How to Use Baking Soda to Grow Hydrangeas: Tips and Techniques


If you’re a gardener or someone who loves to have a beautiful garden, you may have heard about using baking soda to grow hydrangeas.

Baking soda is a versatile household ingredient that can be used for various purposes, including gardening.

In this article, we will explore the tips and techniques on how to use baking soda to grow hydrangeas successfully.

Benefits of Using Baking Soda for Hydrangeas

Baking soda, also known as sodium bicarbonate, offers several benefits when used for hydrangeas.

It helps in maintaining the pH level of the soil, which is crucial for the healthy growth of plants.

Additionally, baking soda acts as a natural fungicide, preventing the growth of fungal diseases on the plant.

It also aids in the absorption of nutrients by the plant roots, leading to better overall growth and blooming of hydrangeas.

Testing Soil pH

Before using baking soda on your hydrangeas, it’s essential to test the pH level of your soil. Hydrangeas thrive in acidic soil, with a pH level between 5. 2 and 5. 5.

If your soil is alkaline, adding baking soda can help lower the pH level and create a more suitable environment for hydrangeas to grow.

To test the soil pH, you can purchase a soil testing kit from a local garden center or use a pH meter.

Follow the instructions provided with the kit or meter to obtain an accurate reading of your soil’s pH level.

Adjusting Soil pH with Baking Soda

If your soil pH is higher than the desired range for hydrangeas, you can use baking soda to lower it. Here’s how:

  1. Calculate the amount of baking soda needed: For every 10 square feet of soil, you will need approximately 1/4 cup of baking soda.
  2. Sprinkle baking soda on the soil: Evenly distribute the calculated amount of baking soda on the soil surface around the base of the hydrangea plant.
  3. Water the soil: After applying baking soda, water the soil thoroughly to help the baking soda penetrate and mix with the soil.
  4. Monitor the pH level: Test the soil pH periodically to ensure it remains within the desired range. If needed, reapply baking soda to maintain the optimal pH level.

Using Baking Soda as a Fungicide

Baking soda can also be used as a natural fungicide to prevent and control fungal diseases on hydrangeas.

The alkaline nature of baking soda creates an unfavorable environment for fungal growth. Here’s how to use baking soda as a fungicide:

  1. Create a baking soda solution: Mix 1 tablespoon of baking soda with 1 gallon of water. Stir well to dissolve the baking soda completely.
  2. Spray the solution on the plant: Using a spray bottle or a garden sprayer, apply the baking soda solution to the leaves, stems, and flowers of the hydrangea plant. Make sure to cover all parts of the plant thoroughly.
  3. Repeat as necessary: Apply the baking soda solution every 1-2 weeks or after heavy rainfall to maintain the protective barrier against fungal diseases.

Additional Tips for Growing Hydrangeas with Baking Soda

  • Avoid over-application: While baking soda can be beneficial for hydrangeas, it’s important not to over-apply it. Excessive use of baking soda can lead to an imbalance in soil pH, which may negatively affect the plant’s health.
  • Watering: Hydrangeas require regular watering, especially during hot and dry periods. Ensure the soil remains moist but not waterlogged. Baking soda can help retain moisture in the soil, but it should not replace proper watering practices.
  • Mulching: Applying a layer of organic mulch around the base of the hydrangea plant can help conserve moisture, regulate soil temperature, and suppress weed growth. Mulching also adds organic matter to the soil, promoting healthy root development.
  • Pruning: Prune your hydrangeas during the appropriate time of the year to maintain their shape and encourage new growth. Remove any dead or damaged branches to improve the overall health of the plant.


Using baking soda to grow hydrangeas can be a beneficial technique for gardeners. It helps in adjusting soil pH, preventing fungal diseases, and promoting overall plant health.

Remember to test your soil pH before applying baking soda and monitor the pH level regularly.

With proper care and the right use of baking soda, you can enjoy beautiful and vibrant hydrangeas in your garden.

Frequently Asked Questions

How often should I apply baking soda to my hydrangeas?

You should apply baking soda to your hydrangeas as needed, depending on the soil pH and the presence of fungal diseases.

Test the soil pH periodically and reapply baking soda if the pH level is higher than the desired range.

For fungal prevention, apply the baking soda solution every 1-2 weeks or after heavy rainfall.

Can I use baking powder instead of baking soda for my hydrangeas?

No, baking powder cannot be used as a substitute for baking soda in gardening.

Baking powder contains additional ingredients, such as cream of tartar and cornstarch, which are not suitable for plants. Stick to using pure baking soda for your hydrangeas.

Can I use baking soda on other plants besides hydrangeas?

Yes, baking soda can be used on other plants as well. It helps in adjusting soil pH and acts as a natural fungicide.

However, it’s important to research the specific needs of each plant before using baking soda, as different plants have different pH requirements.

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