Cucumber Seedlings Turning Yellow? Follow these Tips!

Cucumber Seedlings Turning Yellow

Cucumber is a common vegetable that we can see almost throughout the year. Cucumber comes in different types and colors. This vegetable flourishes even in the summer. However, it is not free from various diseases. Cucumber leaves turning yellow is a common problem, and it can be because of various reasons.

Why Are My Cucumber Seedlings Turning Yellow?

In plants, the decrease of green color can happen with the loss of chlorophyll. Chlorophyll is responsible for giving the plant a green color, and it converts sunlight to energy. The loss of chlorophyll can turn the color of cucumber seedlings from green to yellow.

Why Is My Seedling Turning Yellow?

The seedlings of the plants can turn from green to yellow. This process can happen due to several factors. The deficiency of soil nutrition, lack of sunlight, water problems, diseases, and pest problems can turn green plants into yellow. So, you need to identify the root cause first.    

How Do You Fix Yellow Seedlings?

  • Make sure that the soil you use contains the right minerals to help the healthy growth of the plants.
  • Don’t overwater, and regularly supply the required water.
  • Provide sufficient sunlight. If you are growing cucumbers indoors, ensure to give a light source to keep them healthy.
  • Don’t apply fertilizer during the early stages of the plant. If you want to do it, apply in very few quantities.
  • Inspect whether the fungus is attacked the seedlings. If yes, apply the pesticides.
  • Take preventive measures to keep pests away.

What Does An Overwatered Cucumber Plant Look Like?

If you give more water to the cucumber seedlings, it will also affect their growth. The common problem you can see in the overwatered cucumber plant is the yellow color leaves, rotten roots, and powdery mildew. If you find all these things in a cucumber plant, it is because of overwatering.

What Are The Reasons For Cucumber Leaves To Turn Yellow Colour?

  • Water Problem

If you give more water to cucumber seedlings than it needs, it will cause problems. Cucumber plants need just about 1 to 2 inches of water every week; overwater will make it difficult for the roots to get oxygen.

  • Sunlight problem

Cucumber plants need more nutrients than other vegetable plants. If it cannot get nitrogen and potassium as per the requirements, it will start to show yellow leaves.

  • Soil problem

Like all other plants, cucumber plants also need enough sunlight to grow, but if you see any yellow leaves, it could be because of a lack of sunlight. Hence, ensure to plant in a place where it can get at least six hours of sunlight in a day.

  • Pest Problem

For leaves’ yellow color, pests can be one of the primary reasons. Whiteflies, Aphids, spider mites, and potato leafhoppers are the common garden pests that can change the color of cucumber leaves. You can use natural homemade insecticide to avoid these types of pests from your garden.

  • Diseases

The plant diseases such as fusarium wilt, cucumber mosaic virus, and downy mildew can make the color of cucumber leaves yellow. In such cases, you can cut off the yellow leaves to prevent the diseases from spreading to healthy leaves.

Should I Cut Off Yellow Cucumber Leaves?

Before cutting the yellow leaves from the cucumber plant, you need to identify the root cause of the yellow leaves. If it is because of other than a disease, you can restore the natural color. You should cut off the leaves if it is because of any disease. It will avoid the spreading of disease.

Can You Overwater A Cucumber Plant?

Overwatering any plant is not an ideal thing. The same applies to the cucumber plants. If you overwater, the roots of the plants are unable to get the oxygen, and hence it can stop the growth rate. And if you overwater, the roots will rot, and the leaves will start to lose the green and turn yellow.

How Do I  Identify Diseased Cucumber Seedlings?

  • Alternaria Leaf Blight – Irregular brown spots on leaves with yellow edges.
  • Anthracnose – Water-soaked, yellow circular spots on leaves.
  •  Bacterial Leaf Spots – Small brownish circular spots on the leaves(sometimes with yellow edges)
  • Bacterial Wilt – Yellow wilting leaves with dryness.
  •  Cucumber Mosaic – White, green or yellow lines on leaves and cucumber.
  • Downy Mildew – Light green and yellow spots.
  • Fusarium Wilt – Leaves turning yellow and brown suddenly.
  • Powdery Mildew – white powdery spots on the leaves.

What Type Of Soil Deficiency Causes Yellow Seedlings?

  • Iron Deficiency

If your cucumber leaves turn yellow but contain green veins and older leaves stay green, it is a clear indication of iron deficiency. You can spray iron liquid on cucumber plants.

  • Nitrogen Deficiency

The absence of nitrogen content in the soil is one of the major deficiencies, and it can turn the color of leaves yellow. You can overcome this deficiency by supplying nitrogen fertilizer.

  • Potassium deficiency

Cucumber plants need more potassium than nitrogen. If the plant lack potassium, its leaves will turn yellow. If you use a balanced fertilizer, it can solve your problem.

  • Zinc deficiency

If the older leaves of the cucumber turn yellow and the small leaves’ growth becomes less day by day, it indicates zinc.

What Plants Should I Avoid Planting With Cucumber Seedlings?

You should not plant potatoes and melons near the cucumber plants. You should not plant sage seedlings near the cucumber with these two plants. These plants will not allow cucumber plants to flourish. Instead of these planets, you can plant other plants that help cucumbers grow healthily.

Why My Cucumber Is Yellow?

If a cucumber turns yellow, that means it is overripe. Hence it would help if you did not leave it to turn completely yellow. Once the cucumber is overripe, the chlorophyll starts to fade and results in yellow pigments. It is not because of any deficiency. You need to pluck the cucumber before it turns yellow.


Can You Make Yellow Seedlings Green Again?

Yes. One can restore the greenness in the cucumber seedlings. But to that, it is important to identify the things that are causing the depletion of chlorophyll. Once the root cause is identified, it is easy to take appropriate action and restore chlorophyll.

What Are Good Companion Plants For Cucumbers?

There are several good companions of cucumber plants. You can plant beans, corn, peas, lentils, beets, carrots, onions, and radishes with cucumber. These plants are helpful to the cucumber plants since they supply more nitrogen to the soil and consequently make it available for cucumber plants.

How Do We Identify Sunlight Deficiency In Cucumber Seedlings?

Cucumber plants thrive in the full sunlight. It is native to South Asia, and the sunlight requirement is high. Not getting enough sunlight will result in poor plant growth and small fruits and leaves. The lack of sunlight can also result in yellow and dropping leaves.

Is It Common For Cucumber Seedlings To Turn Yellow?

Yes. Many times cucumber seedlings turn yellow. The factors that reduce chlorophyll content are more. However, it is not common to get all plants with yellow leaves. And if you do not take any action if the leaves turn yellow, it will result in the death of plants.


Cucumber leaves turning yellow is a common problem but ignoring this symptom will harm the plants severely. There are several reasons why these phenomena can happen. But thankfully, there are options for preventive and corrective measures to restore the green color. Identifying the cause early will help you to prevent the depletion of chlorophyll.

Owen Jung

Owen is the co-founder of Our Daily Homestead. Own grew up in his parent's homestead in Illinois and learned all things gardening, sustainability, and off-grid living while he was young. He now shares his knowledge through this website.

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