Killing Crabgrass With Baking Soda (Explained + Precautions)

During growing seasons, gardeners go through the hassle of dealing with stubborn and rapidly growing weeds, including crabgrass. Weeds are the bane of most gardeners because getting rid of them takes time and effort. While regular weeding may reduce the weed population, crabgrass is a stubborn lot.

Because weed killers have many harmful effects, people look for safer alternatives to crabgrass removal. One alternative solution is baking soda, an effective home remedy for crabgrass control. 

Does killing crabgrass with baking soda work? Which solutions can you mix with baking soda to kill crabgrass? Keep reading to learn about baking soda and how to use it.

The Many Uses of Baking Soda

baking soda used to kill crabgrass

Baking soda, also known as sodium bicarbonate, is commonly used as a baking ingredient for making bread, cookies, muffins, etc. Besides cooking, baking soda has numerous uses, from teeth whitening to cleaning agents; little wonder it’s touted as a household staple. 

People also use baking soda as a pesticide (PDF) or weed killer in gardens to keep pests and weeds at bay. Some weeds this white solid substance acts on include crabgrass, turfgrass, etc.

Can Baking Soda Kill Crabgrass?

Yes, it can kill crabgrass. All thanks to its phytotoxic properties, which slow the germination of seeds and growth of plants. This also leads to damaging effects on leaves, causing the plant to lose moisture quickly. 

Does Baking Soda Kill Crabgrass Permanently?

Yes, baking soda dries and kills crabgrass permanently by targeting crabgrass at its central root while drying it up. It’s best to attack the weeds early because they’re easier to control than mature ones.

While a single application works, you might need to spray baking soda multiple times to eliminate crabgrass permanently. As a contact herbicide, you’ll soon see results within hours of applying baking soda. Baking soda is an efficient weed killer, and you’ll need to apply it carefully, so you don’t harm other plants. 

How to Kill Crabgrass With Baking Soda

Typically, baking soda removes moisture from the leaves, stems, and roots, resulting in tissue damage and eventually the death of crabgrass. Below are steps to killing crabgrass with baking soda.

1.) Wet the Crabgrass

Water the infested area using a sprinkler or garden hose. Due to the wetness, the baking soda will stick quickly to the plant surface for maximum effect. However, you might not need to wet the crabgrass if you’re applying baking soda in the morning because the plant may get moistened by dew. 

2.) Cover Surrounding Plants

As a non-elective crabgrass killer, baking soda can potentially kill other neighboring plants. Therefore, before applying the chemical on crabgrass, cover the plants surrounding the crabgrass with cardboard or any other material that will act as a protective covering.

3.) Apply a Good Dose of Baking Soda

After covering the surrounding plants, sprinkle a small amount of baking soda on the affected parts. You might need to apply the substance multiple times depending on the level of crabgrass infestation.

4.) Allow Baking Soda to Sit

Once you apply baking soda, let it stay for some hours to increase absorption by the plant. You’ll eventually see the leaves white and wilting within a few hours. Over time, the leaves may undergo discoloration, appearing black or brown. In addition, the crabgrass may experience stunted growth.

5.) Discard Dead Crabgrass

To completely remove crabgrass from your lawn, pull by hand or use a garden shovel or weed remover. If you don’t remove crabgrass properly, the plant will soon start sprouting again.

6.) Reseed Patch Areas on Lawn

There will be bare spots upon removing crabgrass, which encourages weed growth. You will need to fill these bare areas as soon as possible. Here’s how to fill patch areas with new grass:

  • Rake the area: Use a garden rake to remove debris or dead plants on your lawn. Also, examine the area for damage so you can correct it before reseeding.
  • Loosen the soil: Using a garden cultivator or hard-toothed rake, break up the soil so it’s fully aerated for reseeding.
  • Spread the topsoil: You can use compost or loamy soil as the topsoil. First, sprinkle some of it and mix it with the existing soil. Then, use your hand or rake to evenly spread the topsoil around the lawn.
  • Spread grass seeds: Sprinkle the seeds across the bare spots and ensure an even spread, so they don’t pile up on one another. If you’re looking for seeds that germinate rapidly, perennial ryegrass is a good option.
  • Apply starter fertilizer: After planting the new grass seed, proceed to apply starter fertilizer to the sprouting grass stalks. This fertilizer contains a certain amount of phosphorus that promotes healthy, strong roots. Avoid applying fertilizer and seed together; this can cause uneven distribution, leading to bare areas or burning. 
  • Proper watering: Ensure you water the area regularly, and during the summer, use a burlap sheet as a covering for the patch. The burlap doubles as a shade and prevents the germinating seeds from desiccating. 

Alternatively, you can lightly spread wheat straw over the seeded area for added moisture and to keep the seeds in place. First, water the patch area daily or twice a week until the seeds sprout. Once the seeds sprout, reduce watering to twice weekly, and when grass matures, water weekly. 

7.) Mow New Grass

Allow the grass to grow a bit longer than the lawn before mowing. Also, the lawn is ready for mowing when the color of the patched areas blends in with the lawn. Some gardening experts advise mowing after seven weeks.

To reduce the population of crabgrass to the barest minimum, reseeding is an effective control measure. Reseeding promotes the growth of lawn while crowding out crabgrass and other weeds.

How Long Does It Take?

If you properly apply baking soda, it should dry out the plant tissue within two days. Upon applying the substance, it starts drying, followed by a change in color. The crabgrass dies in the following days.

Possible Side Effects

As a non-selective herbicide, baking soda can kill any other plants that it comes across. Irrespective of the concentration or amount of baking soda added to the lawn, the post-emergent herbicide has adverse effects on your lawn. 

Also, excess baking soda can destroy the soil layer or composition. For example, too much baking soda can reduce the absorption rate of grass, making it difficult to absorb nutrients, water, and minerals.

Other Uses of Baking Soda in the Garden

Baking soda is a gardener’s favorite, from tool cleaning to compost making and acting as a pesticide. In addition, it sweetens tomatoes, doubles as a fertilizer, and prevents fungal diseases. Let’s consider some of the uses of baking soda in the garden.

Baking Soda as a Pesticide

Using the right amount of homemade baking soda protects the garden against garden bugs, cockroaches, aphids, spider mites, and other pests. 

To combat spider mites and aphids using baking soda, you’ll need a cup of warm water, a quarter cup of olive oil, and one teaspoon of baking soda. Add all these and apply to affected parts regularly till spider mites and aphids are gone. 

Depending on the level of attack, you may increase the portion of baking soda to about three teaspoons. Furthermore, lightly spray the baking soda solution in crevices and hidden areas every week to prevent re-infestation.

Baking Soda as Bait to Eliminate Ant Hills

Mix equal parts of baking soda and sugar and sprinkle the solution around the ant colony or nest. This solution serves as a trap for ants, luring them to consume the baking soda solution, which results in their death over time.

To increase the solution’s effectiveness, use powdered sugar instead of granulated sugar.

Baking Soda Kills Gnats in Compost Pile and Leaf Piles

Gnats, also known as drain flies, are usually found in moist, wet areas, including sinks and drains. These flying insects can cause a nuisance in your home.

Using only baking soda may not effectively reduce the activities of these flies. However, combining baking soda with water and dish soap can kill gnats.

You can also use baking soda, boiling water, and white vinegar. Add half a cup of baking soda to a cup of white vinegar and boiling water. Then pour it down the drain or sink to ward off gnats.

Baking soda as Insect Repellent

Mix a teaspoon of baking soda and one-third mustard oil. Store the solution in an airtight container at room temperature.

For an insect repellent spray, add two teaspoons of the concentrate (baking soda and mustard oil) to a cup of warm water. Stir well and pour into a small spray bottle. 

Baking Soda as a Preventive Herbicide Against Ground-dwelling Pests, Slugs, and Cabbage Worm

Lightly sprinkle baking soda on the soil surrounding crops to keep silverfish, cockroaches, cabbage worms, and slugs at bay. 

Cabbage worms typically feed on cabbage, kale, and broccoli. Mix equal amounts of baking soda and white flour to repel these worms. Pour this mixture into a container or powder dispenser and spray your vegetables. 

Due to the buffering effect of flour on baking soda, the solution has little or no impact on the leaves of these vegetables. Apply this solution regularly, and soon enough, all the cabbage worms will die. 

Baking Soda as a Fungicide

Nothing is as frustrating and annoying as finding powdery mildew and leaf spots on crops. Thcse undesirable features do not only reduce the market value of crops; they result in fungal diseases. 

As a fungicide, baking soda disrupts ion balance in fungal cells (PDF). Baking soda mixed with dishwashing soap and water diminishes fungal effects on crops, especially ornamental plants. In most cases, it prevents the blooming of fungal spores. 

Consider using a stronger solution for long-term fungal issues. If you want to make a stronger solution, add equal parts of baking soda, vegetable oil, and dishwashing soap to a gallon of water. 

On cool days, apply this solution once a week. Avoid using the solution on plants when the sun is at its hottest since this leads to burning.

Precautions When Using Baking Soda on Your Lawn:

  • Ensure you cover other plants when applying baking soda or baking soda mixture on crabgrass.
  • Always perform a patch test on weeds before herbicide application. Apply the mixture to some leaves and leave it on for about 24 hours. If the solution burns leaves, dilute it and perform another patch test. You may have to repeat the process to get the right concentration.
  • Rinse off patches with enough water when you apply excess solution.
  • Avoid using baking soda on soil with high salt content.
  • When handling vinegar and baking soda, ensure you wear a protective mask as these household products have a strong, unpleasant smell.
  • Use baking soda sparingly. Excess baking soda can cause buildup, leading to damage to beneficial plants.

Other Homemade Crabgrass Killer Recipes

From vinegar to orange juice, salt, and dish liquid, there are several crabgrass killers you can find in your kitchen. Some of these kitchen staples are used alongside baking soda to eradicate crabgrass.

Baking Soda and Vinegar 

Like baking soda, vinegar can dry up crabgrass. Combining baking soda and vinegar will burn leaves and desiccate crabgrass from the roots. 

Add one part of baking soda to two parts of vinegar to create a solution. Spray lightly on crabgrass and repeat treatment multiple times for better outcomes. Ensure you use a small amount of the solution to avoid harming surrounding plants.

Baking Soda and Cinnamon Recipe

Cinnamon is an effective crabgrass killer; thus, it’s not surprising that it’s an active ingredient in Agralawn Crabgrass Killer.

However, while cinnamon is powerful, it’s more potent when mixed with baking soda. Here’s how to make a baking soda and cinnamon recipe.

  • Mix half a cup of baking soda in a gallon of water
  • Add a teaspoon of cinnamon bark oil or extract
  • Stir vigorously to mix ingredients
  • Then proceed to spray the solution on the crabgrass
  • Within a few hours, the crabgrass begins to dry, and by the third day, it’s completely dried.

Vinegar

Besides mixing vinegar with baking soda, you can use only vinegar to spot-treat crabgrass. For quick results, do not dilute it and ensure you apply it on a dry lawn.

Generally, 5% of vinegar will eliminate young weeds, but 9% proves more effective against stubborn and mature weeds. 

Vinegar won’t harm the soil in any way. You can apply the organic herbicide repeatedly till crabgrass dies. Due to the efficacy of vinegar, it’s known as a potent weed killer.

Salt

Another homemade crabgrass killer on the list! While it removes crabgrass, it can damage the surrounding soil if used in excess. Most gardeners who want to curb weed infestation use salt near sidewalks, patio blocks, decks, and around the foundation of the house. 

Depending on your preference, you can mix one part salt with two parts water or sprinkle salt on the weeds.

Furthermore, you can mix one-quarter table salt with a gallon of vinegar and spray where required. You’ll need to be careful when using salt as a crabgrass killer since it can destroy concrete and other plants.

Lemon Juice

For effective results, you should use lemon juice in its natural form. Meanwhile, you can use lemon juice concentrate, but you should know the dilution point. 

Use a spray bottle or dab a dry sponge with the juice to apply to the weeds. The latter may be a better option if you want to reduce the possibility of overspray. Only apply to the infested areas. 

Alternatively, you can combine lemon juice and vinegar to spot-treat crabgrass. Apply to the leaves and stems of the plant and let it sit for hours. Shortly after, the leaves will become brown or wither. To speed up the reaction process, spray the solution on plants on a hot, sunny day.

Dish Liquid

Dish liquid and vinegar make an excellent homemade crabgrass killer. Using dish liquid alone produces great results as well. Add a squirt of dish liquid to a bottle of pickling vinegar and spray on crabgrass during a hot day.

You can also use water instead of vinegar. Combine one dish liquid with ten parts water and apply to crabgrass. 

Avoid using concentrated dish liquid on your lawn. You don’t want to have dead, dried-up patches of grass since concentrated dish liquid breaks down healthy, oil-based tissue in the plant, resulting in weeds losing moisture.

Lack of moisture combined with sunlight and little heat can produce patches of crispy, brown leaves.

Alcohol

Like dish liquid, alcohol kills crabgrass by promoting moisture loss from plant cells. While rubbing alcohol may work for weeds sprouting from cracks in concrete sidewalks, you’ll need to be extra careful when using it for your lawn.

You should because excess alcohol can come in contact with other plants, depleting their nutrients and destroying the soil topography. 

Mixing alcohol with water will remove crabgrass and other weeds. Add four tablespoons of alcohol to a gallon of water and pour the solution into a spray bottle. Spray the weeds or dab with a cotton ball to wet the weed.

Within a few days, you’ll see some changes. Remember that you may need more than one application for deep-rooted plants.