Plant Diseases That Affect Cucumbers and How to Treat Them

Updated on December 30, 2016

If your cucumber plants are wilting, they may be infected with bacterial wilt disease. A white mosaic pattern on the leaves indicate cucumber mosaic virus. If you see small, yellow spots on the leaves that rapidly decay, leaving raggedy edged holes, your plants may have the fungus known as anthracnose.

These three cucumber plant diseases are commonly seen in home gardens. Treatment of these conditions is limited, but good preventative practices will help reduce the risk to your cucumber plants.

Bacterial Wilt Disease

The cucumber beetle is a small insect, yellow in color with either black stripes or spots on its back. It carries the bacteria that cause bacterial wilt disease, injecting the bacteria into the plant as it feeds. The plants' leaves wilt, the vines wither, and within a brief period the plant dies.

Prevention is one of the better controls for this disease. The beetles are repelled by tansy, catnip and radish plants. Include these in your garden in close proximity to your cucumber plants.

Look for the beetles on your plants in early evening. Remove and kill them. Dispose of the bodies in a plastic bag. Keep the garden soil free of weeds, as cucumber beetles also feed on these.

Unfortunately, there is no treatment when a plant is infected. If you suspect a plant suffers from bacterial wilt, cut a wilting stem near the base and place in a glass of water. If you see milky-looking strands emerge from the cut, the plant is infected, and should be removed from the garden.

Evidence of Cucumber Mosaic Virus
Evidence of Cucumber Mosaic Virus | Source

Cucumber Mosaic Virus

Aphid and cucumber beetle control is essential in preventing cucumber mosaic virus. This disease presents as a thin pale yellow or white lines on the surfaces of leaves. The overall effect is one of a mosaic pattern on the leaves.

Use insecticides containing carbaryl and methoxychlor at the first sign of aphid infestation on any of your plants. If you're reluctant to apply chemicals, spray the plants with a mixture of crushed garlic, a few drops of dish soap and four cups of water. Spray the plants with a strong spray from the hose after two hours to remove the bugs.

If you spot the virus on a young seedling, remove the infected leaves and spray the plant with a mild dish soap and water solution. This may halt the spread, but if it persists, remove the plant from the garden.


A fungus, anthracnose infests cucumber plants during warm, wet weather. Small, yellowish spots appear on the leaves and turn brown. Brown streaking develops along the stems. Any fruit present may develop a pinkish, oozing bruise. This bruising is actually anthracnose spores.

At the first signs of anthracnose apply a fungicide spray containing benomyl and chlorothalonil. This may stop the spread of the fungus on the plants. The fungus, though, spreads rapidly and is resilient. If the spots on the leaves have already deteriorated and streaking is evident, pull the plant from the garden and dispose of properly.

Cultural Practices

The application of pesticides and home remedy treatments aid in pest control, but preventative measures should also be used, such as companion planting and controlled irrigation. Use drip irrigation or soaker hoses so as to avoid getting the plant leaves and stems wet. This reduces the change of anthracnose and mildew diseases.

Obtain your seeds and seedlings from a reputable dealer. Poorly cultivated seeds can also carry viral and fungal infections and infect other plants in your garden.

Use row covers during rainy weather. If the plants are too large, add portable sun shades to the garden area to reduce the risk of anthracnose.

The risk of cucumber plant disease can be reduced by employing preventative measures. If you do suspect infections, act quickly as this may keep the disease from spreading throughout your garden.


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    • profile image

      Gode 2 months ago

      Thanks for the cucumbers advice

    • profile image

      Paul 5 months ago

      Please am having problem with my plant the leaf is having yellow dot what am to do?

    • profile image

      Michel Haddad 10 months ago

      My cucumber Plant Have Somme Yelow insect What should I do

    • profile image

      lori 4 years ago

      Thank you very much for your convenient information on cucumber diseases and their solutions I know am gonna pass my sba thanks again

    • Shelly McRae profile image

      Shelly McRae 5 years ago from Phoenix, Arizona

      Hello Donna. Sorry to hear about your squash beetle problem. They do terrorize a garden. I had an issue some years back- drove me crazy they did. Thanks for taking the time to comment.

    • DonnaCosmato profile image

      Donna Cosmato 5 years ago from USA

      Great tutorial, Shelly! I didn't plant any cucurbits this year because of the squash beetle problems we are experiencing in my region, but I bookmarked it for future reference. Voted up.