Does Aspirin Really Help Tomato Plants? How to Use it?

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In Brief: Is Aspirin Good for Tomato Plants?

The active ingredient of aspirin, salicylic acid, may mimic the natural growth hormone in plants. Some scientific studies have documented the benefit of salicylic acid in increasing disease resistance and plant yield in tomatoes. However, the use of aspirin in deterring pests, seed germination, and stress tolerance is inconclusive. More studies are required in the future.

This article will help you decide if aspirin is beneficial for tomato plants.

I attempt to answer this question based on research papers and my personal experience in growing tomato plants.

Shall we get started!

Science Behind Using Aspirin on Tomato Plants

Aspirin is gaining popularity amongst gardeners. The active metabolite of aspirin is salicylic acid. It is touted for triggering the immune response of the plants against pathogens.

Aspirin, also known as acetylsalicylic acid, is normally used to treat human diseases. It is also gaining popularity for its gardening benefits.

Some gardeners use aspirin for tomato plants and have had better growth in aspirin-treated plants. So, what is the science behind using aspirin for tomato plants?

The plants produce a key defense hormone, salicylic acid when they are stressed to cope up. It induces the immune system of the plants and protects them from diseases and insects.

The metabolite of the aspirin is salicylic acid. It behaves like a plant hormone and promotes growth in plants.
Also, it induces the plant`s defenses against diseases and protects the plants from infections.

There are many claims that aspirin benefits tomato plants. Some of these claims are supported by science, while
others are not.

Claims Of Adding Aspirin To Tomato Plants – Truth vs Myths

In this subsection, let us analyze the benefits of aspirin to tomato plants and if these claims are supported by science. We will see if this common medicine can become one of the important garden essentials.

1. Aspirin Prevents Incidence of Disease

Salicylic acid may induce the SAR response in tomato plants. It will encourage the tomato plants to use their defense systems. It may prevent the incidence of diseases but may not treat the diseases.

Systemic acquired resistance (SAR) is a mechanism of induced defense that helps plants to defend against pathogens. It requires the release of a signal molecule, salicylic acid.

Different studies showed that salicylic acid triggered the SAR response in response to a disease pathogen. It will encourage the plants to fight against the infection using their defense system.

A study showed that a higher aspirin level may reduce the incidence of disease in tomato plants.

In another study, pre-treating the potted tomato seedlings with salicylic acid may prevent phytoplasma infections. It was suggested that salicylic acid triggered SAR against the pathogens.

Most of these studies are done with salicylic acid and not aspirin. So, the effective dose of aspirin in protecting tomato plants against pathogens is not clear.

Also, it may help in preventing disease. It may not work after the tomato plant is affected by the pathogen. In short, it will not treat the affected plants.

2. Aspirin Increases Plant Size And Yield

Some preliminary studies showed that foliar aspirin spray had some impact on the growth and yield of tomatoes. Future studies will confirm if aspirin can increase the tomato plant yield.

A study showed that aspirin spray (120 ppm aspirin) had a positive impact on tomato plant growth and production.

Another study conducted by the International Society for Horticultural Science showed that salicylic acid increased tomato plant yield.

The tomato plants were sprayed with different concentrations of foliar salicylic acid four times at 10-day intervals, two weeks after planting. There were improvements in plant growth, early yield, and total yield.

Aspirin may help the plant deal with the stress and grow well. However, the available research is limited if it improves yield in unstressed plants.

3. Aspirin Induces Multiple Stress Tolerance In Tomato Plants

One study showed that tomato plants grown from seeds soaked in salicylic acid, displayed resistance to heat, cold, and drought. More studies are warranted to confirm aspirin-induced stress tolerance.

A study showed that a physiological concentration of salicylic acid may confer stress tolerance in tomato plants.

The seeds were soaked in salicylic or acetylsalicylic acid and then sowed. The grown plants displayed tolerance
to heat, cold, and drought.

The present studies are not enough to confirm if the aspirin may trigger heat-cold tolerance and drought resistance in tomato plants. Also, the studies conducted are in lab settings and I do not if its efficacy is relatable in garden settings.

4. Aspirin Wards Off Insects

Aspirin water may modulate the immune response of the plants. The available studies are inadequate if they can ward off insects and pests from the tomato plants.

Tomato plants are constantly being attacked by several insects and pests. Many gardeners claim that aspirin wards off insects and pests.

Martha McBurney, a master gardener in charge of the vegetable garden at the University of Rhode Island used the aspirin water in the raised beds. The aspirin-treated plants were huge and insect-free. Martha recommends aspirin as a viable alternative to synthetic pesticides.

But, there is no clear scientific evidence to support this claim. The aspirin may not fight against the pests and remove them.

5. Aspirin Improves Seed Germination

There is a claim that aspirin water may improve germination. However, there are no scientific studies to validate the statement.

A diluted solution of aspirin may help with accelerated germination.

Martha of the University of Rhode island soaked aspirin water on the seeds of the tomato plants and sowed them in the ground. They observed 100% seed germination compared to other trial beds.

However, there is no valid scientific proof to support the findings of Martha.

Is Aspirin Good for Tomato Plants? – Conclusion

Overall, the aspirin solution spray may have certain effects on tomato plants. The available studies are insufficient to conclude. Also, we need more scientific studies to understand the dose required and the mechanism by which it helps with the growth of tomato plants.

How To Use Aspirin In The Tomato Garden

Aspirin may be dissolved in a gallon of water. It may be sprayed throughout the tomato plants. Alternatively, the seeds may be soaked in aspirin solution and then sowed for better results.

Many gardeners spray the tomato plants with a solution containing aspirin. Some prefer to soak the seeds in aspirin solution and then sow them.

You may dissolve 325mg of uncoated aspirin in one gallon of water. The rusted garden suggests adding a teaspoon of dish soap to a gallon of water that may help in sticking the solution to the tomato plants.

You may dissolve two 325mg of aspirin in a gallon of water for a drench. You may spray or drench the tomatoes every 14 days with the aspirin spray mix.

Many gardeners mention that this ratio works only for tomato plants. Also, don’t increase the amount of aspirin as it may be toxic to the tomato plants.

Check out this video to use aspirin to activate the natural defenses in tomato plants:


Is salicylic acid the same as aspirin?

No. The active ingredient in aspirin is acetylsalicylic acid. It produces salicylic acid and acetic acid when it is dissolved in water. Salicylic acid has many benefits.

Will aspirin harm the plants?

The aspirin may not be harmful to the plants if used in the proper dose. It may be sprayed early in the morning so that it may dry by the evening. If it is not used properly, it may cause brown spots in the leaves.


I hope this article has cleared if aspirin is beneficial for tomato plants.

If you have any queries, please contact me. Also, I am interested to hear about your experience in using aspirin for tomato plants.

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