How Much Hydrogen Peroxide for Plants: Best Tips

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Last Updated on February 25, 2023 by Griselda M.

If you want to know “how much hydrogen peroxide for plants?”, then take heed of the tips in this informative blog post.

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 of 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 to the 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. 

How Much Hydrogen Peroxide per Litre of Water for Plants

So, you want to know how much hydrogen peroxide per liter of water is for plants. To start, there are several benefits to using hydrogen peroxide for plants, as it provides their roots with additional oxygen to enhance growth and germination. However, knowing the right amount that should be used in the concoctions is vital to your plant’s health and growth.

I say this because the dilution will depend on the purpose you intend to use it for. In general, a one-to-one part ratio of hydrogen peroxide and water is ideal for plants that are fully established. This would mean that a liter of water would require a liter of H2O2. Below is a breakdown that tells you the amount of hydrogen peroxide to use for each purpose.

Germinating seeds

This mixture will include two cups of water to 30mls of H2O2 3%. The seeds should be soaked in the mixture for 24 hours before planting.

Sanitizing seeds

Undiluted 3 % hydrogen peroxide should be used in this instance. Ensure that the seeds are placed in a container that seals well after covering them with H2O2. After four hours, the seeds should then be thoroughly rinsed with water.

Planted Seedlings

In this case, a solution of 30ml H2O2 3% to a liter of water is best. This mixture should be sprayed over the planted seedlings for favorable results.

Will Hydrogen Peroxide Kill Plants

So, will hydrogen peroxide kill plants? The answer to this is no, as hydrogen peroxide is safe to use on your garden plants. However, this would mean that you’d need to dilute it properly and use it moderately to keep your plants thriving. The benefits of using a hydrogen peroxide solution for your plants include the fact that it enhances the root’s nutrient absorption abilities from the soil and encourages growth.

Also, plant soil aeration increases with the addition of diluted 3% peroxide, and fungal infections are effectively controlled. But keep in mind that although the correct amount of H2O2 for plants is beneficial, giving them too much of it can result in their deterioration. Therefore, it is essential to know how much hydrogen peroxide is for plants before using it.

Hydrogen Peroxide for plants

How to Get Rid of Gnats in Plants

It is important to know how to get rid of gnats in plants if you aim to maintain a thriving garden. Fungal gnat infections can prove damaging if they’re not properly dealt with. Houseplants are prone to tiny flying bugs that perch themselves on the leaves and stems. However, all is not lost if you spot them on your plant, as they are quite easy to treat with the proper plant care techniques.

Treating gnat infections before they have a chance to lay eggs will reduce the chances of damaging your houseplant. Keep in mind that these creatures are often mistaken for fruit flies, although they are easy to tell apart. While fruit flies display stubbier legs, gnats have long legs with clear wings. Notable signs of gnat infections include stumped plant growth, yellowing leaves that fall off, root rot, and the presence of tiny flies. A hydrogen peroxide solution is amongst the most effective ways to rid of these little critters.

Here’s how to get rid of gnats in plants:

  • Combine a solution of four parts water to one part H2O2 and mix thoroughly.
  • Then, add the mixture directly to the soil that your gnat-infested plant is growing in.
  • Monitoring your plant in the next few days is vital as it will be indicative of whether the solution has gotten rid of the infection or if more should be added.
  • To continue maintaining your plant’s health after that, spray it with the solution now and then for favorable results.
  • Additionally, if you have more than one plant that is infested with gnats, then increase the amount of H2O2 solution according to your need.

Easy DIY Homemade Fungus Gnat Solution:

Using a bowl, mix together a few drops of liquid dish soap with about a cup full of white vinegar. This solution attracts gnats and should therefore be placed next to your plant for the best results. This process may need to be repeated depending on the degree of the gnat infestation. Once you have gotten rid of all the flies, you can remove the vinegar and dish soap solution.

Alternatively, you can also try fly traps or other homemade fungus gnat remedies to get rid of them.

How Long Does It Take for Hydrogen Peroxide to Kill Fungus Gnats

Ever wondered how long it takes for hydrogen peroxide to kill fungus gnats? Applying the 3% hydrogen peroxide and four-part water solution to your plant will result in the death of gnat larvae on contact. This means that the H2O2 solution will get rid of fungus gnats as soon as it comes into contact with them. However, for it to be this effective, you must ensure that the top layer of the soil is dry before adding the hydrogen peroxide mix.

Also, keep in mind that after the fizzing has stopped, the solution breaks down and converts to oxygen and water molecules that become ineffective. Therefore, repeating the process as needed to get rid of fungus gnats is necessary. Remember that knowing how much hydrogen peroxide is for plants is an important part of getting rid of them effectively.

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

Hydrogen Peroxide Benefits for 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 most prominent solution 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.

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 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. 

Can I Use Hydrogen Peroxide on My Plants every day?

Quite often, we have been asked, can I use hydrogen peroxide on my plants every day? Although you can use diluted hydrogen peroxide daily, it is not advised. This is because too much of it can be harmful to your garden plants and may even result in destroying them completely. Just like how many things in exorbitant quantities can prove disastrous, this particular product is no exception.

Therefore, it is recommended that you spray your plants weekly with a diluted hydrogen peroxide solution as it is much safer to do so. Keep in mind that you also need to consider what you are using the solution for. In this case, if it is being sprayed on the foliage as a preventative measure, then weekly applications are recommended. However, if your plants have already been invaded by insects and other pests, we advise that you spray them twice or thrice per week to rid them of these unwelcomed creatures.

What Can You Use Instead of Hydrogen Peroxide for Plants?

If you want to know what can you use instead of hydrogen peroxide for plants, then taking heed of the following information would be beneficial. Hydrogen peroxide is often used on plant foliage to prevent or get rid of bug infestations and other bacteria and fungi that flaw your plant’s health and growth. However, there are other useful things that you can use instead of them if you prefer.

These include a clump of human hair combined with a few handfuls of compost as it serves as fertilizer for your plants according to some sources. Neem oil is also an excellent natural method that can be used on plants that are wilting or not growing their best. Several insect repellents are specially made for plants that you can easily find online or at your local nursery or home and garden center. Other natural home remedies to use instead of hydrogen peroxide include garlic, eggshells, balsamic vinegar, and cedar oil.

How Do You Revive a Dying Plant With Hydrogen Peroxide?

Ever wondered how you revive a dying plant with hydrogen peroxide? This product can be used as a preventative measure or to get rid of bugs and other insects or the build-up of bacteria and fungus in garden plants. To revive your plant, using a solution of  50ml hydrogen peroxide to four liters of water would be an effective mixture.

Thereafter, you should soak your plant roots in this solution for about six hours or so. Then, using new nutrient-rich potting soil that has excellent drainage properties, replant in a new pot. Using the same hydrogen solution, thoroughly soak the soil. Rewater with the peroxide mix every two to three days and you should see your plant regaining its health in no time.

How Do You Treat Aquarium Plants With Hydrogen Peroxide?

If you have a fish tank and want to know how you treat aquarium plants with hydrogen peroxide then we have some great information for you. To begin with, it is advisable to use 3% hydrogen peroxide when making a solution for your plant. This mixture should contain 30ml of the peroxide and a gallon of water. Thereafter, take each of your aquarium plants, give them a gentle rinse under tap water, and then soak them for about five minutes or less in the hydrogen peroxide solution. This treatment is essential in maintaining your plant’s health and growth and preventing bacterial buildup.

Can You Mix Epsom Salt and Hydrogen Peroxide for Plants?

In truth, can you mix Epsom salt and hydrogen peroxide for plants? Although you can mix these two products to use on your garden plants, it is not advisable. This is because Epsom salts are used as a magnesium sulfate foliar feed that keeps your plant thriving, while hydrogen peroxide is used as a preventative measure to keep insects at bay, get rid of infestation and fungus, and encourage root health.

For this reason, it is best to use both these products on their own. They are easy to dilute in water and are very beneficial to maintain the stature of garden plants. Remember that both these products can be used to revive your overall plant.


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 you must 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.

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. Others 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 in 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.

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