Mosaic viruses can be devastating, and they affect over a hundred and fifty different types of plants. Among these are a wide variety of ornamentals, fruits, and vegetables.
This type of disease can be recognized by the mottling of leaves in dark and light green, yellow, and white shades. This streaking effect is the source of the name “mosaic” virus.

Susceptible plants most often infected by mosaic viruses include:
- Cauliflower
- Cucumbers
- Tomato Mosaic Virus
- Tobacco Mosaic Virus
- Squash
However, this is just a small sampling of the plants that can be devastated by these diseases. In this article, we discuss mosaic viruses and share advice on preventing and controlling them.
What Are The Most Common Mosaic Plant Viruses?
Some of the different types of mosaic virus that may affect your garden plants include:
- Bean Common Mosaic Virus (BCMV)
- Bean Yellow Mosaic Virus (BYMV)
- Cucumber Mosaic Virus (CMV)
- Tobacco Mosaic Virus (TMV)
Aphids usually spread bean mosaic viruses, but they can also be spread in the seed. Therefore, if your beans are infected with the mosaic virus, you should not save seeds from these plants for your next year’s crop.
Cucumber mosaic virus is very common and affects a wide variety of plants, including:
- Cucumbers
- Squashes
- Tomatoes
- Peppers – Bell Peppers and Chile Peppers
- Eggplants
- Potatoes
- Lettuces
- Spinach
- Melons
Aphids typically spread this type of mosaic virus.
Tobacco mosaic virus can spread through seed, touch, and the use of tobacco products.
What Are The Symptoms of Mosaic Virus?
It can be hard to tell one type of viral disease in plants because the symptoms are very similar.
Additionally, symptoms of viruses can vary from one type of plant to another, one age of plant to another, and during different sorts of weather.
Here are a few common symptoms to watch for:
- Stunted plant growth and fruit yields may be reduced.
- Fruit that has been infected with a mosaic virus may look warty and have spotted, yellowed areas.
- Stunted, blistered-looking leaves mottled with light and dark green, yellow, and white spots.
- Leaves that are curled, crumpled or otherwise deformed
- Overall failure to thrive
- Yellowed leaf veins
In the cucumber mosaic virus, you may notice that the edges of leaves do not form correctly and that the veins of the leaves grow long and narrow. This is called shoestring syndrome.
In the tobacco mosaic virus, you may notice that existing growth exhibits classic mottling and that new growth is deformed and twisted.
What Can You Do About Mosaic Viruses?
There is no way to cure mosaic viruses, but you may be able to mitigate the damage. Follow these smart tips.
- Begin by removing any plants that show symptoms. Unfortunately, you cannot cure them, and you must destroy them. Be sure to burn them or dispose of them in sealed garbage bags. Never compost diseased plants.
- Keep a close eye on all your other plants and remove them promptly if they begin to show symptoms.
- Be sure to wash your hands between plants whenever you handle or work with your plants. Likewise, you must disinfect your tools between plants using a bleach solution or boiling water.
- Prevent Mosaic viruses from getting a foothold in your garden by looking for plant varieties that are virus resistant. Plants that are typically very susceptible to mosaic viruses include:
– Watermelons
– Green Beans
– Cauliflower
– Cucumbers
– Tomatoes
– Zucchini
Although there are no tomatoes that are currently resistant to cucumber mosaic virus, any variety resistant to other types of the mosaic virus will have some defense against cucumber mosaic virus.
- Be sure to keep pest insects under control because they are significant spreaders of mosaic viruses. The main culprits are leafhoppers and aphids. Taking steps such as using floating row covers and aluminum foil mulch can help keep these insects away from your plants.
- Keep weeds under control. Mosaic viruses can impact weeds, and this only supports their spread. Additionally, insects that feed on weeds can move to your plants and spread the virus.
- Clear all garden debris at the end of the season because mosaic viruses can overwinter in dead weeds, piles of garden rubbish, and even in the soil.
- Always purchase disease-free seed, or treat your garden seed by soaking it in a 10% bleach solution before planting it.
- Mosaic viruses can be spread by a wide variety of pest insects, such as:
– Cucumber beetles
– Leafhoppers
– Whiteflies
– Aphids
Establish an ongoing pest insect control program to enlist the aid of beneficial insects and safe products such as diatomaceous earth and insecticidal soap. Use physical barriers, such as row covers, to keep pest insects away from your plants.
- Substances and equipment that have come in contact with mosaic viruses can spread them, so take care with:
– Gardening equipment
– Starter pots
– Containers
– Seed
– Soil
Additionally, divisions and cuttings from infected plants will naturally carry the infection.
- Sterilize all tools and equipment after use. Remember that this includes tools and worktops, pots and containers, fencing in trellises, ties, stakes,, and the like.
- Take care not to work in your garden during wet weather. When leaves are damp, it’s easier for viruses to brush off your clothing or hands and be carried to uninfected plants.
- Keep your garden tobacco-free. The use of tobacco products in the garden can spread mosaic viruses, especially tobacco mosaic viruses.
- Be vigilant! As with all viruses, prevention is the best cure. There is no actual cure for mosaic viruses or any other virus. You must prevent them from taking a foothold by practicing stringent sanitation, monitoring your plants vigilantly, and carefully choosing plants that are disease-free and disease resistant.