Is Baking Soda Actually Good For Your Plants?

Baking soda is often talked about as a bit of a garden hero. Some people say it can help with things like powdery mildew on tomatoes or even work as a natural weed killer. But is there any real science behind these claims, or are they just garden myths?

In this post, we’re going to dive into how baking soda actually affects plants and whether it’s really safe and useful for your garden. We’ll also take a look at some common ways people use it and what can happen if you go overboard with it.

What does baking soda do in your garden?

In the garden, baking soda has a lot of potential uses, from stopping diseases to killing weeds. Here’s a closer look at how it impacts different aspects of gardening:

Preventing powdery mildew

Scientists at Cornell University discovered that baking soda can help prevent powdery mildew on vine crops and roses. It works by making the environment too alkaline for the fungus to thrive.

If you want to give it a try, mix 1 tablespoon of baking soda with a gallon of water and a teaspoon of insecticidal soap or light plant oil. Spray this mixture on your plants as soon as you spot the first signs of mildew, and repeat every 7 to 10 days. But keep in mind, baking soda is great at stopping new mildew, but it won’t fix plants that are already infected.

Killing weeds

Baking soda can also double as a non-selective weed killer. It dries out weeds because of its high salt content, which can be lethal to plants if used in large amounts.

To use it, sprinkle about 1 teaspoon directly onto the weeds after you’ve wetted them down, or mix it with water and spray it on the leaves. This method works especially well between paving stones, but be careful—it can harm nearby plants and grass if you’re not precise.

Freshening compost piles

There’s a common belief that baking soda helps eliminate odours in compost piles. While it does neutralise acidic smells (think rancid butter), it doesn’t do much for other kinds of odours. If your compost pile is getting smelly, a better fix is to add dry leaves or straw. These materials absorb moisture and help cut down on unpleasant smells more effectively than baking soda.

The impact of baking soda on different plants

Baking soda is generally safe for many plants, but it can cause problems if you use too much. Plants need a little bit of sodium, but too much can be harmful. If there’s an excess, you might notice your plants starting to droop, or their growth slowing down.

Before using baking soda on your plants, it’s a good idea to check how much sodium each plant can handle. Plants that love acidic soil, like azaleas and blueberries, are more likely to react negatively if you use baking soda on them, so it’s best to be cautious.

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Affects soil pH

When you mix baking soda with water, it can have an impact on your soil’s natural pH. This mixture has a pH of around 8.3, which means it can make the soil more alkaline. Some plants, like begonias and geraniums, actually prefer alkaline soil, so this shift can be a good thing for them.

But if you’re growing plants that thrive in more acidic conditions, baking soda might throw them off balance. It’s a good idea to keep an eye on your soil’s pH to make sure it’s just right for the plants you’re growing.

How to use baking soda in the garden

When using baking soda in your garden, it’s important to minimise risks by starting small. Test it on a small section of the plant or in an inconspicuous area first. This way, you can gauge the strength of the mixture and see how your plants react before applying it more broadly. Also, avoid using baking soda on particularly hot or sunny days, as this could burn your plants’ leaves.

Remember to stick to your regular garden care routine—watering and feeding your plants as usual. Over-relying on baking soda can disrupt the nutrient balance in your soil, potentially leading to unhealthy plants.

Better alternatives to baking soda

While baking soda can be helpful, there are other options that might be more effective and safer for your garden.

Neem oil for pest control

Neem oil is a superior alternative to baking soda for managing pests and plant diseases. Extracted from the neem tree, this natural oil breaks down easily, making it environmentally friendly and safe to use.

Unlike baking soda, neem oil targets specific pests without harming beneficial insects. It contains azadirachtin, a compound that disrupts the growth and life cycle of pests, making it effective against bugs at all stages, including eggs and larvae. Neem oil can be used year-round, offering protection during the dormant season and when plants are actively growing.

Neem cakes for natural composting

In addition to neem oil, neem cakes—by-products of neem oil production—are excellent for enhancing soil quality in natural composting. These cakes not only act as a natural pest deterrent but also provide essential nutrients to the soil. They help retain nitrogen, improving soil fertility without the negative effects associated with chemical pesticides. Neem cakes also encourage earthworms, which play a crucial role in maintaining healthy, nutrient-rich soil.

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Switching to organic fertilisers is another great alternative to using baking soda in your garden. Organic options provide plants with essential nutrients gradually, ensuring steady and healthy growth. These fertilisers improve soil quality over time and help maintain a chemical-free garden, making your gardening practises more sustainable and environmentally friendly.

Final thoughts

At the end of the day, a thriving garden comes down to balance—whether you’re using baking soda or any other remedy. Pay attention to your plants, keep their environment healthy, and choose methods that align with sustainable gardening practices. Your garden will thank you for it!

Happy gardening!

Louis Hooft

Founder & Lawn expert

Introducing Louis Hooft, the founder of MOOWY and your reliable expert. With a profound love for stunning lawns and extensive experience in garden maintenance, Louis is here to assist garden enthusiasts in achieving a greener and livelier outdoors than ever before. Count on Louis for invaluable tips, clever tricks, and top-notch products to make your garden flourish!