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Why Are My Cucumbers Turning Yellow? This Is Why!

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Cucumbers are loved for their fresh, cool taste and myriad of health benefits. Dehydrated? Have a cucumber or two. Trying to lose weight? Cucumber sticks with dip. Vitamin deficient? Cucumber Smoothie. Canker sores? Cucumber juice. Leaves great fresh breathe too!

why are my cucumbers turning yellow and dying

I always get excited come harvest time for my cucumbers! Imagine my surprise then– and sadness – as I readied myself to pick my first batch and found them yellow! Gone are the bright and deep greens that characterized the last batch of cucumbers I got and in its place is was pale blotchy yellow and orange.

After a thorough inspection and a depressingly large amount of research as I cradled my yellow cucumbers, I found out they were sick with the cucumber mosaic virus.

Apparently, it is spread by aphids. Sadly, I had to completely trash the ill cucumber plants while hoping it hasn’t spread to the others. It didn’t, thankfully.

When I did go through the internet for answers, I realized I wasn’t alone with this predicament. I decided to do an article on the causes for yellowing cucumbers, so you and I will never have to suffer uprooting a really good plant!

Hopefully, you’re reading this to prevent your cucumbers from turning yellow. But if they already are, let me tell you why it may have happened and what you can do!

Why Are My Cucumbers Turning Yellow

why are my cucumbers turning yellow on the vine

I’ve found that there are several factors that can cause yellowing in cucumbers. I’ve also listed the steps you can take when they do.


The most common cause and the easiest to remedy is when the cucumbers have been left too long on the vine and have become overripe. If left longer, they will eventually turn orange.

Besides their color, you can identify overripe cucumbers if they develop depressions, wrinkling or puffiness and have become swollen.

  • Once the cucumber has turned completely yellow or orange, it is no longer suitable for consumption.

If your cucumbers, depending on their variety, are of the right size and have turned yellow with a bitter taste then the most likely cause is over ripening.​

Why Are My Cucumbers Turning Yellow

Why it happens?

Cucumbers are green because of the chlorophyll present in them. The same pigments found in all green plant life. Once the cucumber reaches peak ripeness (when it’s bright or deep green) its chlorophyll levels start decreasing leaving a yellow and orange hue.

Steps to take / Points to remember

  • Cucumbers typically ripen in about 50-70 days after planting.
  • Harvest before any signs of yellowing
  • Ripe cucumbers are bright or deep green and firm to the touch.
  • ​Pick cucumbers every couple of days during the time of peak harvest.
  • ​Cucumber fruit ripen at different times so pick only those that are ready.
  • ​The ideal time for picking is in the cool early morning.
  • In addition to yellowing and bitterness, picking cucumbers too late will result in lower plant yield in the future.


Another cause of yellowing cucumbers is the Cucumber Mosaic Virus (CMV). If you notice wrinkled/withered leaves with blotches of white on your cucumber plant and fruit that varies between pale white to yellow in color with a mushy texture, then it may be infected with this disease.

  • It’s also possible for the disease to infect specific stems so some of the leaves or fruit from healthy stems may grow normally.

I learned that my blotchy cucumbers were infected with this disease. I didn’t bother keeping the seemingly healthy fruit, in fear of risking the rest of the healthy plants.

why are my cucumbers turning yellow before they get big

Why it happens?

The disease is transferred by aphids, from an infected plant to a healthy one. The aphid acts only as a temporary carrier and is not affected by the virus. Fortunately, the virus does not persist in soil or plant debris, and it cannot be passed through seeds.

Steps to take / Points to remember

  • Prevention is the best option as a cure for CMV is yet to be discovered
  • Purchasing a type of pest control to minimize aphid population
    • Here’s a really good pest control solution: Insect Killing Soap
    • If you’re wary of pest control solutions, an interesting and pretty alternative is live lady bugs. The bane of aphids, scale, mealybugs and other pets. Purchase it here.
  • If infection has occurred, I highly recommend that you immediately remove and trash all infected plants to avoid the spread of the disease.
Why Are My Cucumbers Turning Yellow

Nitrogen Deficiency

A nutrient imbalance, most importantly nitrogen, can also cause discolored and disfigured cucumbers. A lack of nitrogen causes leaves to lose the intensity of their green color and impairs the development and growth of the plant.

If your cucumber seems stunted with pale green / almost yellow leaves, exhibits misshapen, blotchy and yellowed fruit, it may lack proper nitrogen supply.

Why Are My Cucumbers Turning Yellow

​Why it happens?

Like most plants, cucumbers need large amounts of nitrogen as much as it needs sunlight. In fact, nitrogen is vital in the production of chlorophyll, which fuels the plant’s conversion of sunlight into energy.

Therefore, a nitrogen deficiency means less food for the plant hindering both plant growth and fruit yield.

Steps to take / Points to remember​

  • If left untreated, the yellow hue will spread through the entire plant, and future yield is reduced. Plant will eventually weaken and die.
  • ​Note that discolored leaves are also caused by other nutrient imbalances such as deficiencies in calcium, magnesium, and manganese
  • Consider a plant fertilizer like this.

Sunlight deprivation

Another possible, but uncommon, cause of yellowing (yellow spots, specifically) is found with ripened cucumbers that have been left lying on bare soil due to a low-lying stem.

Why Are My Cucumbers Turning Yellow

Why it happens​?

The yellow spots, usually on the side in contact with the soil, are caused by a deprivation of sunlight. The lack of natural light hinders the plants from producing sufficient chlorophyll.​

Steps to take / Points to remember​

  • Plant the cucumber in a location that will give it a lot of sunlight.
  • Remedy low lying fruit that is in contact with soil by using a trellis.
    • A good example of a trellis.
    • In addition to cleaner fruit, using a trellis also minimizes disease and rot

Yellow cucumber variety

Amusingly, yellowed cucumbers aren’t always bad. There are varieties of cucumbers that are yellow such as the lemon cucumber. It was named so because of its lemon-like size and lemon-like color – yellow!

Two more yellow-colored cucumber varieties are the Chinese yellow cucumber and the Indian yellow cucumber!

Many have been surprised to find large yellow cucumber fruit coming from their supposedly green cucumber plants.​

Why it happens​?

It seems that seeds of different varieties can get mixed up! Who knew?

Steps to take / Points to remember

  • If it wasn’t obvious enough, make sure you’re purchasing the seeds for the right cucumber variety!


Back on that serious note, I have here a very informative video about growing healthy cucumbers:

You’re now fully equipped from keeping your cucumbers from turning yellow! Share this article (or a cucumber salad) and help your friends save their tasty cucumbers!


sheila oxley

Sunday 26th of August 2018

I'm hoping you can answer this...My cucumbers turned yellow after I picked them. I thought it might have been because I didn't refrigerate them right away and left them on the counter, but another article I read online said that cucumbers don't continue to ripen after being picked. Thanks in advance for any help!