Sodium bicarbonate, more commonly known as baking soda, is a salt.
Most people have baking soda in their pantries, as it is commonly used for removing stains and is an ingredient for creating inexpensive household cleaning products.
If you have pesky weeds or unwanted grasses growing in the cracks of your sidewalk or patio, you may be seeking an alternative to harmful chemical herbicides.
So, will baking soda kill grass and weeds?
Baking soda is poisonous to plants, and it will slow the growth and prevent the germination of grass and weed seeds, eventually killing them. Since baking soda is a salt, it absorbs water from plant cells and makes it impossible for them to maintain healthy moisture levels needed for survival.
Bicarbonate soda is as effective as harsh chemical weed killers, but it will harm healthy lawn grass without careful application.
Only apply baking soda to plants you intend to kill to avoid damaging effects on your lawn or garden.
Read on to learn how to use baking soda to get weeds under control without damaging your lawn or flower beds.
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The Effects of Baking Soda on Different Grass Types
No plant life is immune to being killed by baking soda.
However, some lawn grass types are more resistant to the effects of sodium bicarbonate than others.
Understanding the effects of baking soda on different grass varieties is crucial if you plan to use the baking soda method as a weed remover.
Further Reading: Ways to kill weeds for good
Bermuda grass is one of the tougher grasses to kill with baking soda but it is not completely immune.
For the best results, mix a sodium bicarbonate paste to spot treat weeds and avoid getting any baking soda residue on the surrounding Bermuda grass.
It may take several applications to be effective if you would like to remove unwanted Bermuda grass from your lawn.
St. Augustine grass is not as resistant to the effects of baking soda as Bermuda grass.
Some advise against using sodium bicarbonate for weed removal on St. Augustine, while others have used it with great success.
Use extreme caution if you apply a baking soda solution to patches of weeds on a St. Augustine lawn.
Hardy crabgrass weeds are notorious for being challenging to remove from lawns.
Fortunately, crabgrass is highly susceptible to the effects of baking soda.
Mix a paste consisting of one part baking soda to one part water and apply it carefully to the crabgrass.
You may want to cover healthy lawn grass near the application site for added protection.
This method works best in sunny weather, and you will begin to see black crabgrass spots within a few days.
Baking soda works well to remove stubborn crabgrass from your lawn permanently.
Torpedo grass is commonly found in coastal areas of the Southern United States, and it thrives on marshy shores, canals, and poorly-drained soil.
This invasive weed is resistant to most selective herbicides and can survive frequent mowing, changes in pH, and root damage.
The major weakness of torpedo grass is its constant need for water to thrive.
Baking soda effectively eradicates torpedo grass because it inhibits the plant’s ability to retain moisture.
Applying a baking soda solution to torpedo grass in the spring while the plant is actively growing is best.
Zoysia grass is one of the least resilient grasses against the effects of baking soda.
The recovery rate of Zoysia after sodium bicarbonate application is much lower than in St. Augustine.
Some varieties of Zoysia grass may not even grow back after being exposed to baking soda.
If you have a Zoysia lawn, applying baking soda anywhere near it is not recommended.
How To Use Baking Soda for Weed Control
There are several ways to apply baking soda for effective weed control.
The method you choose depends primarily on where the weeds are located.
For the best results, apply sodium bicarbonate in the morning while the plants and soil are still wet from dew.
Daytime temperatures above 85° degrees Fahrenheit (29° C) will also speed up the process.
Make a Spray
This method works best for weedy areas without a lot of grass or flowering plants since the droplets may travel through the wind.
If the weeds or soil are dry, water the area first, so the baking soda sticks better to plant leaves and the ground.
Measure equal parts baking soda and water, and add to a spray bottle.
You may add one tablespoon of vegetable or olive oil as a surfactant to help the mixture stick to the weeds.
The baking soda solution will rise in the bottle, so allow it to settle for a minute or two.
Gently shake the spray bottle to thoroughly mix the solution, then spray the undesired weeds.
Brown patches of weeds will be visible within a few days to let you know the mixture is working.
You may need to repeat this process a few times to eliminate weeds.
Use It Dry
Dry baking soda is useful for more selective weed removal in small areas like flower beds.
Carefully sprinkle one tablespoon of baking soda on the leaves, stems, and roots of the weed or grass you would like to eliminate.
Avoid spilling the dry sodium bicarbonate on nearby flowering plants.
Cover surrounding areas to protect your flowers or grass from damage.
The weeds will turn brown within a few days and then die off.
Like most natural products, it may take more than one application of baking soda to completely remove the tougher grasses or weeds.
You may lightly dampen the weeds to help the sodium bicarbonate stick to the leaves better.
Once the weeds are dead, water the ground to remove any leftover residue.
Baking soda lowers the acidity levels in healthy soil and needs to be restored before planting anything in the treated area.
Combine with Vinegar
For particularly stubborn patches of weeds, combine the baking soda with vinegar to make a paste.
Vinegar contains acetic acid, which works much like baking soda to remove moisture from a plant.
Pickling vinegar has a higher acetic acid concentration than a typical bottle of household vinegar, but both kinds are acceptable.
You may want to avoid the concentrated acetic acid vinegar found in hardware stores due to the risk of burning your skin.
Water the target area first so the solution sticks to the unwanted grasses or weeds.
Mix two parts baking soda with one part vinegar in a large bowl.
If you prefer a spray, combine two cups of baking soda with two cups of water and one tablespoon of cooking oil in a sprayer.
Once the mixture settles, apply the paste or spray to the unwanted patch of weeds.
The weeds will turn brown and die within a few days.
How To Neutralize Baking Soda
If you accidentally spill baking soda onto your healthy grass or flowers, you need to neutralize it immediately with water.
Either turn on your sprinkler system or use a garden hose to add at least 1″ inch of water to the affected area.
The water will wash away the sodium bicarbonate and dilute it before it causes any damage to your desirable plants or grasses.