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Tomatoes pests and diseases

Published: 09.04.2023
pest/disease type symptoms on tomato control/prevention
Aphids Insect Stunted growth, curled leaves, sticky residue on leaves Spray with insecticidal soap, neem oil or use ladybugs to control aphid population
Whiteflies Insect Sticky residue on leaves, yellowing of leaves, wilting of plant Use yellow sticky traps, spray with insecticidal soap or neem oil
Tomato Hornworm Insect Large green caterpillar with white stripes on back, defoliation of plant, damages to fruit Handpick and remove from plant, use Bacillus thuringiensis (Bt) spray
Fusarium Wilt Fungal Wilting of plant, yellowing of leaves, brown streaks on stem Use resistant tomato varieties, rotate crops, avoid overhead watering
Verticillium Wilt Fungal Yellowing of leaves, wilting of plant, brown streaks on stem Use resistant tomato varieties, rotate crops, avoid overhead watering
Blossom End Rot Physiological Brown, sunken spots on bottom of fruit, caused by calcium deficiency Maintain even moisture levels, avoid over fertilizing with nitrogen, add calcium to soil
Early Blight Fungal Circular, brown spots on leaves, defoliation of plant Use resistant tomato varieties, remove infected leaves, apply fungicide
Late Blight Fungal Dark, water-soaked spots on leaves, stems and fruit, moldy growth on underside of leaves Use resistant tomato varieties, remove infected leaves, apply fungicide
Gray Mold/Botrytis Fungal Gray, fuzzy mold on leaves, stems and fruit, decay of plant tissue Provide good air circulation, avoid overhead watering, apply fungicide
Tomato Mosaic Virus Virus Mottled or streaked leaves, stunted growth, deformed fruit Remove infected plants, use disease-free seed and transplants
Tomato Spotted Wilt Virus Virus Yellowing and bronzing of leaves, ring spots on fruit, stunted growth Control thrips, remove infected plants, use disease-free seed and transplants


Aphids are small, soft-bodied insects that can infest tomato plants. They are typically green or black in color and can be found on the undersides of leaves and stems.


The presence of aphids can stunt plant growth, cause leaves to curl or yellow, and attract ants. They also excrete a sticky substance called honeydew, which can attract other pests like ants or cause sooty mold to grow on the leaves.

Control and Prevention

There are several ways to control and prevent aphids on tomato plants. One method is to spray the plants with a strong jet of water to dislodge the insects. Additionally, introducing natural predators like ladybugs or lacewings can help control the aphid population. Insecticidal soaps or neem oil can also be effective in controlling aphids.

Prevention is also key in avoiding aphid infestations. Regularly inspecting plants for signs of pests and practicing good garden hygiene by removing any debris or weeds that may harbor insects can help prevent aphids from taking hold.

In conclusion, while aphids can be a nuisance to tomato plants, there are several effective ways to control and prevent their infestation. By taking preventative measures and utilizing natural or chemical control methods, gardeners can keep their tomato plants healthy and pest-free.


Whiteflies are small, winged insects that are a common pest in tomato plants. These tiny bugs suck the sap from the leaves of the tomato plant, causing them to yellow and eventually die.

Symptoms of a whitefly infestation include yellowing leaves, sticky honeydew on leaves, and a general weakening of the plant. If left untreated, whiteflies can quickly spread to other plants in your garden.

To prevent whiteflies, it is important to keep your tomato plants healthy and strong. Regularly prune any damaged or diseased leaves, and remove any weeds or debris from around the plants. You can also use row covers to protect your plants from these pests.

If you do find whiteflies on your tomato plants, there are several ways to control them. You can use sticky traps to capture adult whiteflies, or spray your plants with insecticidal soap or neem oil. Another effective method is to introduce beneficial insects like ladybugs or lacewings into your garden, which will feed on whitefly eggs and larvae.

With proper prevention and control methods, you can keep whiteflies from ruining your tomato harvest and enjoy a bountiful crop.

Tomato Hornworm

Tomato Hornworm is a common pest that attacks tomato plants. They are the larvae of a moth and can grow up to 4 inches in length. These caterpillars are usually green in color with white stripes on their sides and a horn-like protrusion on their tail.


The damage caused by Tomato Hornworm includes holes in the leaves and fruit of the tomato plant. They can defoliate an entire plant in a matter of days, making it difficult for the plant to produce fruit. Additionally, they leave behind droppings, which can attract other pests and diseases.

Control or Prevention

To prevent Tomato Hornworm infestations, it's important to keep your garden clean and tidy by removing any fallen leaves or fruit. You can also use natural predators like birds or parasitic wasps to control the population. Alternatively, you can use insecticides like Bacillus thuringiensis, which is a natural bacteria that kills caterpillars.

If you notice Tomato Hornworms on your tomato plants, it's important to remove them by hand as soon as possible. You can also use a solution of dish soap and water to kill them. However, be careful not to damage the tomato plant while doing so.

In conclusion, preventing and controlling Tomato Hornworm infestations is crucial for a successful tomato harvest. With proper care and attention, you can keep these pests at bay and enjoy healthy tomatoes all season long.

Fusarium Wilt

Fusarium Wilt is a serious disease that affects tomatoes and is caused by the fungus Fusarium oxysporum. The fungus invades the roots of the tomato plant and causes the plant to wilt and die. It is a soil-borne disease that can remain in the soil for many years, making it difficult to control.


The first sign of Fusarium Wilt is yellowing of the leaves on one side of the plant. The yellowing will spread to the entire plant and eventually lead to wilting and death. The stem of the plant will also turn brown and become brittle. The fungus can also cause discoloration in the vascular tissue of the plant, which can be seen when the stem is cut open.

Control or Prevention

Prevention is key when it comes to Fusarium Wilt. It is important to use disease-free seeds and to rotate crops every year. If you have had Fusarium Wilt in your garden before, do not plant tomatoes or other susceptible plants in that area for at least 3 years. Proper soil drainage and irrigation can also help prevent the disease.

If your plants are already infected with Fusarium Wilt, there is no cure. Infected plants should be removed and destroyed immediately to prevent the spread of the fungus to healthy plants. Do not compost infected plants, as this can spread the fungus.

Verticillium Wilt

Verticillium Wilt is a fungal disease that affects a variety of plants, including tomatoes. The fungus lives in the soil and enters the plant through the roots, causing wilting and yellowing of the leaves.

Symptoms The first symptom of Verticillium Wilt is wilting of the lower leaves, which eventually turns yellow and dies. The wilting then spreads to the upper leaves, and the entire plant may eventually die. In addition, the stems may have brown streaks, and the fruits may be smaller than usual.

Control and Prevention Unfortunately, there is no cure for Verticillium Wilt once a plant is infected. The best course of action is to prevent it from occurring in the first place. This can be done by planting disease-resistant varieties of tomatoes, rotating crops each year, and practicing good soil hygiene by removing infected plants and debris.

If your tomato plants do become infected with Verticillium Wilt, it's important to remove them immediately to prevent the fungus from spreading to other plants. You should also avoid planting tomatoes in the same spot for at least 3 years.

Blossom End Rot

Blossom end rot is a common problem that can occur in tomato plants. It is a physiological disorder caused by a lack of calcium in the fruit. This problem can be identified by a dark, sunken area that appears at the bottom of the tomato fruit.


The first sign of blossom end rot is a small water-soaked spot on the blossom end of the tomato. This spot will eventually enlarge and turn black, becoming sunken and leathery. The affected fruit will then begin to rot and become unusable.

Control and Prevention

The best way to prevent blossom end rot is to ensure that your plants have adequate calcium. You can add calcium to your soil by using lime or gypsum. Additionally, make sure your plants are receiving consistent watering and avoid over-fertilizing.

If you notice any fruit with blossom end rot, remove it from the plant immediately to prevent the problem from spreading. Mulching around the base of your plants can also help regulate soil moisture levels and prevent this issue.

In conclusion, blossom end rot can be a frustrating problem for tomato growers, but with proper prevention and control methods, it can be easily managed. Always keep an eye on your plants and take action as soon as you notice any symptoms to ensure a healthy harvest.

Early Blight

Early blight is a common fungal disease that affects tomato plants, caused by the fungus Alternaria solani. It typically appears in warm and humid weather conditions and can spread rapidly if not controlled.

Symptoms: The first signs of early blight are small, dark spots on the lower leaves of the plant, which gradually enlarge and turn yellow with a concentric ring pattern. As the disease progresses, the leaves will wilt, turn brown, and eventually die. The fruits may also develop sunken lesions with concentric rings.

Control or Prevention: Early detection is key to controlling early blight. Remove infected leaves and debris from around the plants to prevent the fungus from spreading. Water at the base of the plants, and avoid overhead watering to prevent splashing of spores onto leaves. Consider using copper-based fungicides or neem oil to control the disease. Plant resistant varieties, such as 'Defiant' or 'Legend', or rotate crops to avoid planting tomatoes in the same spot every year.

In summary, early blight is a common fungal disease that can cause severe damage to tomato plants if not controlled. By taking preventive measures and promptly addressing any signs of infection, gardeners can keep their tomato plants healthy and productive.

Late Blight

Late blight is a devastating disease that affects tomatoes and other plants in the nightshade family, such as potatoes. It is caused by the fungus Phytophthora infestans and can quickly destroy an entire crop if left untreated.

Symptoms of late blight include dark spots on the leaves and stems, as well as a white mold on the undersides of leaves. The disease can spread rapidly, especially in wet conditions, and can cause the plant to wilt and die within a matter of days.

To control or prevent late blight, it is important to practice good garden hygiene by removing any infected plants or debris from the garden. Fungicides can also be used to treat the disease, but it is important to choose a product that specifically targets late blight and to follow the instructions carefully.

In addition, choosing resistant tomato varieties can also help to prevent the spread of late blight. Some popular resistant varieties include ‘Legend’, ‘Mountain Merit’, and ‘Defiant’. Regularly monitoring plants for signs of disease and taking action early can also help to minimize the impact of late blight on your tomato crop.

Gray Mold/Botrytis

Gray Mold, also known as Botrytis, is a fungal disease that affects many plants, including tomatoes. It can cause significant damage to both the fruit and the plant itself. In this section, we will discuss the symptoms of Gray Mold/Botrytis, its control and prevention measures.

Symptoms The first sign of Gray Mold/Botrytis is a gray fuzzy mold on the leaves or stems of the tomato plant. The fungus then spreads to the fruit causing it to rot and turn brown. You may also notice water-soaked lesions on the fruit or dark spots on the stems.

Control and Prevention To control Gray Mold/Botrytis, remove any affected plant parts immediately and dispose of them. Ensure good air circulation by spacing plants properly, and avoid overhead watering. Additionally, keep the soil surface clean and free from debris.

Prevention is key to avoiding this disease altogether. Choose disease-resistant varieties when planting your tomatoes, and ensure proper watering and fertilization practices. Monitor your plants closely, and immediately address any signs of disease.

In conclusion, Gray Mold/Botrytis is a common fungal disease that affects tomatoes. Early detection and prompt action are crucial in controlling its spread. By practicing good gardening habits, you can minimize the risk of this disease affecting your tomato crop.

Tomato Mosaic Virus

Tomato Mosaic Virus is a common disease that affects tomato plants. This viral disease can cause severe damage to the leaves, stems, and fruit of the plant, leading to reduced yields and even plant death.


The symptoms of Tomato Mosaic Virus include yellowing and curling of leaves, mosaic-like patterns on leaves, stunted growth, and a general decline in plant health. The fruit may also be deformed or discolored.

Control or Prevention:

To control or prevent Tomato Mosaic Virus, it is important to take several measures. Firstly, ensure that you buy certified virus-free seedlings. Secondly, maintain good hygiene practices by sterilizing your tools and washing your hands between plants to prevent spreading the virus. Additionally, remove any infected plants immediately and dispose of them properly.

It is also crucial to control the aphid population as they can transmit the virus. You can do this by using insecticidal soap or neem oil. Lastly, avoid planting tomatoes in the same spot for more than two years in a row as this increases the risk of infection.

By following these preventative measures, you can protect your tomato plants from the devastating effects of Tomato Mosaic Virus and enjoy a healthy harvest.

Tomato Spotted Wilt Virus

Tomato Spotted Wilt Virus (TSWV) is a common disease that affects tomato plants. It is caused by a virus that is transmitted by thrips, tiny insects that feed on plant sap. TSWV can cause severe damage to tomato plants and reduce yields.


The symptoms of TSWV can vary depending on the tomato variety and the stage of the infection. However, some common symptoms include:

  • Bronzing or yellowing of leaves
  • Stunting of plants
  • Necrosis or death of leaves, stems, and fruits
  • Rings or spots on fruits
  • Wilting of plants

Control or Prevention

There are several ways to control or prevent TSWV in your tomato garden:

  • Plant resistant varieties: There are some tomato varieties that are resistant to TSWV. Look for varieties labeled as "TSWV-resistant" or "TSWV-tolerant".
  • Remove infected plants: If you notice any signs of TSWV in your tomato plants, remove them immediately to prevent the spread of the virus.
  • Control thrips: Thrips are the main carriers of TSWV. Use sticky traps, insecticides, or beneficial insects like lacewings and ladybugs to control thrips in your garden.
  • Practice good sanitation: Clean up any plant debris or weeds in your garden to reduce the risk of thrips and TSWV.

By following these simple steps, you can prevent or control Tomato Spotted Wilt Virus in your tomato garden and enjoy a healthy harvest.

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!