Why my cucumber leaves turning whiteCucumber leaves turning white is not a good sight for any cucumber plant parent as this can mean an unhealthy plant. Many people find this a difficult situation to deal with. Read our expert guide below to learn how to diagnose these white spots and then treat them accordingly.

It’s easier than you think!

Why Are My Cucumber Leaves Turning White?

Your cucumber plant leaves might be turning white due to powdery mildew, pests or unsuitable environmental conditions. Find out the various causes behind this condition in detail below.

– Powdery Mildew

Powdery mildew is a very prevalent fungal infection that is often the primary reason behind cucumber plants turning white. Two fungal species are responsible for producing this infection. The symptoms of both are more or less the same.

  • How To Spot Powdery Mildew

Cucumber leaves turning white around the edges is usually the first indication that your plant is suffering from a mildew infection. This is followed by the appearance of tiny white spots on the upper surfaces of the leaves.

These white spots continue to enlarge until they merge with each other. Eventually, the entire leaf appears to be covered by a velvety or fuzzy white substance. If left untreated, these white spots will spread to the whole plant.

In some cases of mildew attacks, the white spots are also accompanied by browning and curling of the leaves.

  • Is Powdery Mildew Dangerous?

No, powdery mildew itself is not a dangerous disease. Some plants afflicted by it can survive for years, but the problem arises when the leaves become totally covered with the layer of white, fuzzy fungal hyphae.

This layer prevents the leaves from performing photosynthesis. As a result, the plant is unable to produce enough food for itself. This then leads to wilting and leaf drop. The growth of the plant is also affected, and you will notice that the fruit being produced is of a poorer quality.

– Pests and Bugs

Pests and bugs might be causing your cucumber plant to turn white. Discover which pests are usually the common culprits.

  • Leafhoppers

Some pests are quite destructive for your plants. Leafhoppers love to attack the leaves, piercing them and sucking sap from them. A prolonged leafhopper infestation will weaken the leaves of your plant and drain it of its sap.

You will notice that the leaves will start developing white spots and patches. They might then curl up and become dry and wrinkly. After some time, they might start falling off as well.

  • Thrips

Thrips are tiny, thin pests about 1.5 cm long that might be attacking your cucumber plant. Here is how you can identify a thrip infestation.

They feed on leaves and as a result, a rasping pattern starts developing on the affected leaves. Rasping refers to the appearance of a silvery-white mottled pattern on the upper surfaces of the leaves. Thrips also leave black feces as evidence of their existence. If you cannot find live thrips on your plant at a given time, try looking for their feces instead.

– Overwatering

Overwatering will also cause your leaves to turn whitish in appearance. This is because excess water drives away nutrients and causes the leaves to become swollen. They then appear white and dull.

The cucumber plant needs only one inch of water on a weekly basis. Water slowly and not more than once per week.

– Not Enough Sunlight

Your cucumber plant leaves can also turn white due to inadequate sun exposure. Not getting enough sunlight will lead to decreased amounts of chlorophyll in the leaves. This in turn will make them appear greyish or white.

– Transplant Shock

Transplant shock is an often occurring condition that takes place right after transplanting a plant. A transplant is when you transfer a plant from one potting soil to another. It is usually a temporary condition that resolves by itself.

However if you notice the leaves and cucumber stems turning white after a transplant, this could be indicative of a bigger problem. Usually, it shows that the roots or stems have sustained some sort of damage.

Sometimes a plant’s immunity drops down significantly after a transplant. This makes it more susceptible to a powdery mildew infection.

How Can I Fix White Cucumber Leaves?

Providing the correct environmental conditions, using chemical treatments or a vinegar solution can help fix white cucumber leaves and bring them back to good health.

Now you know how to identify and diagnose the reason behind your cucumber leaves turning white. The next step is how to fix this problem. We bring you the easiest solutions to the problems that might be responsible for your leaves turning white.

Jump down below to learn what they are.

– Powdery Mildew: Various Methods To Treat It

The good news is that a powdery mildew infection is never as bad as it seems at first look.

White spots on cucumber leavesUnless things have gotten really bad and your plant is experiencing rapid exfoliation, this is a very easily treatable condition.

Continue reading to find out some home and store-bought remedies for treating white spots on cucumber leaves caused by powdery mildew.

  • Home Treatments

There are some very effective home treatments for mildew infections. Their main advantage is that not only are they convenient to apply, but they are also relatively safer compared to store-bought treatments. The only downside to them is that they need to be applied consistently for a long time before your plants start showing any improvement.

Find out what these home treatments are below.

– Vinegar

One common household ingredient that you can use against mildew infection at home is good old vinegar. Mix only 3 tablespoons of vinegar in one gallon of water. Spray this mixture on your plants once a day in moderate amounts.

Using too much vinegar or spraying this mixture too often can burn your plant, so be careful with it. In a few weeks, your plant will definitely start showing improvement.

– Neem Oil

Neem oil also works wonders when it comes to treating mildew. It is easily obtainable from your local general store. You can put it directly on the white spots using a cotton roll, but take care to use only a few drops at a time.

Neem oil can also be mixed with water or milk and then sprayed on the affected plant. You will need to do this once a week for several months until the white spots on cucumber leaves disappear.

– Milk With Water

Milk with low-fat content acts as a potent natural antiseptic and antifungal agent. Mix skim milk with water in a ratio of 1:9 and then spray it on the plant. In a few weeks, you should start seeing improvements.

  • Chemical Treatments

The treatments given below are for those who don’t want to sit and wait for home DIY treatments to start working and would prefer instant results.

– Antifungal Sprays

Spraying your mildew-affected plant with a potent fungicide will get rid of the white powder on cucumber leaves caused by the fungus.

– Sodium Bicarbonate

Mix one tablespoon of baking soda with one tablespoon of common soap. Add one gallon of water to it and spray until the whole plant and its soil becomes saturated with this mixture. Your plant will heal in no time.

– Leafhopper Attacks: How To Treat It

Leafhoppers are very common pests of the cucumber plant. They are easily noticeable as green, brown or yellow-colored insects lurking underneath leaves and stem sheaths. A plant infested with these bugs will start exhibiting a whitish cast on its leaves.

They are very easy to get rid of. Simply use a water jet or a cotton roll to physically remove them from your plant. Applying oil of a thick consistency will also kill them off.

– Thrips Infestation: Removal Methods

A thrips infestation is more serious than a leafhopper one. This is because they attack flowers and fruits along with the leaves, and if their number is large enough, they can cause significant damage to the yield of your cucumber plant. Learn how to get rid of them here.

If they are small in number and visible, physically remove them from the plant. You can do this either by spraying them with a water jet or plucking them off one by one using a cotton pellet.

Gently washing your plant using soap and water has also been known to decrease the thrips population in it. Under serious conditions, you will need to resort to an insecticide. Always choose a mild one that isn’t too harsh for your plant.

– Do Not Overwater Your Plant

Contrary to popular belief, the cucumber plant doesn’t need to be watered every single day!

Change your irrigation habits in order to get rid of those white spots on cucumber leaves. To start things, water only once a week.

Always check the soil to see if it’s dry before watering the cucumber plant. You can do this by sticking a pencil or a screwdriver into the soil to see if it comes out dry or not.

Pour water on the soil near the base of the stem and avoid bathing the entire plant when watering. Making the whole plant wet will also make your plant more susceptible to fungal rot.

– Provide Adequate Sunlight

If your cucumber plant is not getting enough sunlight and has whitish leaves, then it’s time to move it to a more suitable location under the sun.

The cucumber plant needs at least eight hours of sunlight each day. It can tolerate being put under direct sunlight. In fact, it prefers staying under the full sun more than partial shade conditions.

If grown indoors, the southern-facing window is the ideal place for this plant as it receives the most intense sunlight for most of the day.


Will leaving cucumber leaves in water make them white?

No, leaving cucumber leaves in water won’t make them white. The color change may indicate a disease or environmental stress.

Are white cucumber leaves a sign of root rot?

White cucumber leaves can signify root rot, but it’s not the only cause. Checking the roots and soil can confirm the diagnosis.

Can cucumber plants survive with white leaves?

Cucumber plants with white leaves may survive, but they may not produce healthy fruits. Identifying and addressing the underlying issue is important.


Cucumber leaves turning whiteIn this article, you learned how to figure out the cause of your cucumber leaves turning white and what to do about it. Here is a brief recap of everything we have covered so far:

  • Cucumber leaves can turn white due to a number of reasons.
  • One of the main causes behind cucumber leaves turning white is a fungal infection called powdery mildew.
  • Powdery mildew causes the whole leaves to become covered by a network of white spots.
  • Natural remedies against mildew are milk with water, neem oil and diluted vinegar. You can spray the affected plant with a fungicide or sodium bicarbonate spray.
  • Cucumber leaves can also develop white spots as a result of pest attacks by leafhoppers and thrips.
  • Always try to get rid of pests physically before resorting to using insecticides.
  • Some other common reasons that might be causing your leaves to turn white are overwatering, inadequate sun exposure and transplant shock.

It’s time you stop worrying about your cucumber plant leaves turning white and start working towards solving this problem using our comprehensive guide.

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