6 Surprising Benefits of Baking Soda in Gardening: A Gardener’s Secret Weapon

Baking soda is a gardener’s secret weapon, offering a natural and affordable way to care for plants while keeping pests and diseases at bay.

Whether you’re dealing with fungal infections, unwanted weeds, or soil issues, this simple household ingredient can make a significant difference.

Below are six ways to use baking soda to improve your garden’s health and productivity.

1. A Powerful Natural Fungicide for Disease Prevention

Fungal diseases such as powdery mildew, black spot, and early blight can wreak havoc on plants like tomatoes, cucumbers, squash, and roses.

Studies have shown that sodium bicarbonate (baking soda) is effective in controlling certain fungal pathogens by disrupting fungal cell membranes. The Journal of Plant Pathology reports that bicarbonates can suppress powdery mildew without the harmful side effects of chemical fungicides.

How to Use:

Mix 1 tablespoon of baking soda, 1 gallon of water, a teaspoon of vegetable oil, and a few drops of liquid soap, then spray this solution on affected plants every one to two weeks, especially during humid conditions that favor fungal growth.

You should avoid excessive use, as it can build up salt deposits that might affect plant health.

2. Enhances Soil Quality and pH Balance

Soil acidity directly affects plant growth. While most garden plants thrive in slightly acidic to neutral soil (pH 6.0–7.0), overly acidic conditions can lead to nutrient deficiencies and poor plant performance.

Baking soda can help stabilize soil pH in small amounts.

How to Use:

First, test your soil’s pH before application. If it’s too acidic, lightly sprinkle baking soda (about 1 teaspoon per square foot) and water it in. Avoid applying too much, as excessive sodium can affect soil structure and plant health.

3. A Safe and Effective Pest Repellent

Many garden pests, including aphids, ants, and slugs, dislike baking soda because it dehydrates them and disrupts their feeding patterns. Unlike chemical pesticides, baking soda is safe for beneficial insects like ladybugs and bees.

How to Use:

• For ants and aphids: Mix 1 tablespoon of baking soda with 1 teaspoon of liquid dish soap and 1 quart of water. Spray it on plants where pests are present.
• For slugs and snails: Sprinkle a thin layer of baking soda around the base of plants to create a protective barrier. Be cautious, as direct contact with excessive baking soda can damage tender plant stems.

4. Improves Compost Quality and Reduces Odor

Composting relies on microbial activity, which thrives in a balanced pH environment. Baking soda helps keep the conditions optimal for beneficial bacteria, ensuring your compost turns into rich, fertile soil faster.

How to Use:

You just add a light sprinkle of baking soda to your compost heap when turning it. However, avoid overuse, as too much alkalinity can slow down the decomposition process.

5. Cleans and Sanitizes Garden Tools

Rust, bacteria, and fungal spores can linger on gardening tools, potentially spreading diseases from one plant to another. Baking soda is a natural abrasive that helps scrub away dirt while acting as a mild disinfectant.

How to Use:

First you make a paste with equal parts baking soda and water, then apply it to pruning shears, trowels, and other tools, scrubbing with a brush before rinsing.

For an extra cleaning boost, add white vinegar to break down rust.

6. A Natural Weed Suppressant

Weeds compete with garden plants for nutrients, water, and sunlight. Baking soda can help control unwanted weeds growing in driveways, garden paths, or cracks in pavement without the use of harsh chemicals.

How to Use:

Sprinkle baking soda directly onto weeds growing in hardscapes or cracks. The sodium content dehydrates the weeds, effectively killing them within a few days.