Cucumber plants can resist pests for a shorter period of time if the pest attack grows, infecting the plant largely, it gets succumb. Let’s learn about these common pests and how do they affect the cucumber plant:

  • Aphids: green and yellow oval-shaped tiny insects found on the underside of the leaves that leave a black sticky substance called honeydew, which infects the leaves, causing them to turn yellow.
  • Spider mites: Spider mites are tiny spiders that are found on the undersides of leaves. They spin fine silvery webs and feed on the plant’s sap. This can damage the leaves and cause them to turn yellow.
  • Whiteflies: Whiteflies are tiny white insects that leave behind honeydew, like aphids.

If you have found your cucumber plant being infected by these pests, the best way to solve the problem is to use a pesticide or insecticide, especially for cucumber plants.

Make sure you read the instructions carefully and follow them closely. You can also try using organic methods like soap spray or neem oil to get rid of unwanted bugs.

Cucumber Diseases

Cucumber plants can also be affected by diseases. Some of the most common cucumber diseases are downy mildew, cucumber mosaic virus, and Fusarium Wilt. Let’s see how they are responsible for turning cucumber leaves yellow and their treatment.

Downy Mildew

Downy mildew is a foliar disease in which the cucumber leaves have yellow leaves on the upper surface of the leaves. It causes due to highly humid conditions and cool temperatures. To treat your cucumber plant from Downy mildew, improve the air circulation, and cut the affected leaves.

Mosaic Virus

Mosaic Virus is caused by a fungus that lives in the soil and affects the leaves of cucumber plants. The symptoms of the disease are wrinkling leaves curving downwards with yellow spots. You can prevent the mosaic virus from spreading by cutting off the affected part of the plant.

Fusarium Wilt

It is the disease caused by soil fungus ‘Fusarium oxysporum f. sp cucumerinum’ that can retain for a longer duration. The symptoms of the disease are yellow leaves around the edges, and sometimes the leaves become dull, gray-green.

Also, you can observe spots that are dark brown in color at the lower part of the stem. It is suggested that remove the affected part of the plant to treat this disease.

The Take-Away

As you can see, there are a number of reasons why cucumber leaves turn yellow. But don’t worry, if you identify the problem and take action quickly, you can save your plants! Just remember to be patient and give them the care they need, and they will reward you with delicious cucumbers.

I hope this article helped you find the real cause and its solution; please let us know with your comments. If you have some unique experiences, don’t forget to share them with us.