Tomatoes are easy-to-grow plants, but they’re prone to pests and diseases that give us gardeners quite the headache. Luckily, kitchen cabinet staples like baking soda can help prevent these tomato plant problems!
Learn how to use baking soda effectively and apply it in your garden to keep your tomato plants healthy.
How do you use baking soda on tomato plants?
To keep tomato plants healthy, use baking soda as a natural pest repellent, fungicide, fertilizer, and powdery mildew controller.
Read on to understand baking soda uses that work on tomato plants and a step-by-step guide on how to do them yourselves.
1. As a Natural Pest Repellent
Pests like aphids, snails, worms, and slugs love feasting on tomato plants. And a natural way to get rid of them is, of course, by using baking soda.
As an abrasive powder, baking soda essentially absorbs these pests and insects’ exoskeletons, causing dehydration.
If you have snails and slugs, you can place the baking soda in traps around the plant to bait them. To seal the deal, you can even sprinkle baking soda on the snails and slugs once they bite the trap.
Aphids are also tiny pests that love the sugary sap from tomato plants. They’ll defoliate the plant when left unchecked, and no one wants that.
An easy way to get rid of aphids is to sprinkle baking soda, creating a barrier at the base so they cannot go near the tomato plant. From that point, aphids will get irritated by baking soda, preventing them from feeding on the plant.
However, don’t use too much baking soda because it might kill these pests and the tomato plant itself. As the saying goes, in everything, practice moderation.
Here’s how to create and use your own baking soda repellent:
| Difficulty | Easy ●○○○○ |
| Duration | 15 to 30 minutes |
| Things You Need | • Spray bottle • 10 drops of basil essential oil • 1 teaspoon of baking soda • 1 cup of water |
| How To Do: 1. Mix one cup of water and one teaspoon of baking soda in a spray bottle. 2. Add ten drops of basil essential oil to the solution and shake the container well. 3. Spray the baking soda solution over your tomato plants. 4. Re-apply the baking soda solution after a rainstorm or watering. |
2. As a Natural Fungicide
Tomatoes are vulnerable to bacterial and fungal diseases like early and late blight.
For instance, early blight manifests through small brown spots with yellow halos on the bottom leaves, eventually killing all the plant leaves.
Late blight, however, has no cure and marks the surefire death of your tomato plant. Once you see dark lesions on the edges of the leaves and white mold on the undersides, that’s the beginning of late blight.
Expect late blight to spread through the plant’s stems and fruits before killing the plant entirely.
Fortunately, you can prevent your tomato plant from a tomato blight infection through baking soda.
Baking soda has alkaline properties, making the plant’s surface unsuitable for blight fungi. It disrupts the fungal cells’ balance, preventing them from spreading.
By spraying baking soda, you’ll prevent any blight from penetrating and spreading on your tomato plant.
But to emphasize, using baking soda as a fungicide should be used as a preventive measure. Once the infestation starts, sadly, there’s nothing baking soda can do to help.
Here’s how to use baking soda for tomato blight prevention.
| Difficulty | Easy ●○○○○ |
| Duration | 15 to 30 minutes |
| Things You Need | Spray bottle Few drops of dish soap 1 teaspoon of baking soda 1 quart of water |
| How To Do: 1. Mix one teaspoon of baking soda and one quart of water in a spray bottle. 2. Add 2 to 3 drops of dish soap to the solution and shake the container well. 3. Spray the baking soda solution on the tomato plant’s leaves and stems every 7 to 10 days. |
3. As a Natural Fertilizer
Although too much baking soda will kill the tomato plant, there’s actually a workaround. Mix baking soda with Epsom salt so you can use it as a natural fertilizer for tomatoes!
Baking soda helps eliminate fungal spores, while Epsom salt encourages tomato plants to flower.
Here’s how to turn baking soda and Epsom salt into a natural fertilizer.
| Difficulty | Easy ●○○○○ |
| Duration | 15 to 30 minutes |
| Things You Need | • Large container1 teaspoon of baking soda • 1 teaspoon of Epsom salt • Half teaspoon of ammonia • 1 gallon of water |
| How To Do: 1. Mix one gallon of water, half teaspoon of ammonia, one teaspoon of baking soda and Epsom salt in a large container. 2. Allow the solution to sit for 30 minutes so the salt completely dissolves in the water. 3. Store the solution in a cool dark area. You can now use it as plant feed once a month. 4. Pro tip: You can also use eggshells to add calcium, coffee grounds, and banana peels for additional nutrients to your tomato plants. |
4. As a Powdery Mildew Controller
Powdery mildew is another fungal disease you wouldn’t want your tomato plant to have.
Although the grayish-white powder gives the plant a snowy vibe, don’t be fooled because powdery mildew will prevent your tomato plant from conducting photosynthesis, and fruiting, and even cause defoliation.
Baking soda creates an alkaline environment which powdery mildew gravely dislikes.
Here’s how to use baking soda to prevent powdery mildew.
| Difficulty | Easy ●○○○○ |
| Duration | 15 to 30 minutes |
| Things You Need | • 1 tablespoon of baking soda • 1 gallon of water • Half teaspoon of non-detergent dishwashing liquid • Water jug or bottle • Sprayer |
| How To Do: 1. Mix one tablespoon of baking soda, half a teaspoon of dishwashing liquid, and one gallon of water in a water jug or bottle. 2. Transfer the solution to a sprayer. Spray the baking soda solution on tomatoes, preferably during cloudy days, to prevent the burning of leaves and sunscald. 3. Make sure the solution is also applied to the tomato stems and the undersides of the leaves. |
Fortunately, baking soda can also be used to treat and eliminate powdery mildew.
Here’s how to treat this fungal disease if your plant already suffers from powdery mildew.
| Difficulty | Easy ●○○○○ |
| Duration | 15 to 30 minutes |
| Things You Need | • Baking soda • 2 gallons of water • Spray bottle • Vegetable oil • Murphy’s oil soap • Liquid soap |
| How To Do: 1. Baking Soda and Vegetable Oil Solution: Mix one tablespoon of baking soda, one tablespoon of vegetable oil, and one gallon of water in a container. Add one teaspoon of liquid soap and shake the container until well mixed. 2. Baking Soda and Murphy’s Oil Solution: Combine two tablespoons of Murphy’s Oil and four tablespoons of baking soda with one gallon of water. Shake the container well. 3. Spray these two solutions alternately every week to treat powdery mildew on tomato plants. This way, the fungi will not develop resistance against the two solutions. |
FAQs on Using Baking Soda on Tomato Plants
Baking soda is a safe ingredient in keeping your tomato plants healthy, as long as you use them in moderation. Baking soda becomes a natural pest repellent, fungicide, and pest repellent for tomato plants.
Spray baking soda solution on your tomato plant every 7 to 10 days to prevent the surface of the plant, especially the leaves, from becoming a breeding ground for bacterial and fungal diseases.
Baking soda does not treat blossom end rot. The better option is to add lime, eggshells, or other sources rich in calcium carbonate in the soil to treat the problem of lack of calcium causing blossom end rot.
Baking soda changes the pH level of the plant’s foliage, making it inhabitable for fungal spores. This prevents the tomato plant from contracting fungal diseases like early or late blight.
