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Hydrogen Peroxide for Plants and Garden. How Much Hydrogen Peroxide to use on Plants

Hydrogen Peroxide for Plants and Garden. How Much Hydrogen Peroxide to use on Plants

Hydrogen peroxide is a chemical compound used for a variety of purposes and plants happen to fall into one of those varieties in the application of hydrogen peroxide. If you are previously unaware of this and you intend to dispose off the hydrogen peroxide you have after exhausting all its chemical uses, you might want to put that action on hold after reading this. Hydrogen peroxide comes with some garden benefits which you are about to learn of. However, you are aware that when it comes to chemicals, the dosage is paramount. If you apply too much, it could be dangerous, and if you apply less of it, there will be little or no results and so it all falls down to moderate application or required concentration. If you will be using hydrogen peroxide for all its benefits offerings to your plants, then you need to know how much Hydrogen Peroxide for plants is needed. 

But before we delve into that, let’s look at some of the benefits of Hydrogen Peroxide for Plants. 

Hydrogen Peroxide Benefits for Plants
Hydrogen Peroxide for Plants and Ga...
Hydrogen Peroxide for Plants and Garden How Much Hydrogen Peroxide to use on Plants

Hydrogen Peroxide can be used in the garden for the following purposes which are beneficial to the plant. 

For Watering Plants: By its chemical formula H2O2, hydrogen peroxide is almost the same as water, the sole difference is the addition of an extra atom of oxygen and so it can be used as water to mist plants, soak seeds, or used to wash sprouts. 

Fungus Killer Spray: If your plant is sickened by a fungus, you can spray hydrogen peroxide on it to inhibit the growth of the fungus. Hydrogen peroxide can also be used to treat root rot. The extra atom of oxygen does most of the healing. 

Boost Plant Growth: Although it won’t pass for a fertilizer, the hydrogen peroxide compound can also stimulate plant growth due to the extra oxygen it gives to the plant. The extra oxygen atom is there to help the root of the plant absorb nutrients better from the soil. 

Other Uses: Hydrogen Peroxide can also be used as a weed killer in higher concentrations, used for pest control, preventing infections on plants, and for pre-treating seeds. 

How Much Hydrogen Peroxide Is Sufficient for Plant?

Now that the benefits have been brought to light, it all narrows down to the application which if gotten wrong can be disastrous to the entire mission. So the concentration is of the essence as about 10% of hydrogen peroxide is already a weed killer so if that concentration is added to the plant, it will terminate its existence untimely. When using hydrogen peroxide for plants, the solution should be diluted to reduce the concentration and make it useful to the plants as opposed to threatening their existence. The solution that is most prominent is the 3% hydrogen peroxide solution and there is a variant of 35% in concentration. You can always find the 3% solution at the drug store close to you. Both percentages still need to be diluted before using them on your plants. If you are trying to cover a large area of greenery or your garden is huge, or maybe it’s a large farm you are dealing with, then the 35% is the ideal option to go for.

Now let’s look at two uses of hydrogen peroxide and the required concentration for application. 

For Watering Plants

If you are using the 3% solution to water or mist plants, 1 or ½ teaspoons of the hydrogen peroxide solution should be diluted with a cup of water. 2 tablespoons should be diluted with a quarter of water, ½ cup of the solution should be diluted with a gallon of water, 2 cups with 5 gallons of water, 5 cups with 10 gallons of water and 10 cups with 20 gallons of water.

Hydrogen Peroxide for Plants and Garden. How Much Hydrogen Peroxide to use on Plants

To prepare a 35% solution:

7 to 10 drops should be diluted with 1 cup of water, ½ teaspoon with 1 quarter of water, 2 teaspoons with 1 gallon of water, 3 tablespoons and 1 teaspoon with 5 gallons of water, 6 tablespoons, and 2 teaspoons with 10 gallons of water, ¾ cup, 1 tablespoon and 1 teaspoon with 20 gallons of water. 

To Spray on Plants Plagued by Fungus

For the 3% hydrogen peroxide solution:

1 tablespoon should be diluted with 1 cup of water, 2 tablespoons with 1 pint of water, ¼ cup with 1 quarter of water, 1 cup with 1 gallon of water, 5 cups with 5 gallons of water, and 10 cups with 10 gallons of water.

Hydrogen Peroxide for Plants and Garden. How Much Hydrogen Peroxide to use on Plants

For the 35% solution of hydrogen peroxide:

¼ teaspoon should be diluted with 1 cup of water, ½ teaspoon with 1 pint of water, 1 teaspoon with 1 quart of water, 1 tablespoon and 1 teaspoon with 1 gallon of water, 6 tablespoons with and 2 teaspoons with 5 gallons of water, and ¾ cup, 1 tablespoon and 1 teaspoon with 10 gallons of water. 

Precautions; when diluting, never add the water to the solution, hydrogen peroxide is a higher oxide and the presence of hydrogen ions makes it a little acidic. It could splatter and spill on your skin if you add water to it causing your skin to burn. Always add the solution to the recommended amounts of water. This rule is to be followed too when applying it to the plants. Be careful not to let it get to your skin. Use hand gloves for protection. You should also note the difference in the amount of water used in diluting the 3% and 35% solutions, don’t interchange them. It’s always better to have more water than more of the solution. 


Hydrogen Peroxide is a chemical compound and you should have that in mind whenever you intend to use it. The consciousness of its chemical properties which can be dangerous will help you in applying the precautions and using the right concentrations. The right amount is and will always remain beneficial to your plants when you use the solution, too much of it can afford you the direct opposite of whatever you are trying to achieve. So it’s necessary you stay guided.


How long does hydrogen peroxide stay active in the water?

The period that hydrogen peroxide stays active in water depends on how clean or dirty the water you used to mix with it.

Distilled water or deionized water will last indefinitely. But tap water contains impurities that react with H2O2 and makes it less effective. This happens over a short period of time.

How often should you use hydrogen peroxide on plants?

Water mature plants with the hydrogen peroxide solution once a week or after it rains. 

Mix equal parts of distilled water and 3% hydrogen peroxide. Using a spray bottle, thoroughly soak the infected plants and the area around them. Be sure to get to the underside of the leaves as well. You may also use this solution when transplanting and when starting root cuttings. Hydrogen peroxide is known to treat and prevent pest infestation.

Will hydrogen peroxide kill bugs in the soil?

A 1% hydrogen peroxide solution is safe to use in your garden and will keep away insects and bugs. Some insects and bugs are helpful to your garden. There are others that are outright pests and they damage your crops. Rather than trying to kill everything, a kinder way to put off the pesky bugs is by using this solution. 

A hydrogen peroxide solution is a non-toxic option for chemical pest control. It is safer and cheaper than some of the insecticides bought from stores. These insecticides can be full of toxic chemicals that are harmful to pets and other wildlife. The 1% hydrogen peroxide solution will keep away insects and kill any eggs.

Will hydrogen peroxide kill aphids on plants?

Aphids are one of the top 10 gardening problems. These little sap-sucking monsters are devastating to any farmer. They are commonly found in groups and you will find them feasting on your plants.

Hydrogen peroxide has many uses and one of them is to eliminate aphids. As a concentrate, it is a bleach and when diluted it’s antimicrobial. These properties are a valuable weapon against aphids. The hydrogen peroxide solution kills aphids population in your plants’ soil. Use a 1-3% solution to avoid harming the plants. Soak the infested plant and soil with this solution. Use a spray bottle to apply the peroxide in case the aphids are not visible especially during repotting.

Can you sterilize soil with hydrogen peroxide?

If you want to sterilize your potting soil using hydrogen peroxide is the best way to go. This method is simple for any new gardener to use. It does not require many skills but it’s very beneficial. 

Using hydrogen peroxide to sterilize your soil will take two simple steps. These are: 

Step 1: Provide a big bucket enough to mix the hydrogen peroxide concentrate with water. Mix enough solution to thoroughly spray the soil. 

Step 2: Spray the solution thoroughly. Use a spraying device to carry out this task. There are readily available sprayers in many different sizes in garden centers near you.

Get a sprayer that can at least accommodate 20 gallons of water. You need to determine how much hydrogen peroxide you will need for 20 liters.

Do not apply hydrogen peroxide directly to the soil as it is highly concentrated and needs to be diluted before use.