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! Baking soda in the garden is often used in various “green cleaning” techniques. It has so many uses in the house, so it makes sense that it would work outside too.
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.
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. Another box is probably in your pantry for use in baked goods.
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 causes the ingredients to rise which is why it is used for making bread.
The same concept also allows baking soda 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:
- To deodorize and absorb odors
- As a natural cleaner
- For health reasons
- For personal hygiene and care
- As a fire extinguisher!
- To soak fruit and veggies
Ways to Use Baking Soda in the Garden – Projects, Tests and Remedies
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.
These are some of the ways to use baking soda that we will discuss in the article below:
- Treating fungal and other diseases
- Natural outdoor cleaners
- Deodorizing Garden Tools
- Weed Killers
- Testing Soil for pH
- Insect repellents
- Reviving plants and flowers
- Treating sunburn
Each of these techniques can be used in several ways. Read on for more details.
Fungicides for various plant diseases.
There are several plant diseases that attack both flowers and vegetable plants which can be helped along by using baking soda, sometimes in combination with other ingredients and sometimes on its own. Let’s see what happens when we use it as a natural fungicide.
Rose black spot fungus
The compounds in baking soda seems to have the ability to prevent fungal spore flare ups, although it likely does not kill the spores themselves. To use baking soda as a fungicide, mix 4 tsp of baking soda with a gallon of water. Baking soda does seem to diminish 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.
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.
Treating 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 can cause major problems in gardens with high humidity. It affects many plants but zinnias, impatiens, squash and cucumbers are often badly affected. Mix 1 tbsp of baking soda, 1 gallon of water, 1 tbsp of vegetable oil and 1 tbsp of dish washing liquid. Mix and put in a sprayer. Use weekly. (try to use it when it 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.
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 it with vegetable oil to make an organic tomato spray to fight tomato fungal disease. It also works on powdery mildew on tomatoes.
To make the spray, combine a gallon of water with a tbsp of baking soda and 2 1/2 tbsp of vegetable oil in a spray bottle. (the vegetable oil will help the spray adhere to the leaves. Stir and add 1/2 tsp of castile soap. Spray this solution on the foliage of tomato plants until the fungal disease disappears.
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.
Baking Soda as a General Garden Grime Buster
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.
To Freshen Garden Recycle Bins
I use large garden recycling bins to hold my yard waste for trash pick up day. The city collects it and turns it into mulch. This can turn pretty smelly after a week especially if the weeds that are put into the bins are moist.
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.
Baking soda hand cleaner/odor absorber
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.
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.
For really dirty outdoor items, make a mix of baking soda and castile soap into a paste and use it to clean. Don’t use baking soda on metal furniture, since it can cause corrosion.
Cleaning Clay Pots
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.
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 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
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.
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
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 as there are no toxic chemicals in it.
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 and fill the birdbath with clean water. There will be no harmful residue absorbed by birdbath so it’s safe for birds after cleaning.
Use it 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 Grow fertilizer.
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.
Getting Rid of Weeds
Many people like to use natural ways to control weeds. Laying down newspaper and using vinegar are tried and true methods. Baking soda also can be used to prevent weeds.
The product is effective used this way but it not permanent, since it does not have a residual effect the way actual 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.
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, being careful not to get the baking soda on desirable plants or grass.
Crabgrass can grow on lawns, in garden beds and in driveways. This trick works well for when your drive way has crab grass in it.
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 if you can.)
Baking Soda for Soil Testing
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. One tests for acidity and one 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.
To test for alkalinity, add 1/2 cup 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 of these departments will test your soil for free.
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 so we can put it to good use in the garden 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. (don’t get it on the plants though.)
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.
You can also make a bait with 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 them, make a mixture of 50% white flour and 50% baking soda.
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.
Plant Insect Spray
Mix 3 tablespoons of baking soda, 2 tablespoons of canola oil and 2 tablespoons of oil soap together. Pour the mixture into a bucket with 2 gallons of water. Add 2 tablespoons of vinegar. Stir well.
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
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.
Help Cut Flowers Stay Fresh 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.)
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
Mix together one teaspoon of baking soda, 1/2 teaspoon of clear ammonia and one teaspoon Epsom salt in a gallon of water. One gallon will treat four rose bushes that have lost their luster.
This spray will work on other plants that also are suffering a bit from the summer heat helping them to perk up and flower better.
Baking Soda to treat Poison Ivy
Anyone who spends a lot of time out in the garden has likely gotten a poison ivy rash. Heard the term “leaves of three, let them be?” Sometimes, a gardener can find themselves in a patch of it unknowingly.
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.
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.
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 the 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 in the garden
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.
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!
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 and tips for using baking soda in the garden. I hope you find the updates useful.
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