Skip to Content

Baking Soda for Plants – 20 Clever Uses for Baking Soda in the Garden

Do you use baking soda for plants? Baking soda in the garden can be used in lots of different ways.

Many of us think of baking soda in conjunction with various  indoor “green cleaning” techniques.  It has so many uses in the house, that it makes sense that it will work outdoors too.

We all know that we should keep a carton of baking soda in the fridge to take away odors. but there are so many other uses for it too, even in the garden!

From tool cleaning to acting as a fungicide, baking soda is every gardener’s friend.

Plant with dirt, hand trowel and baking soda on a spoon.

Anyone with kids has likely seen baking soda being used used in science classrooms. The scientific term for it is sodium bicarbonate.

This product has specific chemical properties that make it a useful tool in the garden, too.

If you are a homemaker who likes to use kitchen hacks, you’ll likely have a box of baking soda in the back of your fridge to absorb odors and keep your fridge smelling great.

Not only does it curb unwanted smells, it’s useful as a cleaner, as well. I included baking soda in my list of ways for removing cooking oil stains from clothing. Be sure to check the article out!Collage with garden tools, flowers, soil, and baking soda and words reading using baking soda in your garden

Baking soda is not just for absorbing fridge odors. There are lots of ways to use it in the garden. Head to the Gardening Cook to find 30 creative ideas. #bakingsoda #weedkiller #fungicide Click To Tweet

What Is baking soda?

Baking soda is a simple, natural product that is made of sodium bicarbonate, which is highly alkaline. When it is combined with something acidic, it will produce carbon dioxide gas.  

In cooking, this action causes the ingredients to rise which is why it is used for making bread.Box of baking soda with some spilled sodium bicarbonate

The baking soda is also known to be a good all around cleanser with mildly abrasive properties. It is great at absorbing odors. There are many ways that baking soda can be put to use in the home.

Even though baking soda is made of just one ingredient – sodium bicarbonate, that ingredient is a combination of carbon, sodium, hydrogen and oxygen. (57.1 percent sodium, 27.4 percent oxygen, 14.3 percent carbon and 1.2 percent hydrogen.)

The compound is a white powder that sometimes forms lumps. It is odorless and has a bitter, but slightly salty taste. It is solid at room temperature, and is able to be dissolved in water.

Uses for baking soda

The properties of the baking soda lend themselves to many uses around the home. 

One only has to look on line and ask what baking soda is good for to come up with all sorts of ways:

  • Baking soda deodorizes and absorbs odors.
  • It acts as a natural cleaner.
  • Many people use baking soda for health reasons.
  • It is often used for personal hygiene and care.
  • Baking soda can be used as a fire extinguisher!
  • USe baking soda to soak fruit and veggies.

Wheel barrow in the garden with box of baking soda and words reading "using baking soda in the garden."

Baking soda for plants – clever ways to use baking soda in the garden

Not only can baking soda be used in cleaning and other ways in the home, it there are also many baking soda garden uses, as well. Here are some ways to use baking soda effectively in your garden.

Box of baking soda with vegetables with words 10 ways to use baking soda in the garden.

These are some of best uses for baking soda in the garden that we will discuss in the article below:

  • Treating fungal and other diseases
  • As a natural outdoor cleaner
  • Deodorizing garden tools
  • To make weed killers
  • Testing soil for pH
  • Insect repellents
  • Reviving plants and flowers
  • Treating sunburn
  • Precautions about use of baking soda

Each of these techniques can be used in several ways.  Read on for more details.

Baking soda on plants for fungus

There are several plant diseases that attack both flowers and vegetable plants.  If this happens, use baking soda on plants for fungus. Some remedies use baking soda in combination with other ingredients and sometimes it is used on its own.

Let’s see what happens when we use it as a natural fungicide.

Using baking soda for rose black spot fungus

The compounds in baking soda are thought to have the ability to prevent fungal spore flare ups on roses. However, it is likely that baking soda will not kill the spores themselves.

To use sodium bicarbonate for plants as a fungicide, mix 4 teaspoons of baking soda with a gallon of water. Baking soda diminishes the effects of fungal diseases on common ornamental and vegetable plants.

Use the mixture on roses (for black spot fungus) and also on grapes and vines when the fruit first begins to appear.  Black spots on rose leaves.

The solution works on black spot by helping to change the pH level on the leaves which makes it harder for the fungus to infect the plants.

Try this solution if  you have late blight causing black spots on tomato plants, too.

Use baking soda to treat powdery mildew

Baking soda has long been used to treat powdery mildew on plants. It will act more as a preventative than a solution once the plant has been affected. Powdery Mildew on pumpkin leaves.

Powdery mildew can cause major problems in gardens with high humidity. It affects many types of plants.  Zinnias, impatiens, squash and cucumbers are often badly affected. 

To use baking soda for powdery mildew, mix  the following ingredients:

  • 1 tablespoon of baking soda
  • 1 gallon of water,
  • 1 tablespoon of vegetable oil
  • 1 tablespoon of dish washing liquid.

Mix well and put into a spray bottle.  Use weekly. It is best to use it when the weather is not too sunny.

As a fungicide, baking soda works by disrupting the ion balance in fungal cells. One does need to be careful using it around plants in case the leaves burn.

Make sure that the solution is very well diluted before use.

Baking soda mixed with Neem oil, onion and garlic is also considered by some gardeners as a way to get rid of squash bugs.

Baking soda as a fungal spray for tomato plants

Tomato plants are prone to all sorts of fungal diseases. Leaf spot and early blight are a couple of common ones.  Mix baking soda with vegetable oil to make an organic tomato spray to help fight tomato fungal disease.

It also works on powdery mildew on tomatoes. Baking soda and tomato plants are a great match!

To make the spray, combine these ingredients:

  • 1 gallon of water
  • 1 heaping tablespoon of baking soda
  • 1 teaspoon of vegetable oil
  • 1/2 teaspoons of castile soap

Mix well and pour into a spray bottle. The vegetable oil will help the spray adhere to the leaves of your tomato plant. 

Spray this solution on the foliage of tomato plants until the fungal disease disappears.Tomato plant with a fungal disease

Be sure to test this on one or two leaves first and wait 48 hours before spraying your whole plant. The spray changes the pH level of the tomato plant and makes it harder for the fungus to take hold.

Using baking soda as a garden cleaner

Baking soda has long been used for general cleaning purposes. It absorbs odors and can be used alone or with other products as a cleaner in the garden and outside the home.

Baking soda is mildly alkaline which can cause dirt and grease to dissolve easily in water so that you can remove it effectively. Here are a few of my favorite ways to use it as a cleaner in the garden.

Baking soda to freshen garden recycle bins

I use large garden recycling bins to hold my yard waste for our trash pick up day. The city collects it and turns it into mulch.

The bins can turn pretty smelly after a week especially if the weeds that are put into the bins are moist. Gray and green waste bins on wheels.

A thick layer of baking soda in the bottom of the bins goes a long way towards getting rid of the odors in garden bins and my normal garbage bins as well.

Make a baking soda hand cleaner/odor absorber

If you love to garden, you know how grimy and smelly your hands can get, even if y0u wear garden gloves.

Clean your hands in warm soapy water and then rub baking soda on them after a day in the garden. Rinse well.

The baking soda will help to absorb the odors. Use it indoors, as well, to get rid of kitchen odors on your hands.

Dirty garden hands with fingers spread on grass.

Baking soda to clean garden furniture

Moisture and UV sunlight rays can make resin or wood garden furniture look drab and dingy over the course of the summer. Use baking soda to breath new life into your outdoor furniture.

Mix a half cup of baking soda with a tablespoon of dish washing soap and a gallon of warm water. It will clean your garden furniture so that it looks like new!

You can also use it on large plastic garden planters to clean them up, as well.White wood garden furniture with flower pots

For really dirty outdoor items, make a mix of baking soda and castile soap into a paste and use it to clean the furniture. Don’t use baking soda on metal furniture, since it can cause corrosion.

Cleaning clay pots with baking soda

Get rid of stubborn salt marks on clay pots by making a paste of baking soda and water. Add just enough water so that the mixture is the consistency of hand lotion. Baking soda in garden uses - cleaning Dirty clay pots

Rub the solution on the salt marks and leave for 20 minutes and rinse. For more tips on cleaning clay pots, see this post.

Note on using baking soda for compost piles: I have seen other articles that suggests using baking soda to take away odors from a compost pile. 

Properly done, with the proper amount of browns and greens, a compost piles should not be full of odor.

Be very careful about using baking soda anywhere near or in your compost pile. The compounds in the baking soda can essentially break down the pile and make composting much slower.

Cleaning your potting bench with baking soda

Soil and used plant pots can transfer diseases from one plant to another. Many people do a lot of their work re-potting and planting on a potting bench. 

Over time this can have the potential to harbor disease.

Galvanized metal can, with trowel and garden shears on a potting bench.

Give the potting bench a good scrub down once a month. Combine four tablespoons of baking soda with a quart of warm water. 

Scrub down the top of the potting bench and then give it a good rinse.

Clean a bird bath with baking soda

Baking soda is a very effective cleaning tool indoors and can also be used in the bird bath.  It won’t harm birds and other wildlife since there are no toxic chemicals in it.Bird bath near some garden plants.

To clean the birdbath, just make a mix of baking soda and castile soap into a paste and rub it onto the bird bath surface. Use a scrubbing brush to get rid of dirt, grime, and other debris.

It has a mildly abrasive effect to peel off stains, but won’t scratch surfaces.

Rinse the birdbath well  and fill it with clean water. There will be no harmful residue absorbed by birdbath so it’s safe for birds after cleaning.

Also see my articles on cleaning a cement birdbath and using copper and alka seltzer to clean a bird bath.

Use baking soda to make a plant fertilizer

Baking soda on its own can’t be used to fertilize plants, but you can use it with other products to make a good replacement for Miracle Gro garden fertilizer.Hand holding a flowering plant with words reading DIY miracle grow.

Just combine 1 tablespoon of epsom salt with a teaspoon of baking soda and a half teaspoon of household ammonia.  Put this mixture into a gallon of water and still well.

Use it once a month on your plants by mixing a 1/8 -1/4 of the concentrate with 4 cups of water in a watering can.

Check out this article for other natural plant fertilizers.

Use baking soda to get rid of weeds in the garden

Many people like to use natural ways to control weeds. Laying down newspaper to deter weeds, and using vinegar are tried and true methods. Baking soda also can be used to prevent weeds.

Baking soda is effective as a weed killer,  but it not permanent since it does not have a residual effect the way weed killing poisons do.

Baking soda weed killer – (preventer)

Use baking soda full strength on weed in cracks on a patio or walkway. This will kill any small weeds sprouted and prevent new ones from growing.weeds between cement paths

For weeds in garden beds, moisten the weeds with water from a hose. Measure out a teaspoon of baking soda and sprinkle it evenly right on top of the foliage of the entire weed, not just in the center the center.

Repeat for other weeds.

Will baking soda safe kill plants? In the same way that baking soda will kill and prevent weeds when used full strength, it will also kill plants. So be careful not to get the baking soda on desirable plants nearby or your lawn.

Baking soda as a crabgrass killer

Crabgrass can grow on lawns, in garden beds and in driveways. This weed killing trick works well for those times when crab grass is growing in your driveway.

Crab grass in a gravel driveway

To kill crabgrass, wet the weed and pour a heavy dusting of baking soda on it. The crab grass will die back in a few days.  Avoid the surrounding grass, since it will also kill the grass in your lawn.

Make your own soil testing kits

Soil pH is a measure of the acidity and alkalinity level present in soils. Soil pH levels range from 0 to 14, with 7 being neutral, below 7 acidic and above 7 alkaline. The ideal pH range for most plants is between 5.5 and 7.0.

There are soil testing kits available for purchase, but you can simply test your soil pH with baking soda and water. While the test is not totally accurate, it will give you some indication of your soil content and pH level.

You will need both vinegar and baking soda. Baking soda tests the soil for acidity and vinegar tests for alkalinity.

For both tests, take a sample of soil about 6 inches below the surface of the garden. Remove any sticks and place 1 cup of the soil in two clean cups.  Add enough water to turn the soil to mud.Baking soda soil test - garden soil with a trowel an spoon of baking soda.

To test for alkalinity, add 1/2 cup of vinegar to one of the cups and stir. If the soil fizzes, foams and bubbles, the soil is likely alkaline with a soil pH above 7.

To test for acidity, wet the soil and take a small amount of baking soda and sprinkle it onto soil. If the baking soda bubbles, your soil is acidic with a PH level under 7.

If neither soil fizzes, the pH of your soil is likely in the neutral range – 7.0. For more accurate test, contact your State Department of Agriculture. Many state departments will test your soil for free.

This post may contain affiliate links. I earn a small commission, at no extra cost to you if you purchase through an affiliate link.

Baking soda bug repellents

Natural pest control methods are far less expensive than the purchase of pesticides, and they much safer for your garden and wildlife. 

Many garden pests do not like the smell and taste of baking soda and will avoid it. This means that we can put it to good use to discourage pests in the garden.

Baking soda for garden pests

Ants, silverfish and cock roaches are just a few of the insects that don’t like baking soda. Sprinkle baking soda on the soil in your garden.  The insects that do not like it and will stay away. 

Kill slugs by putting it right on the pest. Be careful not to get it on the plants.

If you have ant mounds in your yard, dampen them with water and then sprinkle about 2 cups of baking soda on top of the mound.

Wait for a half hour or so and pour a cup of vinegar on the mound, as well. This combination will kill most ants.Ants, slugs, snail and garden pests.

You can also make a bait using half baking soda and half sugar to control ants and roaches. If you place this mixture around your plants (not too near to them) it will kill any slugs that might crawl through it.

When baking soda is eaten by insects, it releases carbon dioxide bubbles in their system that will kill the pests.

Killing cabbage worms

These little caterpillars don’t just feast on cabbage leaves, they also love to eat other brassicas such as broccoli, Brussels sprouts and kale in your vegetable garden, as well.

To kill cabbage worms, make a mixture of 50% white flour and 50% baking soda.

Cabbage worms on a leaf.

Photo credit Wikimedia Creative Commons Attribution-Share Alike 2.5 Generic license.

Put this mixture into a shaker container or a powder dispenser and dust the plants that are infested. The leaves of brassicas are thick and the mixture will not do damage to them but the caterpillars will eat it and soon die off.

Baking soda plant insect spray

Mix 3 tablespoons of baking soda, 2 tablespoons of canola oil and 2 tablespoons of liquid soap together. 

Pour the mixture into a bucket with 2 gallons of water. Add 2 tablespoons of vinegar. Stir well.Red spray bottle with words DIY plant spray.

Pour the mixture into a hand help sprayer. Mist the undersides and tops of plant leaves to control insects such as sap-sucking insects like aphids, mealybugs and scale.

Baking soda for plants

Is baking soda good for plants?

Anyone who gardens knows that flowers and other plants can sometimes feel the heat the way we do. Baking soda has a couple of uses to help in this regard.

Make cut flowers last longer

There are many household items that will help cut flowers to last longer in water. (Aspirin and vinegar are also good for this use.)

Hyacinths in a jar of water

Add a tablespoon of baking soda in two quarts of water. Change the solution every few days for best results and make a fresh cut on the stem end.

You’ll find that your cut flowers last longer than in just plain water.

Rejuvenate your rose bushes and other plants

Are your plants suffering from the heat?

Mix together these items:

  • 1 teaspoon of  baking soda
  • 1/2 teaspoon of  clear ammonia
  • 1 teaspoon Epsom salt
  • 1 gallon of water. 

Mix well and use on your plants. One gallon of the mixture will treat four rose bushes that have lost their luster.

It can be used on many types of plants. This coleus is the perfect candidate!

Coleus plant that is drooping from the summer heat.

This spray will work on plants that also are suffering a bit from the summer heat helping them to perk up and flower better.

Natural treatments for poison ivy

Anyone who spends a lot of time out in the garden has likely gotten a poison ivy rash. Have you heard the term “leaves of three, let them be?”

Sometimes, a gardener can find themselves in a patch of it unknowingly. Poison Ivy Vines

If this happens, one effective home remedy uses baking soda. To treat poison ivy, mix 1/2 cup of baking soda to some bath water and soak in it.

You can also make a paste by combining baking soda with apple cider vinegar or water and applying it to the rash to soothe the itch.

For other poison ivy, poison oak and poison sumac remedies, check out this post.

Treating sunburn with baking soda

Gardeners are often out in the sun for hours at a time and sunburn can take some of the pleasure out of the hobby, for sure. Even if you wear a sunhat and sunglasses, you may end up sore and burned.

If you have suffered from too much sun and have a sunburn that hurts, try treating it with baking soda.Sun hat and sun glasses

To enjoy the benefits of its sunburn relief, add ½ cup of baking soda to some warm bath water and soak in it for about thirty minutes.

Adding some baking soda to your favorite after sun lotion will allow you to continue the relief after the bath is finished.

Another way to enjoy the heat relief benefits is to mix baking soda with water into a paste and apply it directly to your skin.

Place one half-cup of baking soda in a bowl, and add cool water until the mixture is thin enough to spread on your skin.

Apply the mixture on the sunburn, and leave it on for around 15 minutes, then wash it off with cool water.

Things to consider when using baking soda for plants

Use baking soda home made remedies carefully. Although they have been used by many with success, using the product in careless ways could actually harm your plants.

Before you use a home made remedy for the first time in your garden, always test it on a small part of the plant first to make sure that it will not cause any harm.

If the mixtures seem too strong, dilute them and try again until you find the right strength. Each garden is different.

Be sure to protect any outdoor heating elements, wiring and metal from being exposure to baking soda, since this could cause corrosion of the metals.Fittonia plant, hand trowel, garden gloves and baking soda.

Also, don’t use home remedies on hot or really sunny days or this could lead to burning the foliage of the plants.

Don’t rely on home remedies as an excuse to be lax with garden maintenance. If you allow plants to become heavily infected with pests and fungal diseases, no amount of baking soda in the world will help them!

Have you found other uses of baking soda in the garden?  Please leave your tips in the comments section below. I’d love to add them to the article with a shout out to you!

Pin these tips for using baking soda for plants

Would you like to be reminded of these tips for using baking soda in the garden?  Pin this image to one of your gardening boards on Pinterest for easy access later.Three phones with pictures of garden items and words reading Baking soda for plants - uses in the garden.

Admin note: This post first appeared on the blog in June of 2013.

I have updated the post with all new photos, and additional information with tips for using baking soda in the garden, a project card for powdery mildew fungicide,  and a video for you to enjoy. I hope you find the updates useful.

Yield: 1 gallon

Baking Soda Fungicide for Powdery Mildew

Baking Soda Fungicide for Powdery Mildew

Baking soda has long been used to treat powdery mildew on plants. It will act more as a preventative than a solution once the plant has been affected. 

Prep Time 5 minutes
Total Time 5 minutes
Estimated Cost $5


  • 1 tablespoon of baking soda
  • 1 gallon of water
  • 1 tablespoon of vegetable oil
  • 1 tablespoon of dish washing liquid


  • Large container
  • Spray bottles


  1. Pour all of the ingredients into a large container.
  2. Mix well and then place into spray bottles.
  3. Be sure the solution is well diluted and shake before using.
  4. Use weekly on plants to prevent powdery mildew.
  5. Best used on overcast days rather than when it is sunny.
  6. Baking soda disrupts the ion balance in fungal cells to help prevent powdery mildew on plants.


Test on a few leaves before using on the whole plant. If the mixture is too strong, it can burn the leaves.

This fungicide is a preventative rather than a treatment for existing cases of powdery mildew.

Share on Social Media


Thursday 27th of July 2023

my lawn is totally full of crabgrass, how can i eliminate it without totally destroying a massive lawn, please,

Carol Speake

Friday 28th of July 2023

Hi Anne. There are chemical that will target Crabgrass (Scott's Spot Weed Control is one) but if the lawn is full of it, digging it up is the best solution.


Friday 23rd of September 2022

I made a mixture for my plant as follows.

Copper sulphate 30 GM's Baking soda 20 GM's Prophenophos 50 %ec Shampoo 18ml

All this together in 20litre and sprayed on my lemon trees after 1day lot of leaves are falling.

Pls help to quit from this problem

Golden Kajaba

Friday 5th of August 2022

well explanation no comments

bong carpio

Saturday 24th of April 2021

Is baking soda mixture like added with dishwashing liquid and vegie oil still favorable to add a pinch of ammonium sulphate..

Peggy Quattrocchi

Thursday 15th of April 2021

Hi Carol, Your gardening tips are great, thanks! I have a pear tree that I really love. Well, it developed pear rust on its leaves and now the tree looks like it is dying. The top branches are bare all the time. Will putting baking soda around the trunk of the tree help at all? I called an arborist for help and he wanted hundreds of dollars to come to take a look at my tree. Thank you for any advice you can give me. Peggy

Carol Speake

Saturday 17th of April 2021

HI Peggy. You will have better luck with someone locally. I don't diagnose any plants without being able to see the plant in person.

Disclosure of Material Connection: Some of the links in the post above are "affiliate links." This means if you click on the link and purchase the item, I will receive a small commission from the sale, but the price is the same for you. I am disclosing this in accordance with the Federal Trade Commission's 16 CFR, Part 255: "Guides Concerning the Use of Endorsements and Testimonials in Advertising."

Skip to Instructions