Tobacco Mosaic Virus

You don’t have to grow tobacco to have reason to worry about tobacco mosaic virus. 


Tomatoes are highly susceptible to this disease that can be carried on tools, clothing, cigarettes, and, yes, even the saliva and other bodily excretions of smokers. This tenacious virus can stay alive even after its host is dead, and it can withstand extreme temperatures. 

Tobacco mosaic virus symptoms on orchid leaves (USDA Forest Service) Public Domain

Tobacco mosaic virus host plants

In addition to tomatoes and tobacco, the tobacco mosaic virus (TMV) has been found on over 350 different plant species, including cucumbers, many flowers and ornamental plants, and all members of the nightshade family, such as eggplant, potatoes, groundcherries, tomatillos, and peppers.  While they may not show symptoms, grapes and apple trees can also become infected.


Symptoms of tomato mosaic virus

Tobacco mosaic virus starts out as nothing more than paler than normal green between the veins of young leaves. This lightened area quickly becomes mottled, leaving a green, white, or yellow mosaic pattern. Bumpy wrinkles may also appear, in a behavior known as rugosity, and leaves may appear distorted or stringy, or exhibit cupping.


​Leaf veins may also turn yellow, and yellow streaking on the leaves may also occur. Many of these symptoms can be mistaken for signs of chemical overspray, but the mosaic pattern is usually distinct enough to rule this out. While this disease does not kill plants, it can stunt them severely. Infected leaves soon die, leaving dead patches in the plant and reducing production by up to 20%. Fruit that is produced is often discolored and deformed.

How is tobacco mosaic virus spread?

Unlike many other diseases, which are spread by sap-sucking insects, such as thrips and aphids, tobacco mosaic virus is mostly spread by direct contact. Tobacco mosaic virus has also been spread by chewing insects, such as grasshoppers and caterpillars, and by bumblebees, as they pollinate flowers.


Preventing tobacco mosaic virus

Plants infected with tomato mosaic virus must be removed and destroyed. According to the  Michigan State University Extension, you can prevent the virus from moving onto uninfected plants by spraying them, just before transplanting, with a 20% nonfat dry milk solution. This spray can also be used on containers, walkways and other surfaces. The milk solution coats the virus, rendering it inactive. The milk treatment only works while the milk is wet.


These other tips can also help reduce the likelihood tobacco mosaic virus in your garden:

• Quarantine all new plants until you are certain they are pest and disease-free.
• Buy disease resistant varieties, especially when shopping for heirlooms and hybrids.*
• Wash your hands before working in the garden.
• Wear garden shoes, and not street shoes, when working in the garden.
• Avoid taking cuttings from potentially infected plants.
• Crop rotation can help break the disease triangle, though this virus is tough.

*Check plant labels for the letters V, F, N, T or A. These symbols indicate a resistant to verticillium wilt, fusarium wilt, nematodes, tobacco mosaic virus or alternaria stem canker, respectively.


According to a study conducted by the National Institutes of Health, all brands of cigarettes studied tested positive for tobacco mosaic virus, while only 53% of those viruses were viable. Also, 45% of the saliva samples taken from smokers tested positive for tobacco mosaic virus. So, smokers and users of other tobacco products, please wash your hands before entering your (or someone else’s) garden, and always throw your butts in the trash. Thank you.