Garden Uses for Hydrogen Peroxide — Is It Safe For Gardening?

Last Updated on June 19, 2021 by Grow with Bovees

Garden path with tulips in bloom

You are probably aware of the various benefits of hydrogen peroxide as an oxidizer, bleaching agent and disinfectant. It is also an effective antiseptic used commonly to treat small cuts, burns, etc., for water treatment and it is also found in many personal care products such as mouthwashes, hair dyes, toothpaste, bleach, etc.

However, what you’re probably not aware of and will be surprised to learn that hydrogen peroxide is very good for your plants, great for gardening jobs and can help to keep your garden beautiful and thriving.

In this article, we’ll give you a complete lowdown about hydrogen peroxide in the garden and the different ways you can use it to keep it healthy and flourishing.

What Is Hydrogen Peroxide?

colored bottle of hydrogen peroxide

A chemical compound that occurs naturally, hydrogen peroxide or H2O2 is a pale blue-colored liquid, which is quite similar to water in terms of its chemical composition, except that it has an additional oxygen atom. Hydrogen peroxide is present in the human body, rainwater and surface water.

Hydrogen peroxide is a clear liquid that is a little more viscous compared to water. Typically, the hydrogen peroxide available in the pharmacy is a 3% or 6% solution; however, you can also get it in higher concentrations, which is generally for use in labs and industries.

Because of the oxygen-oxygen bond, hydrogen peroxide is highly unstable and decomposes when exposed to light, which is the main reason why it is usually stored in dark-colored bottles.

Is It Safe to Use Hydrogen Peroxide ?

For safe use, you must dilute the hydrogen peroxide before using it for your plants. You can figure out the strength of hydrogen peroxide from the fact that in the highest concentration, this chemical compound is used as rocket fuel.

In very low concentrations, it is quite good for your plants. The hydrogen peroxide breaks down to produce water molecules and oxygen atoms that bond together to form oxygen and may even bond with the other minerals present in the soil.

The extra oxygen is quite beneficial and the bonds formed enable the microorganisms present in the soil to use the minerals better.

However, the hydrogen peroxide must be in a very diluted form because fungi and bacteria can be destroyed even with 0.5% of hydrogen peroxide and may end up destroying beneficial bacteria and fungi too, which you don’t want.

Higher concentrations of the chemical are used to kill weeds; however, too much can be harmful to the soil and even kill your plants.

Is Hydrogen Peroxide Eco-Friendly?

miniature globe between 2 leaves

Depending on the concentration of the hydrogen peroxide and how much you use will determine its benefits. And, if used in excess, hydrogen peroxide can be quite harmful to your soil and plants.

However, since hydrogen peroxide is a natural compound and breaks down into oxygen and water, it is an eco-friendlier option compared to other artificial pesticides, herbicides and other garden treatments that are more harmful and pollute the environment.

Below, we’ll discuss some of the popular garden uses of hydrogen peroxide.

Disinfecting Tools, Pots, Potting Benches and Greenhouses

garden tools in a trug

Hydrogen peroxide inhibits antimicrobial activity and is often used in labs and medical facilities to disinfect the work surfaces and surgical tools. It is also commonly used in homes to clean various surfaces and items.

Hydrogen peroxide is an excellent way by which you can clean the various pots, garden pruning tools, containers, benches, greenhouses, etc. in your garden. You can use hydrogen peroxide of 6% to 9% concentration to sterilize everything and kill harmful pathogens and germs, while also removing dirt and stubborn marks from all the surfaces.

By dipping your gardening tools into a solution of hydrogen peroxide before using them on your plants, you can also prevent the introduction of dangerous pathogens in your plants.

A 10% hydrogen peroxide solution can kill mold spores and can also remove and prevent the growth of mildew and mold on hard surfaces such as your greenhouse walls, etc.

Soil Aeration and Treatment of Root Rot

a glass of water being emptied in garden

Good manual soil aeration is vital for the healthy growth of your plants. When the soil becomes hard and compacted, it affects plant growth because the nutrients and oxygen will not get to the plants properly.

Compacted soil can also cause root rot. Another problem is over watering your plants, which fills up the air pockets in the soil, causing a shortage of oxygen. This, in turn, causes the roots of the plants to suffocate, rot and eventually die.

A solution of 2-3 teaspoons of 3% hydrogen peroxide with 1-liter of water can help to prevent this. Pour the mixture around the base of the plants and roots carefully. Avoid watering your plants again after applying the hydrogen peroxide mixture until the soil on the top dries completely.

The extra oxygen from the hydrogen peroxide provides your plant’s roots the oxygen it needs, helps to aerate the soil and also prevents rot. Hydrogen peroxide also ensures that the roots are strong and healthy.

Spraying Fungus-Affected or Sick Plants

hand sprayer spraying insecticide

Fungal growth on your plants can cause them to become very weak and prevent them from growing properly. The strong disinfectant properties of hydrogen peroxide help to effectively combat mold, mildew and fungal growth in plants. The hydrogen peroxide oxidizes the fungus and gets rid of it.

So, if you see signs of fungal infections such as white spots, powdery mildew or rust in your plants, mix 2 cups (0.47 l) of 3% hydrogen peroxide in 1-liter of water and spray the solution on the affected plants.

Make sure to use the proper dilution because too much hydrogen peroxide can burn the plants. You can also use this solution to treat other kinds of plant infections and get rid of the harmful bacteria and soils mites from the soil.

However, an important thing to remember is that the free radical oxygen from the hydrogen peroxide can also eliminate the beneficial fungi and bacteria from the soil and so, you must use this method only if you have exhausted other methods of getting rid of the fungi from the plants.

Sanitizing Seeds With Hydrogen Peroxide Solution

The presence of any pathogens in the seeds can kill the young seedlings before they can take hold. You can prevent this by disinfecting the seeds by soaking them in 3% hydrogen peroxide for around 30 minutes before sowing them.

However, before sowing the seeds, make sure to wash them thoroughly with clean water. The hydrogen peroxide helps to kill all the harmful pathogens present in the seeds and sanitizes them.

Hydrogen Peroxide For Plants, Soaking Seeds and Washing Sprouts

seed germination in a pot

Soaking seeds in diluted hydrogen peroxide can help with seed faster germination and also ensure healthy growth in the future. Sprouting seeds require a high amount of oxygen and the extra oxygen from the hydrogen peroxide can be very beneficial. In 1 liter of water, mix 1 to 2 teaspoons of 3% hydrogen peroxide and soak the seeds in this solution.

If you have already planted the seeds, then you can use this solution to water the seedling tray. Not only does the hydrogen peroxide help the seeds to germinate faster, increases the success rates, kills any pathogens in the seeds and also helps the roots of the seedling to develop better.

If you’re growing sprouts either for commercial or for personal use, disinfecting the sprouting trays with hydrogen peroxide is a good practice to prevent contamination by bacteria like salmonella, E. coli, listeria, etc. that can cause food-borne illnesses.

Also, if your plants growing in pots are facing problems with diseases, then it may be a problem with the growing medium. Drenching the soil/growing medium and spraying the plants with diluted hydrogen peroxide can help to prevent any of these issues.

Fertilizing Your Plants

If you want the plant in your home to be fertilized better and want to strengthen their root system, using hydrogen peroxide can help with this because the extra oxygen in the hydrogen peroxide enables the plants to absorb the valuable nutrients and minerals that are present in the soil more effectively.

Mix a teaspoon of 3% hydrogen peroxide in 1 gallon (3.79 l) of warm water and pour this solution into the soil. This works as an excellent fertilizer that can help to boost the growth of your plants.

Keeping Pests Away

a fly on a flower

Hydrogen peroxide is an excellent insecticide and pesticide. Not only is it quite inexpensive, but it is eco-friendly too. Mix a cup of 3% of hydrogen peroxide with a cup of water and spray this mixture on all the plants in your garden.

The hydrogen peroxide can help to keep away common garden pests and insects such as aphids, house flies and sap-sucking pests like stink bugs, fungus gnats, etc.

The oxidizing effect of hydrogen peroxide also helps to kill the eggs and larvae of pests that are harmful to your plants.

How Often Should You Apply Hydrogen Peroxide to Plants?

The frequency of treatment with hydrogen peroxide essentially depends on the health of your plants. For healthy plants, a thorough spray with the preventative mixture of hydrogen peroxide after every rainfall is sufficient.

In case of infested or sick plants, then you should spray the plants thoroughly for around 3 to 5 days. Monitor how your plants are doing and take a call based on your judgment.

How to Use Hydrogen Peroxide on Your Tomato Plants to Prevent Fungal Diseases

tomatoes ripening on the vine

Tomato plants are quite delicate and are often susceptible to bacterial and fungal diseases. A mixture of very diluted hydrogen peroxide when sprayed on the tomato plants can help to prevent fungi such as early blight or leaf spot. The oxidation that occurs helps to kill the fungi and even mold.

To make an anti-fungal solution, mix 6 ounces (0.23 kg) or 12 tablespoons of 3% hydrogen peroxide with 1 gallon of water. You can either spray the mixture onto the tomato plants or pour it directly on the soil.

If the soil has fungus, mold or bacteria growing, then pour the hydrogen peroxide mixture into the soil like you would water the plants. This helps to kill the harmful pathogens in the soil by oxidizing them.

Alternatively, if you notice fungus or mold growing on the tomato plants, then spray the hydrogen peroxide mixture directly on the plant. This will help to kill the mold or fungus and also combat bacterial infections.

Begin by testing the hydrogen peroxide mixture on the leaves and wait for around 48 hours to see if there is any damage. If everything is fine, then you can spray all the tomato plants in your greenhouse.

To treat fungal infections on tomato plants, follow a spraying schedule of 3 days. If the infection is not too serious, then you can spray for 5 days on alternate days. Use a fungal preventative solution after spraying the hydrogen peroxide solution. Repeat the spraying process every 7-14 days followed by the fungal treatment, all through the season.

Conclusion Of Garden Uses For Hydrogen Peroxide

Hydrogen peroxide is an excellent and versatile chemical. Not only is it a great antibacterial, cleaning and bleaching agent, but it is an all-rounder in the garden too.

Hydrogen peroxide is not only inexpensive but also environmentally friendly and not as harsh on your plants as commercially-sold pesticides and insecticides. This simple chemical can work wonders in combating a variety of ailments, treat several common gardening problems and ensure that your plants and garden are healthy and blooming.