common cucumber diseases

The technique and process to grow cucumber plants are quite simple, but you need to pay attention to some signs of common cucumber diseases to ensure healthy growth, high quality, and productivity. In this article, you will learn several experiences to define, prevent and treat diseases in cucumbers.

1. Powdery Mildew

powdery mildew cucumber
Photo shows some cucumber leafs with white powdery mildew.

It’s supposed a common disease in cucumber plants. You easily see the sign of this disease. White powdery substance surrounds and spreads the leaves. At first, a few small spots appear on leaves. Then, they disperse throughout the leaves.

The serious infection will make the fruit grow slowly and affect quality. The infected leaves will wilt and fall off before they grow completely. Please notice that watering too much and bad air circulation worsens the disease.

The treatment for the first stage of the powdery mildew is fungicidal sprays. However, it can make leaves wet. To prevent this, you must apply an underground or surface watering method. Sprinkling neem oil can stop spots from expanding. Don’t sprinkle when the weather is hot. Ensure that plants are under efficient sunlight to hamper the infection.

2. Bacterial Wilt

bacterial wilt cucumber

A cucumber plant infected bacterial wilt will wither away and die soon. To check if a plant has this disease, you can rub white substances by fingers to see if they stick your palm skin.

As its name, this disease is from a kind of bacteria. It infects vascular tissues, so the plants get fast wilt. Bacterial wilt organisms will create sticky substances to stick to tissues; therefore, water cannot move to parts of the plant.

The disease appears in a single leaf at first.  It will spread the whole of the plant. To stop the infection, you must remove infected plants. You also should apply pesticides to put the disease under control and make sure it won’t happen later.

3. Cucumber Beetles

Cucumber Beetles

You can realize a cucumber beetle with its black and yellow stripes. Some cucumber beetles are spotted. They bite and make small holes in flowers or leaves. They transmit wilt disease and like to suck young plants while their larvae eat roots.

You can catch cucumber beetles by hand. They move slowly in the morning and evening. Insecticide is one of the methods. You will choose and spray insecticide. Notice that you need to end the insecticide method when young plants blossom.

4. Cucumber Mosaic

Cucumber Mosaic
Cucumber Green Mottle Mosaic Virus (CGMMV).

Cucumber mosaic is one of the common cucumber diseases. It influences the flower, leaf, and stem. It hampers the growth of the plant. If the disease breaks out, several problems will happen. The yellow mosaic shows up on leaves. Cucumber plants lose nutrients. Size of leaf decreases. Leaves become curly then fall off fast.

You can see weird changes in flowers which are disease signs. Aphids pass this disease to plants. They carry the virus and infect plants.

To prevent cucumber mosaic, it’s important to keep beetles and aphids away from your area. Grow the good-quality seed and remove weeds. Apply pesticide and mineral oil to kill insects.

Read more: Cucumber Plants Dying From Bottom Up – How To Revitalize Your Garden

5. Alternaria Leaf Blight

This disease is from a fungus. The fungus exists in polluted water or soil. The wind also can carry the fungus to cucumber plants. The disease develops easily in wet and warm weather.

The mature leaves are attacked. Small brown spots appear on leaves at first. The spots can turn into different shapes. Next, the leaves wilt and fall down.

You should notice some details in the treatment. The main effective treatment is fungicides.

  •  As fungicides may make the fruits inedible, you have to pay attention to instruction, time to spray and more.
  • A homemade fungicide is a good idea. You mix soapy water, baking soda, and vinegar together.
  • In case, just a few parts of the plant are infected, you must eradicate them to avoid the spreading. When the plants are seriously infected, you need to eliminate them, improve or replace the soil, then begin the harvest again.

6. Downy Mildew

 Downy Mildew cucumber
A downy mildew disease on cucumber’s leaves.

You can guess a cucumber plant that is infected by downy mildew. Angular yellow spots appear on leaves. You can use many methods to fight against downy mildew.

It’s necessary to check your garden often. When you find out a plant infected, you must remove it immediately to avoid expanding. Spray fungicides to eradicate the disease.

Check out this video to learn a cure for diseases in cucumber plants.


It’s essential to prevent and wipe out common cucumber diseases. Give plants the best conditions to grow healthily and avoid diseases. Find out signs of diseases as soon as possible to stop them from the first stage.



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