Should You Use Baking Soda For Tomato Plants?

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Quick Answer: Should You Use Baking Soda For Tomato Plants?

The household ingredient baking soda is considered safe in moderate amounts. It may prevent the bloom and release of fungal spores. The baking soda spray may reduce the incidence of powdery mildew and blight on tomato plants. It may kill garden pests and weeds. However, there is insufficient evidence to support the claims that baking soda induces flowering and makes tomatoes sweeter.

This detailed & fact-based guide will provide you answer if baking soda is beneficial for tomato plants.

I have compiled all the speculations about using baking soda for tomato plants and incorporated the supportive science based on research and my personal experience.

Scroll down for more information!

Should You Use Baking Soda For Tomato Plants?

Baking soda is a common household ingredient that is gaining popularity for several tomato problems. It is considered a safer alternative to traditional fungicides.

There are many gardening hacks for tomato plants that are going viral on the internet.

It may be eggshells, Epsom salt, aspirin, neem oil, used coffee grounds, and many more. 

One such hack suggested by many gardeners is baking soda for a myriad of tomato problems. Baking soda or sodium bicarbonate is registered with EPA as a safer fungicide.

Claims of Using Baking Soda For Tomato Plants – Myth or Truth?

There are many claims about using baking soda for tomato plants. In this subsection, let us discuss if these claims are backed by science or are just myths.

1. Can Baking Soda Prevent Fungal Diseases

Yes, baking soda prevents fungal diseases. Baking soda makes the surfaces of the plants more alkaline, which is not conducive to the growth of fungi. It thereby helps in preventing fungal diseases and the spread of the fungal infection to the whole plant.

Tomato plants are susceptible to different fungal diseases, including tomato blights, spots, and powdery mildew.

These diseases may spread and kill the whole tomato plant.

Powdery mildew is a fungal disease forming white-gray powder on tomato leaves.

Tomato blight causes severe defoliation on the leaves and stems of the tomato plants.

Baking soda is claimed to kill fungi that affect tomato plants and treat fungal diseases.

Dr. Martin Draper, a plant pathologist through USDA, suggests spraying the tomato plants with a heaping tablespoon of baking soda.

As baking soda creates an alkaline environment, it is unsuitable for the fungus to grow and release the spores.

Dr. Leonard Perry of the University of Vermont demonstrates that baking soda when combined with horticultural oil is effective on powdery mildew of the tomato plants.

So, it may be efficient in preventing the spread of fungal infection in tomato plants. But, if the infection has already set in, baking soda may not be efficient in curing the fungal disease.

Most of the studies are performed in lab settings. I don’t know if it can be relatable to outdoor settings.

2. Does Baking Soda Kills Snails And Slugs?

Yes, Baking soda may be sprinkled around the tomato plants. It may kill the snails and slugs that come in contact with baking soda.

Tomato plants are often troubled by several garden pests, including snails and slugs.

Baking soda may kill snails and slugs. It may dehydrate the snail through the process of osmosis. It makes these creatures dehydrated and finally kills them.

Many gardeners feel that they need a larger amount of baking soda to kill snails. Be cautious as more baking soda may be harmful to tomato plants. 

Personally, I feel it is cruel to kill the snails and slugs using baking soda just like salt. I do not use it for snails.

3. Does Baking Soda Makes Tomatoes Sweeter

Baking soda is claimed to make tomatoes sweeter by decreasing the acid levels in the soil. However, there are no scientific studies to support the claim.

Not all tomato varieties have the same level of sweetness. It may depend on temperature, sunlight, soil, and the amount of rain.

Some gardeners suggest sprinkling baking soda around the tomato plants to make them sweeter.

The theory is that baking soda may lower the acid levels in the soil and make the tomatoes sweeter and less tart.  

However, it did not work for me.

Also, no scientific studies are available backing this claim. And the amount of baking soda needed to alter the soil pH may be high and detrimental to tomato plants.

4. Baking Soda Kills Weeds

Yes, Baking soda may kill weeds by dehydrating them. But, it may also be harmful to the neighboring tomato plants as baking soda is nonselective.

There is a popular claim that dumping a handful of baking soda over weeds kills it. It forces the foliage of the weeds to dry off by drawing the water from the plant cells.

It works like salt.

But one drawback is that baking soda is non-selective. So, it may be phytotoxic to desirable tomato plants due to high sodium levels.

So, I wouldn’t recommend baking soda to kill weeds as it may be harmful to tomato plants.

5. Baking Soda Increases Flowering

There is popular speculation that baking soda increases flowering by enhancing sodium content. But the available scientific proof does not support the claim.

Some gardeners claim that sprinkling the water dissolved in baking soda on the tomato plants may encourage flowering. It may work if the plants have sodium deficiencies.

Sodium is an essential micronutrient required for the growth of plants.

There is no proof showing that adding sodium to tomato plants will increase their flowering.

Also, too much sodium may be toxic to the plants.

Check out this video on how to use baking soda for tomato plants:


Is baking soda harmful to tomato plants?

The diluted baking soda solution may not be harmful to tomato plants. In contrast, if the concentration of the baking soda is high, it may leave abrasions on the leaves of the tomato plants and discoloration of some fruits.

Can baking soda be used with neem oil?

Yes. Neem oil has fungicidal properties against several fungi. Baking soda when used with neem oil can be effective against fungal diseases, including powdery mildew.


If you have had some queries about using baking soda for tomato plants, I hope this guide has provided you with the answers.

Share your own experience in using baking soda for tomato plants. Would love to hear.

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