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Radishes pests and diseases

Published: 09.04.2023
pest/disease type symptoms on radish control/prevention
Aphids Pest Yellowing or curling of leaves, stunted growth Use insecticidal soap or neem oil, introduce ladybugs or lacewings
Flea beetles Pest Small holes in leaves, wilting, stunted growth Use row covers, plant radishes after flea beetle peak season, use insecticides
Cutworms Pest Seedling death, stem damage Use collars around seedlings, handpick cutworms, use insecticides
Wireworms Pest Slow growth, yellowing, wilting Rotate crops, use bait traps, use insecticides
Clubroot Disease Stunted growth, yellowing, club-shaped roots Practice crop rotation, sterilize garden tools, use resistant varieties
Downy mildew Disease Yellowing, wilting, growth distortion Provide good air circulation, avoid overhead watering, use fungicides
Powdery mildew Disease White powdery coating on leaves, stunted growth Provide good air circulation, avoid overhead watering, use fungicides
Black rot Disease Yellowing, wilting, black and smelly roots Practice crop rotation, avoid overhead watering, use fungicides
Root maggots Pest Stunted growth, yellowing, small holes in roots Use row covers, remove infected plants, use insecticides
Whiteflies Pest Sticky white residue on leaves, stunted growth, wilting Use insecticidal soap or neem oil, introduce beneficial insects like ladybugs or lacewings


Aphids are small, soft-bodied insects that can cause serious damage to radish plants. These pests feed on the sap of the plants, causing the leaves to curl and distort. They also excrete a sticky substance called honeydew, which can attract other pests like ants and mold.

Symptoms: The most obvious symptom of an aphid infestation is the presence of small, green or black insects on the leaves and stems of the radish plant. The leaves may also appear curled or distorted, and there may be a sticky residue on the plant.

Control or Prevention: There are several ways to control or prevent aphids from attacking radish plants. One of the simplest methods is to spray the plant with a strong stream of water to knock off the aphids. You can also use insecticidal soap or neem oil to control the pests. Another effective method is to introduce natural predators like ladybugs or lacewings into your garden.

To prevent aphids from attacking your radish plants in the first place, make sure you keep your garden clean and free of debris. Prune any damaged or diseased leaves from your plants and avoid over-fertilizing, which can attract aphids. Additionally, try planting companion plants like marigolds or garlic, which are known to repel aphids.

By taking these steps, you can effectively control and prevent aphid infestations in your radish garden.

Flea Beetles

Flea beetles are small, jumping insects that can cause damage to radishes and other plants in the brassica family, such as broccoli and cabbage. They are most active in the spring and early summer when the weather is warm and can quickly cause significant damage to young plants.


Flea beetles leave small, round holes in the leaves of radishes, which can cause the plant to wilt and die if left untreated. The damage caused by flea beetles is usually more severe on younger plants, which have not yet developed a strong root system.

Control or Prevention

Preventing flea beetles from attacking your radishes is the best way to avoid damage. You can do this by covering your radishes with row covers or netting until they are well established. Planting radishes later in the season when flea beetle populations have decreased can also help.

If you already have a flea beetle infestation, there are a few things you can do to control it. One option is to use an insecticidal soap or neem oil spray to kill the beetles. Another option is to use yellow sticky traps, which will attract and trap the beetles.

In conclusion, flea beetles can be a pesky problem for radish growers. However, with proper prevention and control methods, you can keep your radishes healthy and thriving.


Cutworms are common pests that can damage various plants including radishes. These caterpillar-like pests can grow up to 2 inches long and come in different colors such as gray, brown, and black. Cutworms are usually active during the night and can be found hiding under soil clumps or debris during the day.

Symptoms of cutworm infestation in radishes include wilted or dead seedlings with cut stems near the soil line. Cutworms cut through plant stems, causing the plants to wither and die. It is important to identify and control cutworms as soon as possible to prevent further damage.

Preventive measures against cutworms include removing garden debris, tilling the soil in the fall to expose any pupae to winter temperatures, and using protective collars around plant stems. Biological control options include introducing parasitic nematodes that attack cutworm larvae.

Chemical control options include using insecticides containing Bacillus thuringiensis or carbaryl. However, these should be used as a last resort and with caution as they may harm beneficial insects and other wildlife.

Regular monitoring and early intervention are crucial in preventing and controlling cutworm infestations in radishes and other plants.


Wireworms are the larvae of click beetles and are a common pest for many root vegetables, including radishes. They are slender, cylindrical, and can range in color from yellow to brown. The wireworms feed on the roots of young plants, causing stunted growth or even death.

Symptoms: Young radish plants infected with wireworms often appear weak and wilted. The leaves may turn yellow and fall off. As the wireworms feed on the roots, they create holes that can lead to rotting or fungal infections.

Control and Prevention: There are several ways to control and prevent wireworm infestations in your garden. Crop rotation is an effective way to reduce the population of wireworms in your soil. Avoid planting radishes or other root vegetables in the same spot for at least three years.

You can also use beneficial nematodes to control wireworms. These microscopic worms attack and kill wireworms before they can cause damage to your plants. Additionally, you can set up bait stations using potato chunks or carrots to attract and trap the wireworms.

In conclusion, wireworms can be a frustrating pest for radish growers, but with proper prevention methods and control measures, you can keep your garden healthy and thriving.


Clubroot is a soil-borne disease caused by a pathogen called Plasmodiophora brassicae. This disease is commonly found in plants belonging to the Brassicaceae family, including radishes, cabbage, broccoli, and cauliflower. It causes the roots to become swollen and distorted, hence the name "clubroot."

Symptoms of clubroot include yellowing of leaves, stunted growth, and wilting of plants. The roots will become thickened and distorted, making it difficult for the plant to absorb water and nutrients. Clubroot can survive in soil for up to 20 years, making it difficult to control.

To prevent clubroot, rotate your crops regularly and avoid planting brassicas in the same area for at least three years. Make sure your soil pH is between 6.5 and 7.0, as acidic soil can increase the likelihood of clubroot. Additionally, avoid using infected soil or transplants.

If you suspect clubroot in your garden, remove infected plants immediately and dispose of them in a sealed bag. Do not compost them. Solarize the soil by covering it with clear plastic for several weeks to kill any remaining pathogens. Fumigation with methyl bromide is another option for severe cases.

In conclusion, clubroot can be a devastating disease for home gardeners growing radishes and other brassicas. However, by following preventative measures and promptly addressing any signs of infection, you can protect your crops from this harmful pathogen.

Downy Mildew

Downy mildew is a common fungal disease that affects radishes and other plants in the brassica family. The disease is caused by the fungus Peronospora parasitica, and it thrives in cool, damp conditions.


The first sign of downy mildew is yellowing and wilting of leaves, which may then develop into brown patches or spots. The underside of the leaves may have a fuzzy, grayish growth, which are the fungal spores. The infection can spread to other parts of the plant, such as the stem and roots, causing stunted growth and reduced yield.

Control or Prevention

Prevention is key when it comes to downy mildew. You can reduce the risk of infection by planting resistant varieties of radishes and practicing good crop rotation. Avoid planting brassicas in the same spot for at least two years.

If you do see symptoms of downy mildew, remove and dispose of infected plants immediately to prevent further spread. Use fungicides that contain copper or sulfur to protect healthy plants from infection. Be sure to follow the instructions carefully and apply the fungicide as soon as you notice symptoms.

In conclusion, downy mildew is a common fungal disease that affects radishes and other plants in the brassica family. Early detection and prevention are key to controlling this disease, so be sure to keep an eye out for symptoms and take action quickly if you suspect an infection.

Powdery Mildew

Powdery mildew is a fungal disease that affects a variety of plants, including radishes. It is most commonly found in warm, humid weather conditions and can spread quickly if not properly controlled.

Symptoms: The first sign of powdery mildew is the appearance of white, powdery spots on the leaves and stems of radish plants. As the disease progresses, these spots may merge and cover larger areas of the plant. Infected leaves may also become yellow or brown and eventually fall off.

Control or Prevention: Preventing powdery mildew is the best approach to control the disease. Ensure adequate air circulation around plants, avoid overhead watering, and maintain proper spacing between plants to reduce humidity levels. Regularly inspect your plants for signs of powdery mildew and remove any infected plant material immediately.

If you notice an outbreak of powdery mildew, a fungicidal spray can be applied to affected plants. However, it is important to note that fungicides are most effective when used as a preventative measure rather than as a cure for an already infected plant.

By being proactive in controlling powdery mildew, you can keep your radish plants healthy and productive throughout the growing season.

Black Rot

Black rot is a fungal disease that commonly affects radishes and other cruciferous vegetables like cabbage, broccoli, and cauliflower. It can be a serious problem for gardeners, as it can cause severe damage to the plants and even lead to crop loss if left untreated.


The first symptoms of black rot are small, black lesions that appear on the leaves of the plant. These lesions will gradually increase in size, and the infected leaves will turn yellow and die. The infection may also spread to the stem of the plant, causing it to become discolored and weakened. The roots of the plant may also be affected, becoming darkened and rotten.

Control or Prevention

The best way to prevent black rot is to practice good garden hygiene. Remove any infected plant material from the garden, including plant debris and weeds. Avoid planting cruciferous vegetables in the same location year after year, as this can lead to a buildup of fungal spores in the soil.

Fungicides can be used to control black rot, but they should be applied early in the growing season before symptoms appear. Copper-based fungicides are often recommended for organic gardening, but be sure to read the label carefully before using any chemical treatments.

In conclusion, black rot is a serious fungal disease that can cause significant damage to radishes and other cruciferous vegetables. By practicing good garden hygiene and using appropriate control measures, gardeners can prevent or manage black rot and enjoy a healthy harvest.

Root Maggots

Root maggots are common pests that can attack radishes and other root vegetables in your garden. These small, white maggots are the larvae of flies and they feed on the roots of plants, causing stunted growth and even death.

Symptoms: The first sign of a root maggot infestation is often wilting or yellowing leaves, as the maggots damage the roots and prevent the plant from absorbing enough water and nutrients. You may also see small tunnels or grooves in the roots themselves, which can lead to rotting and decay.

Control or Prevention: One way to prevent root maggots is to practice crop rotation, planting radishes and other root vegetables in a different location each year. You can also use row covers to physically block the flies from laying their eggs on your plants. If you do have an infestation, removing affected plants immediately and disposing of them away from your garden can help prevent further spread. Additionally, applying a layer of diatomaceous earth or a sticky trap can help catch adult flies before they have a chance to lay eggs.


Whiteflies are a common pest that can infest a variety of plants, including radishes. These tiny, winged insects feed on plant sap and can quickly multiply, causing damage to the leaves and stunting growth.


The most obvious symptom of whiteflies is the presence of the insects themselves. They are small, white, and can often be seen flying around the leaves of affected plants. Whiteflies also excrete a sticky substance known as honeydew, which can attract other pests and lead to the growth of black sooty mold.

Control or Prevention

Preventing a whitefly infestation is key to avoiding damage to your radishes. To prevent whiteflies, make sure to keep your garden clean and remove any dead or dying plants. You can also use yellow sticky traps to catch adult whiteflies.

If you already have a whitefly infestation, there are several control methods available. Insecticidal soaps or oils can be effective at killing whiteflies, as can neem oil. Additionally, introducing natural predators such as ladybugs or lacewings can help control the population of whiteflies.

In summary, while whiteflies can be a nuisance in the garden, there are several effective methods for preventing and controlling them. By keeping your garden clean and using natural pest control methods, you can ensure that your radishes stay healthy and pest-free.

Author: Michael Chen
Bio: I'm gardening specialist with a mission to empower people to grow their own fruits and vegetables. With my background in Plant Science from the University of California and experience working with farmers and community gardens, I'm dedicated to promoting sustainable agriculture practices and helping individuals achieve bountiful harvests. Let's get growing!