When you spend time preparing your soil and devoting your time trying to growing the perfect cucumber only to find that your cucumber plant turning yellow and therefore isn’t performing as well as you had hoped. In this guide, we will go through the most common or perhaps not so common cucumber plant diseases, causing your plants to fail. Cucumber plant problems are something that you will want to get on top of as soon as possible.

Cucumber plant diseases – Quick links:

• Alternaria leaf blight
• Anthracnose
• Fruit rot
• Aster yellows
• Squash mosaic virus
• Cottony leak
• Cabbage looper
• Flea beetles
  

Misshapen or bitter fruit

Cucumber plant problems can have your fruit turn out in a mishappen way which can be irritating and can be caused by low pollination or poor fertility.
Fruit not setting can be caused by a low activity of bees around your garden or other helpful insects, this can also be caused due to a sudden change in temperature.
To provide better pollination for your These cucumber plant problems can be prevented by implementing a more beneficial and diverse arrangement of flowers and plants around your cucumber plant to encourage more insects to come all year round.

If your cucumber is bitter, it is possible that swings in temperature of 20 °F or more. You will tend to find that near the stem where the cucumber end was attached to the vine.
A good tip to lessen the bitterness of the cucumber would be to cut off the stem end and then peeling your fruit.

There are cucumber cultivars such as Diva that will reduce the chance of you getting a bitter cucumber.

Common diseases and pests

Alternaria leaf blight
There is a common cucumber plant disease called Alternaria leaf blight. You can recognize this disease when your cucumber plant turning yellow with spots. The spot on the leaves can also turn brown, with yellow or green around the spots. As the disease progresses through the leaves, the disease will leave holes.

The disease will become more of a problem in geographical areas where temperatures are higher along with more frequent rainfall.

The best practice to keep the disease at bay is to completely remove any signs of past cucurbits leftovers around the area that you plan on planting your cucumber plant. When you are watering your plant, make sure to water around the base rather than watering from above, to reduce wetness, which will prevent the escalation of the disease.

Anthracnose
Anthracnose has the leaves the appearance of round bruises, also leaving yellow on the edges of the leaves. This cucumber plant disease is more prone to spread in higher temperatures.

By applying a protective fungicide, will greatly reduce the rate of spreading.

Fruit rot
Fruit rot will have the appearance of brown or yellow blotches on the skin, with damp blotches on the skin that has been in contact with the soil. Other noticeable problems will include mold in the affected areas.

The disease will be more common in humid conditions.

Fruit rot can be best prevented by a better cultivation of the soil before planting. To create a barrier between the cucumber and the soil a plastic mulch should be used. Make sure to avoid unnaturally damp soil before beginning to plant your seedlings. When the plant begins to vine, a fungicide should be used for better plant protection.

Cercospora
You will notice that on the older leaves of the plant small brown spots. As the disease progresses there will be large areas of the leaf that will incur more bruising. The bruises could have a dark border. The bruises on the leaves could become fragile.

As this disease spreads by wind, the plant will need to be destroyed to prevent the continued spread to other plants.

Aster yellows
A cucumber plant turning yellow on the leaves with lower shoots growing out aggressively. Leaves could appear thickened and flowers will often become disfigured.

Infected plants that appear to be infected should be removed and destroyed.

Squash mosaic virus
There are different many symptoms of this disease, the most notable appearances may include vein banding, blotched leaves, circular spots, veins sticking out. Plants could become small and the cucumber could look deformed with freckled skin.

The most common form of virus transmission would be through seeds being infected and or transmitted by cucumber beetle.

Cottony leak
The first appearance of infection would be in the area of the growing cucumber, that is in contact with the soil with water spots. The spots will spread very fast to most of the cucumber leaving the cucumber soft.

The disease will be more prevalent in more wet conditions and will spread through the water and soil.

To help prevent this disease, mulching will help the prevention of this disease.

Cabbage looper
This is a problem that is caused by caterpillars, and the plant leaves will be damaged by large/small holes. The caterpillars have the appearance of a green body with white lines around the sides of their body.

You may use a chemical to try and keep the damage under control.

Flea beetles
Leaves will be damaged by small holes or a “shot-hole” appearance. Seedlings and young plants are more liable to be targeted.
The growth of the plant will be reduced, and in some cases may kill your plant. The culprit for this damage will be a beetle dark in color and have glossy skin.

Conclusion

There are many other diseases that we haven’t been able to cover here. The most common pests that will damage your plants are pickle worms, beetles, mites, whiteflies, and squash/vine borers.

Training your vines on a trellis or a fence will help keep the vines of the soil, keeping your fruit cleaner, and reducing disease. There are preplant and postemergence herbicides that are also available.