Can Baking Soda Be Used as a Pesticide for Plants?

Pesticides are substances that drive away, control and kill pests in gardens. Natural pesticides are often favored because they pose no harm to plants, animals, and humans. Among the most popular natural pesticides are neem oil, garlic, and baking soda. 

Baking soda can be used as a pesticide for plants. It effectively prevents and kills fungal spores. It won’t harm the plant, the environment, and not even pets or children who may come into contact with it in your garden. You may use it for the treatment and prevention of fungal diseases.

We’ll talk about why baking soda is an excellent choice as a pesticide for your garden, how to use it, and what side effects you should expect. We’ll also discuss the different kinds of pesticides and what fungal disease looks like in plants before mentioning other uses of baking soda in the garden. Let’s get started!

Baking Soda as a Pesticide for Plants

Baking soda is an excellent pesticide for plants because it can help treat fungus by significantly reducing spores. You can use it to eliminate fungal diseases, like mildew, especially on vegetables and fruit-bearing plants. 

You may also use baking soda to reduce the risk of developing fungal diseases. Note that it is more effective as a prevention method than a way to eradicate fungal spores. 

Baking soda works by leaving an alkaline residue on your plants’ leaves and stems. An alkaline environment is not ideal for fungi spores to thrive. Airborne spores that get in contact with these leaves and stems won’t be able to survive.

If mildew or fungal disease is already present in the plant, the spores will eventually die because of the unsuitable environment created by baking soda. 

Make a Pesticide Spray

A bottle of baking soda pesticide spray will be a handy tool for preventing and treating fungal infections in your plants. You don’t need any special equipment or protective gear because it is safe to use. Baking soda poses no serious threats to plants, animals, or humans. 

Here is how to make your baking soda pesticide spray:

  1. Pour 1 gallon (3.8 L) of clean water into a jar.
  2. Add 1 teaspoon of baking soda.
  3. Add 1 teaspoon of dormant oil and ½ teaspoon of liquid soap. These act as emulsifiers to help stabilize the mixture and stick it to your plant’s leaves and stems.
  4. Stir until all elements are well-dispersed.
  5. Transfer some of the mixture into a spray bottle. Remember to shake the bottle before each use gently. 
  6. Seal the jar to protect the remaining mixture for later use. 
  7. Spray all over your plants’ leaves and stems. Don’t forget to spray on the undersides of leaves. 
  8. Repeat application until you have the fungal disease under control. Use at least once a week.

Some important pointers:

  • Apply this solution in the early mornings or late afternoons, when the sun is not at its peak. Timing your application out of peak sunlight reduces the risk of leaf burn. 
  • Remember not to use baking soda pesticide spray on your plants when you think it will rain. The mixture is water-soluble, and rain will just wash it away. 
  • Avoid using soaps that have bleach in them. These could harm your plants and may cause burns.

Possible Side Effects

Using baking soda as a pesticide for plants has its side effects. After all, too much of a good thing almost always has drawbacks.

Here are some of them:

  • May burn leaves: Baking soda may make your plants’ leaves develop yellow or brown patches at the tips. Do not overuse.
  • Repeated use may lead to the baking soda mixture seeping into the soil: Accumulating this natural pesticide will affect the soil’s nutrient content and may cause stunted growth in plants. Use this pesticide only once a week. 

Signs of Fungal Disease in Plants

Identifying fungi in your plants at the soonest possible time is essential to boost chances for a quick recovery. Fungal issues usually appear suddenly and are commonly persistent. Your plant’s best defense is a good pesticide that can drive fungi spores away.

Here are some signs that your plants may have a fungal disease:

  • Unusual spots or blotches on leaves and stems
  • Odd-colored growth
  • Stunted or oddly-shaped new leaves
  • Unexplained or sudden wilting
  • Rotting tissue
  • Formation of mold on stems and leaves
  • Powdery mildew

How Plants Acquire Fungal Disease

Fungal spores thrive by feeding on the plant’s energy, minerals, and nutrients. As these spores settle on your plant, you will notice signs of fungal disease on leaves and stems. As the fungal spores multiply and thrive, the plant starts to wither and die

These spores may have traveled to your plant via the wind. They quickly attach themselves to your plant’s leaves and stem to begin their parasitic activities.

On the other hand, some fungi live in the soil and invade your plant from the roots. They can block water absorption, so your plant will start to wilt and eventually die.

All About Pesticides

You can use pesticides to eliminate pests and diseases from your garden. We can opt for different kinds, depending on our preferences and needs. 

Some contain chemicals that boost pest and disease extermination effectiveness, while some contain only natural ingredients so as not to harm plants, animals, and humans. There are commercially-produced pesticides, and there are also some that we can make at home. 

Pesticides come in 5 main categories:

  • Herbicides destroy weeds, invasive plants, and other unwanted vegetation.
  • Disinfectants help prevent the spread of bacteria.
  • Compounds drive away and kill larger pests like rats and mice.
  • Insecticides repel, control, and kill insects and pests on plants.
  • Fungicides prevent the growth of molds and mildew.

Other Uses of Sodium Bicarbonate in the Garden

Baking soda is one of the most useful and versatile ingredients we can find in the kitchen. We know it as a great cleaning agent and a valuable component for certain beauty routines. Surprisingly, it offers many benefits in the garden as well.

Here are some other uses of baking soda for your plants:

Keeps Insects and Pests Away

Baking soda can also act as an insecticide, as it deters insects and pests. Simply sprinkle a handful on the soil around your plants using a flour sifter.

Baking soda deters pests such as ants, slugs, and roaches and might even kill them by releasing carbon dioxide into their systems when consumed. On the other hand, beneficial insects, like ladybugs, are undisturbed by it. 

You can also use baking soda as a maintenance insecticide for your plants. It’s safe enough to use regularly to keep pests and unwanted insects at bay. Combine it with neem oil for a synergistic effect.

Neem oil is a proven safe and effective agent in preventing and killing pests.

Here is what you can do to make your own baking soda insecticide spray:

  1. Fill a jar with 1 gallon (3.8 L) of water.
  2. Add 2 tablespoons of neem oil, 2 teaspoons of baking soda, and 1 tablespoon of liquid soap. 
  3. Mix until all the elements are well distributed. 
  4. Transfer some of the mixture into a spray bottle. 
  5. Spray all over your plants. 
  6. Use weekly and only in the early mornings or late afternoons (to prevent foliar burn).

Kills Invasive Grass and Weeds

Certain types of grass, like crabgrass, can proliferate so that they can quickly take over your whole garden. Weeds can also exhibit unrestrained growth habits and can eventually suffocate your plants. 

Baking soda can come to the rescue. Hose down the patch of grass or weeds you would like to get rid of, then sprinkle some baking soda over the area. The unwanted grass and weeds will die in just a few days

Makes Tomatoes Taste Better

Surprisingly, baking soda can make tomatoes juicier and taste sweeter. The acid level in the soil is the contributing factor, and this is where baking soda comes into play.

Sprinkle a small amount around your tomato plants to reduce the soil’s acidity level. Lower acidity levels make tomatoes taste sweeter

Cleans Bird Baths, Bird Cages, Pet Crates, and Other Outdoor Facilities

We all know about baking soda’s prowess in the cleaning department, so why not put it to good use out in our gardens?

Using baking soda is a great way to ensure that our clean areas will be safe for our plants, pets, and other garden friends. Simply scrub dirty spots with a damp sponge and baking soda, then rinse with water. 

Neutralizes Odors

Baking soda is excellent for getting rid of foul odors. You can use it for your compost bins, pet crates, bird cages, or anywhere in your garden that may give off unpleasant smells.

Sprinkle a little bit of baking soda on and around these areas to eliminate the odors. 

Makes Cut Flowers Last Longer

Picking flowers is bittersweet. You will enjoy a flower’s beauty and fragrance from the comfort of your home, but it also means that the flower will soon die. Enjoy it for longer by mixing a teaspoon of baking soda with the water in its vase. 

Freshens up Those Dirty Hands

An afternoon of working in the garden is a surefire way of ending the day with dirty, grimy hands. Sometimes, washing with soap and water isn’t enough to remove certain smells. Baking soda can help!

Pour some into your hand, get it wet, and scrub. Your hands will smell fresh again after you rinse them with water. 

Final Thoughts

Baking soda is a safe, effective, and reliable pesticide for plants that you can regularly use to reduce your plants’ risk of any fungal diseases. You can also use it to treat fungal spores in your plants. Baking soda is a handy garden ally that offers many other uses and benefits.

Alexander Picot

Alexander Picot is the founder of and its lead content writer. He created the website in 2022 as a resource for horticulture lovers and beginners alike, compiling all the gardening tips he discovered over the years. Alex has a passion for caring for plants, turning backyards into feel-good places, and sharing his knowledge with the rest of the world.

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