My Cucumber Leaves Are Turning Yellow

Cucumbers are included among some of the most-loved vegetables out there. Packed with nutrients and excellent water content, there are few vegetables that compare with the benefits of cucumber. Naturally, many of us want to grow this healthy and adorable plant in our own gardens to be able to reap our own fresh and juicy cucumbers.

Like all other plants, cucumbers require a lot of love and care. So after everything you do, if you notice one day that the leaves of your cucumber plant are turning yellow, you will be mad! It would feel like a personal failure in so many ways.

Fortunately, once you figure out why the leaves of your cucumber plant are turning yellow, you can provide corrective measures as well to help restore the plant to its original vitality and lush green-ness. Here are some of the most common reasons why your cucumber plant might be turning yellow:

Scientific Cause of Cucumber leaves Turning Yellow:

All plants get their green coloration from a chemical known as chlorophyll. When leaves begin to discolor by turning yellow or any other color, they begin to lose the chlorophyll that is naturally contained in their leaves. The process of losing chlorophyll is known as chlorosis, and there could be a myriad of reasons why chlorosis could overtake your beautiful plants and make them lose color.


Yes, cucumbers are known for being the vegetables with the highest water content of all vegetables. Most other types of products cannot compare with the level of hydration a cucumber can provide. And it is also true that cucumbers need a lot of water to be able to grow healthily.

However, there is no denying the fact that even plants with a high-water content like cucumbers also run the risk of being overwatered. Overwatering refers to adding too much water to a plant which can make the roots of the plant rot, make the plant moldy and susceptible to pest attacks, and even make the plant prone to a lot of other conditions. And yes, one of the most common effects that overwatering can have on a cucumber plant is that it could make the leaves turn yellow.

Cucumber plants need around 1-2 inches of water every week, and more than that could damage the roots of the plant, make the plant rot or turn the leaves of the plant yellow. If you think you have been watering the plant more than that, it might be time to change that routine.

First, you need to determine if your plant is actually overwatered or not. For that, you can either use moisture sticks or simply place your hand on top of the soil to determine how wet the soil is. If you have not watered it the same day, but the soil is still wet, you might have a classic case of overwatering on your hands.

To reverse the effects of overwatering, you need to do two things. First, you need to ensure that the damage to the roots is minimal. If your plant is small, you should carefully remove it from the roots and determine the damage. If you see any roots that have become soft or soggy, or if you have any signs of mold, remove those parts of the roots carefully. Place the plant back into the soil with only healthy roots.

Secondly, you should ensure that your plant is getting enough drainage. Make sure there is enough room for the water to be drained from the soil. You can do this by using a pot with holes for drainage or porous soil as well.

Nutrient Deficiency

Another major reason for the leaves of a plant turning yellow is nutritional deficiencies. Plants get their nutrition from the soil and the fertilizer and compost you use in the soil. If a cucumber plant is not receiving enough potassium or nitrogen through the soil it is planted in; there is a high chance that the leaves of the plant will turn yellow.

If you think nutritional deficiencies are the cause for this, you might be faced with a soil issue. This means that there might be other plants in your garden that are also yellowing or showing other deformities. If the issue is widespread and not just limited to your cucumber plant, the culprit is likely nutritional deficiencies.

In case it is a nitrogen deficiency, you can do a number of things to restore the soil to its original vitality. For example, coffee grounds are packed with nitrogen that is easily absorbed by the soil. Other than that, you can even invest in nitrogen-rich fertilizer and add it to the soil.

You can make an excellent potassium-rich concoction for your soil with the help of some banana peels as well. Simply soak a few banana peels in water for 24-48 hours. After that, simply remove the banana peels from the water and use them to water your cucumber plant and any other plant which is going through a similar conundrum.

If you are regular in adding fertilizer to your plants, you will be much less likely to see nutritional deficiencies and their symptoms in any of your plants.

Lighting Concerns

Cucumber plants are bright green and packed with chlorophyll, which needs a hefty amount of sunlight to be activated. So if the leaves of your cucumber plant are yellowing, there is a chance that your plant just isn’t getting enough sun. You can easily gauge this if you know the state of the weather in your area and how much direct sunlight your cucumber plant receives. If your cucumber plant is kept under slight shade or is only getting indirect light, it might be a reason why its leaves are turning yellow.

In this case, you will want to move your plant to a more well-lit area. If the shade of another plant or some other object is obstructing the light for your cucumber plant, you might want to consider removing that as well. Make sure your cucumber plant is getting at least six hours of direct sunlight every day. If the lighting was truly the cause for yellow leaves, you would notice the leaves turning back to a lush green in no time!


Pests love cucumber plants and can easily attack them if not cared for aptly. The most commonly found pests on a cucumber plant include potato leafhoppers, spider mites, aphids, and white flies. These insects feed off of the sap found in the cucumber leaves. When the sap slowly leeches out of the leaf, it can begin to turn yellow in color.

The biggest reason why you should get rid of pests on your cucumber plant as soon as you see them is that these pests can eventually kill your plant by consuming all of the plant’s nutrients. The potato leafhopper is an exceptionally dangerous pest to cucumber plants since it injects its saliva inside the plant, which causes it to turn yellow and makes the leaves slowly fall off. The good thing is that if your plant is indeed under attack by pests, you will be able to see it easily since the pests are very much visible.

Of course, the easiest solution to getting rid of pests on your plant is by using insecticide. There are many options for insecticides available on the market, and they will all be useful in getting rid of the bugs that are turning your cucumber leaves yellow. But many insecticides you see on the market are very harsh and can actually damage your plant further instead of letting it heal. So, for this reason, you should try to pick a gentle insecticide. Only use the harsh ones if the attack is very extensive.

Conversely, you can also make your own insecticide at home that will not be quite as awful to your cucumber plant as an industrial-grade insecticide. Make your own insecticide by mixing water, dish soap, and rubbing alcohol in a spray bottle. Spray the leaves of the plant and any other infected parts every day till you see a significant reduction in the pests. Once all the insects are away from the plant, you will notice that the leaves of the cucumber plant will begin to regain color slowly.

Once the pests are gone, you should take extra care that another such attack does not affect the cucumber leaves in your garden again by taking preventative measures.

Firstly, you need to ensure that the plant in question is healthy. It receives ample nutrients, the soil receives enough fertilizer, and the plant is also adequately watered. Pests often do not attack plants that are healthy. However, pests can cross-contaminate your healthy cucumber plant if it is surrounded by weeds or other plants that are harboring pests. Pests from neighboring plants can attack your cucumber plants and turn their leaves yellow as well. If you think this is the case, you should remove the cucumber plant from that area and thoroughly get rid of the pests from the infected plant before reintroducing your healthy plant back into that place.

Letting pests linger on your plants for a long time will eventually kill the plant or make it very difficult to recover.


Cucumber plants can also be subjected to a variety of diseases that can turn their leaves yellow and make the plant look unsightly.

One of these diseases is the cucumber mosaic virus. Cucumber plants attacked by this disease show mottling, flecking, and patterns that resemble a mosaic as well. The disease is spread by aphids and can affect multiple plants in the same area very quickly.

To heal your plant, you will have to remove it from the soil it is planted in and move it to a disease-free area. You should then adequately sterilize and treat the soil to get rid of the pest since it can live in the soil for years.

Another common disease affecting cucumber plants is downy mildew. This refers to a disease that attacks the plant in wet and humid areas. In this disease as well, you can see a yellowing, spotty appearance on the leaves of the plant. Since this disease is essentially a fungal infection, you can use plant fungicides to get rid of it. If you spot the disease early, applying fungicides to the affected leaves is the most effective treatment.

You can also carefully remove any parts of the plant that show visible signs of infection as well.

If left untreated, downy mildew can affect the entire plant slowly, turning the leaves from yellow to brown and allowing the plant to die as well eventually.

The last disease that can affect cucumber plants is fusarium wilt. This is also a fungal infection that can persist for a long time in the soil of the plant. This disease affects the vascularity of the plant, and if left untreated, the infection can easily kill the plant. Many plants that are affected by Fusarium wilt begin to turn yellow and slowly die off as well.

If you believe that your cucumber plant has contracted fusarium wilt, you need to remove the entire plant from the soil to prevent the infection from being contracted by any other plants in the soil as well.

There is no real cure for a fusarium wilt infection, and most plants that contract this infection must be removed from the soil.


Cucumbers are some of the best plants to grow in your garden since you will have an infinite supply of pickles, and they also make a delicious snack. However, the leaves of these plants often turn yellow, and it is usually a sign that something is not right. You can make use of our helpful tips to gauge exactly what the problem could be and then slowly help to recover the plant from the situation. While yellowing leaves are usually a cause of concern, the problems are usually easily rectified.