Mosaic Viruses

How to Identify, Control, and Prevent Mosaic Viruses

Mosaic Virus

Here are tips on how to identify, control, and prevent mosaic viruses on a variety of plants.

What Are Mosaic Viruses?

Mosaic viruses affect more than 150 types of plants, including many fruits, vegetables, and flowers. The disease is characterized by leaves that are mottled with yellow, white, and light or dark green spots and streaks (in other words, a “mosaic” of these colors). Some of the most commonly infected plants include tomatoes, squashes, cauliflower, and cucumbers, but many more plants are susceptible.

Types of Mosaic Viruses

There are a number of mosaic viruses that commonly affect plants in the vegetable garden, including:

  • Bean Common Mosaic Virus (BCMV) and Bean Yellow Mosaic Virus (BYMV) are the primary mosaic viruses that affect beans of all types. They are typically spread by aphids, but BCMV is also seed-borne, so do not save seeds from infected plants. 
  • Cucumber Mosaic Virus (CMV) is one of the most common types of mosaic viruses and tends to be spread by aphids. As can be inferred from its name, cucumber mosaic virus often affects cucumbers, but it is also a common problem for many other garden plants, including other cucurbits (melons, squashes), nightshades (tomatoes, peppers, eggplants, potatoes), and leafy greens (lettuce, spinach).
  • Tobacco Mosaic Virus (TMV) spreads through seeds and direct contact, and the best way to avoid it is to grow resistant varieties. 


How to Identify Mosaic Viruses and Damage

Viral diseases are difficult to identify because symptoms vary from plant to plant and may also vary depending on the age of the plant and its growing conditions. However, the most common ways of identifying mosaic viruses are listed below.

  • The leaves are mottled with yellow, white, and light and dark green spots, which appear to be elevated. This gives the leaves a blister-like appearance.
  • Plants are often stunted, or they grow poorly.
  • Plants may have other deformities and their leaves may be crinkled or wavy. 
  • Cucumber mosaic virus: Infected plants are stunted and often exhibit “shoestring sydrome,” which is a characteristic malformation in which the edges of the leaves fail to develop, with the leaf veins developing as long, narrow strips. Tomatoes are small and misshapen.
  • Tobacco mosaic virus: Infected plants have mottled and yellowed leaves and twisted or deformed young growth.

Photo Credit: University of California. Cucumber mosaic virus causes severe damage and discoloration to a spinach plant.

Control and Prevention

How to Control Mosaic Viruses

Once plants are infected, there is no cure for mosaic viruses. Because of this, prevention is key! However, if plants in your garden do show symptoms of having mosaic viruses, here’s how to minimize the damage:

  • Remove all infected plants and destroy them. Do NOT put them in the compost pile, as the virus may persist in infected plant matter. Burn infected plants or throw them out with the garbage.
  • Monitor the rest of your plants closely, especially those that were located near infected plants.
  • Disinfect gardening tools after every use. Keep a bottle of a weak bleach solution or other antiviral disinfectant to wipe your tools down with.

How to Prevent Mosaic Viruses

  • Plant virus-resistant varieties in your garden. Resistant varieties of tomatoes have yet to be developed for cucumber mosaic virus, but tomatoes that are resistant to tobacco mosaic virus may have some slight resistance to cucumber mosaic virus as well.
  • Mosaic viruses are mostly spread by insects, especially aphids and leafhoppers. You can try covering your plants with a floating row cover or aluminum foil mulches to prevent these insects from infecting your plants. Look at our other tips for controlling aphids.
  • Control your weeds. Some types may serve as hosts for the disease, and when aphids and other insects feed on these plants, they will spread the viruses to your garden plants.
  • To avoid seed-borne mosaic viruses, soak seeds of susceptible plants in a 10% bleach solution before planting.


Reader Comments

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Mosaic Virus

I have had a problem with this virus for three year, starts in my potatoes then to beans and then to tomatoes. Complete new bed this year and soil, and still my early potatoes are showing the sign of the virus. Are you saying pull all those plants out but then what can I do to the bed to try and eradicate it regards Jeff

Josta berry leaf disease

I planted one Jostaberry bush beside my red currants. It's leaves (top surface) are now covered with tan colored lines along the leaf veins. The leaves are green but for the tan areas. There is no other color, spots or mildew. If this is a virus, should l just dig up the Jostaberry bush and burn it? It was planted this spring, saw no flowers/fruit. The bush is about 4' tall. Thanks for your help.

Jostaberry Bush Mosaic Virus

The Editors's picture

Hi Kathy,
It’s hard to tell at that stage if the bush is infected with mosaic virus, so wait and monitor it closely. If the leaves continue to show signs over the next week, the smart move is to be proactive and dispose of the plant before others nearby get infected.


Gday mate I was clearing out some soil of a plant which I didnt know had mosaic. At this stage im still not too sure so but nonetheless, I poured the soil indiscriminately into my backyard. Any tips?

tobbacco mosaic virus effects on tomato plant withinn 14 days

Please can you outline the effects of tobbacco mosaic virus on tomato plant within 14 days of innoculation

Safe to plant trees in affected area?

Last year, my tomato and cucumber plants had the mosaic virus. I'm moving the veggies to another spot this year, but is the soil safe for planting trees? I'm thinking fruiting trees, or a magnolia or a crepe myrtle? Would the mosaic virus spread to fruit?
Thank you!

Planting in Infected Soil

The Editors's picture

There are several different types of mosaic viruses, and without knowing which one affected your veggies, it’s impossible to tell what type of plants the virus might infect in the future. Generally, they have a wide range of host plants, so it’s likely that the virus would persist in whatever you plant next. Therefore, we would recommend avoiding planting anything in that spot for the time being. Clear out the patch of all plant matter (including roots) and burn it, if possible (do NOT put it in your compost pile). Let the plot sit empty for at least a year (two is better), and then try planting again. You may want to look into buying mosaic-virus–resistant vegetable varieties for an extra layer of protection.

Squash mosaic disease

So my zucchini and pumpkin has mosaic disease. I took them out of the garden. My questions are how long can the virus live in the dirt? When would it be safe to plant susceptible plants in that row of dirt again? And also what are some veggies if any that I can plant in there now to get a fall harvest? Or good ones to plant in that dirt next spring?

planting after mosaic virus

The Editors's picture

Sorry to hear the news. The mosaic virus can overwinter in the roots of perennial weeds, flowers, and some crops plants. It grows with the plant in the spring, appearing in the upper leaves. However, it can not live in extremely dry conditions. As for planting now, avoid plants varieties that are susceptible to the cucumber mosaic virus; grow resistant cultivars and use resistant seeds. Consider using row covers to prevent aphids from reaching plants in the first place (aphids bring on CMV). This page from the Tennessee cooperative extension service provides a list of vegetables and varieties and resistance:

You might get more information from your local cooperative extension service. Search for your state here and find the resources:

Mosaic virus

Would parsley and raspberries be susceptible to the mosaic virus? I see some new growth that is spindly with twisted stunted leaves. Would pruning out infected growth on the raspberries help control? Thanks for your reply in advance.

Mosaic Virus in Raspberries and Celery

The Editors's picture

Yes, mosaic viruses can affect both raspberries and celery. Cutting out infected material can slow the virus’ spread to adjacent plants, but it will not cure the infected plant. Unfortunately, once a plant has contracted a mosaic virus, it will always be infected. 


i have a container garden inside of a screened enclosure and I know my cucumber plant has the CMV. Would the aphids have been able to get to the plant inside the screen, or were they already on the plant when I bought it? The plant still grows and the new growth stays nice for a few days but eventually the leaves get the same pattern and the small yellow flowers wilt and die off. Im guessing this will continue so my only option is to rid of the entire plant?

Cuke with the virus

The Editors's picture

Sad to say, there is no cure, no fix. As for the origin, it could have been aphids already in the plant or the plant could have been infected before you purchased it by the people who handled it or their tools.

Mosaic Virus

My infected tomatoes and peppers (mosaic virus) are all grown in pots, and irrigated via drip irrigation.
1. Am I correct in assuming that, since my tools need disinfection (my hands!), that I will have to toss out my SOIL and disinfect or replace my irrigation lines and drips? Will soap and water suffice for the pots and drips?
2. My herbs (basil and mint) grew side-by-side with my tomatoes and peppers. Should I be treating them the same? I'm assuming so (but don't know), because I don't think that aphids, etc., are non-migratory...


Mosaic virus treatment

The Editors's picture

The TMV (tobacco mosaic virus) transmits extremely easily, so to your second question, yes, treat all of your plants, especially those that are/were side-by-side with the tomatoes and peppers.

About your first question…yes, toss out your soil and all tools should be washed. If your drip irrigation equipment cam in contact with the infected plants or soil, it should be washed.

Mosaic virus

Is it not possible for plants to become infected without ever seeing an aphid? Does it not blow in the wind, or transmit by other insects?

Cucumber diseases/virus caused by yellow beetles

If my plant has been infected is the food edible still or not?

infected fruit

The Editors's picture

We suggest that when in doubt, throw it out, especially if the harvested part is a part that is directly affected, such as leaves. If fruit shows no blemishes, it might be OK to eat it, even if the rest of the plant shows symptoms. Some diseases only cause cosmetic damage to the fruit, not internal, and would be fine to eat. Others, though, that attack the interior of the fruit will likely, at the very least, affect quality and flavor. Most plant diseases are not transferable to humans. Some bacteria, etc., are, however, or some fungi, although not harmful directly, can produce compounds that are. If a plant is weakened, secondary infections may also arise.

Tomato Virus

It appears my garden has the Tomato/cucumber virus. It started on my cucumber mottled marks on leaves, that eventually dry out. The cucumber started fruiting early and I have 2 nice cucumbers but the new growth flowers and then the new fruit goes nowhere. I have lots of new growth, but the leaves dont last long. My tomatoes have been loaded with fruit. I have been enjoying beautiful cherry tomatoes for about 2 weeks. Last week I noticed a few spots on the leaves and then almost overnight the plants are covered. I am still getting ripening tomatoes but the leaves themselves are almost all brown. My peppers are at the other end of the garden and are starting to show some spots of yellow. The peppers are bountiful and starting to ripen.

I live in Central Florida and am gardening in Straw Bales. Because I garden in my backyard I have one long row of plants. Tomatoes, cucumbers, Green beans. peppers (with herbs in between), The only thing not showing leaf distress are the green beans. I have used Neem oil to control insects as well as ladybugs. The only insect I have found was the squash vine borer in my zucchini. All the infected plants were removed. I have not seen aphids.

After days of research, it seems like my garden is done for now. I will remove all the plants, straw bales, and ground cover. My question would be concerning the metal poles, tomato cages, wire trellis, drip lines and garden equipment. Can everything be disinfected with bleach water? I read one suggestion of covering everything with liquid milk. The garden area is between a wooden fence and the house, do I need to bleach these down too? Can I clean the area and work on a new garden in the fall or maybe even some summer crops or are my backyard garden days over?

virus prevention

The Editors's picture

Viruses enter through wounds - such as feeding insects, pruned stems, etc. Some can also travel via infected seeds. If your tomato/cucumber has cucumber mosaic virus (CMV), this is spread by aphids and by contaminated tools, etc. Clean your tools regularly with a 10-percent bleach solution (cleaning your wire cages, poles, trellis, and other equipment might be helpful as well before next growing season, but you don’t need to do the fence or house) and use row covers to discourage insects from transmitting the disease to healthy plants. Wash hands often with soap and water. Destroy all infected plants (do not compost) and also remove weeds–many can harbor viruses, or attract insects that transmit them. Control aphids; silver-reflective mulches can help repel them. Choose cucumber resistant to CMV. Splash up from infected soil should be curbed by your straw bale method.

For other viruses, the same advice stands: disinfect your tools, or soak rowcovers in the 10 percent bleach solution. Choose resistant varieties, if available. Remove weeds. Remove any diseased plant promptly. Wash hands thoroughly before handling different plants. To avoid tobacco mosaic virus, do not use tobacco products near the garden. Rotate crops each year.

You should be able to still grow a garden each year if you keep up with these precautions. Most viruses are transmitted actively by a vector, mainly feeding insects, so if you control those, or prevent their damage, then you may be fine.



Hi Gary,

The Editors's picture

Hi Gary,

You didn’t mention if you had blooms. Bean blossoms will drop from the plant if the weather is too hot and too much nitrogen in the soil will prevent pods from setting. High humidity can also cause bloom drop. Go to our beans page at for more information about growing and caring for bean plants.

I'm having a real bad start

I'm having a real bad start to spring! I had bought Merical Grow Organic planting items, several differant things made by them. I then attempted to start everything by Certified organic seed, I planted the seeds in an eggshell to get really healthy strong roots, peppers were planted with 2 match sticks and fetilizer, peas were planted in the potting soil mix. Well ending result to this was alot of little knats on the pepper pods and the peas took off in 2 days, sprouted and then turned yellow then died. I then called a nursery to see if they sold Certified Organic plants, I was told yes and went to get them brought them home found out they were NOT Certified at all! They may have been Organic but they were not Certified anyhow come to find out the strawberry p[lants had aphids and the leaves on the peppers, tomatoes, broccoli and cucumbers all had signs of discolored yellow leaves, drying fron tip of leaf and leaves curling downward, I had planted one of the strawberry plants in a 5 gallon self watering bucket, planted banana pieces into soil 2" down and aphids up and left shop. I had cut most of the bad leaves off the tomatoes, peppers are wilting in seedling pots, broccoli is inside under grow lights with most of the peppers and a few tomato plants, the cucumbers and a few tomatoe plants are outside. The only plant that is planted is the one Fresca strawberry plant, I live in zone 3 in MD and the weather here is crazy nice one day, snow, rain and cold another, I am doing self watering, planting by the moon and loosing my mind with the plants that i bought. HELP!!! ANYONE!

It's better to wait until the

The Editors's picture

It's better to wait until the weather is warmer to put any of the warm weather veggies outside. It's too early to put tomatoes and cucumbers outside in zone 3. You can plant peas, spinach, kale etc. in the garden now. They don't mind a few cold nights and days. For aphid control check out our pests page at Don't fertilize young seedlings too much. Wait until they are transplanted outdoors.

I have had some of the same

I have had some of the same issues-my seedlings did great until just recently some of them are srarting to spot and some look chewed on
I know that fertilizing seedlings when too young can damage or kill the plants, so I mixed organic potting mix with equal parts organic topsoil and some peat moss and perlite. I avoided buying kinds containing fertilizer. since it can be difficult to distinguish between fungi, bacteria, insect infestation (my eyes aren't too good anymore) I chose to treat with Neem oil. you can get it many places (lowes,home depot) and isn't expensive. Dilute 0.5 Tbsp per qt H2O and spray on plants.
Neem is made from vegetable matter
I hope this helps

I had a very similar issue a

I had a very similar issue a few years ago with Miricle grow. I was repotting all of my house plants, as I do each year with Miricle Grow potting soil. A few days later I thought i had fruit flies. So I put out traps and none were going for it...more research...they were fungal gnats...apparently a known problem with Miricle Grow...more research...removed all soil, washed off roots of what I could save and use black gold more gnats...if you are interested research'll be angry.

Used to love them, now I will never use any of their product again.

So im a first time gardener

So im a first time gardener and I was reading the posts here about all the viruses and thing that affect plants. My question is should I end up with any of these an not know it and consume the veggies or fruit will it harm me ir my family?

Plant viruses do not

The Editors's picture

Plant viruses do not replicate or cause infection in humans or other mammals.

My tomato plants first turned

My tomato plants first turned yellow and then wilted and now have purple coloring on them and some leaves have holes. The zinnia and sunflower in the adjacent pot also seems to have been infected. However, the tomatoes are very small but do ripen. My question is: Is it safe to eat the tomatoes from this plant (assuming it is infected based on above responses) if thoroughly washed and cooked in heat?


After removing infected

After removing infected plants, what about the soil in raised planter beds? Does mosaic virus overwinter in the soil to infect the following year as well? Is there any preventative that is effective?



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