Garden Uses For Hydrogen Peroxide: Will Hydrogen Peroxide Hurt Plants

By: Amy Grant

You no doubt have some hydrogen peroxide in your medicine cabinet and use it on minor cuts and scrapes, but did you know that you can use hydrogen peroxide in the garden? There are actually a number of garden uses for hydrogen peroxide. Read on to find out how to use hydrogen peroxide for plants.

Does Hydrogen Peroxide Hurt Plants?

Almost anything in large quantities can be harmful, and using huge doses of hydrogen peroxide on in the garden is no exception. When using hydrogen peroxide for plants, however, the solution is generally diluted, making it especially safe. Also, it is recognized by the United States EPA, giving it an extra seal of approval.

Hydrogen peroxide is also made up of the same atoms that water is made from with the exception of an additional oxygen atom. This extra oxygen (H2O2) gives hydrogen peroxide its beneficial properties.

So, the answer to the question “does hydrogen peroxide hurt plants” is a resolute no, provided the strength is sufficiently diluted. You can purchase hydrogen peroxide in various potencies. The most commonly available is a 3% solution, but they go up to 35 %. The 3% solution is the type readily available at the grocery or drug store.

How to Use Hydrogen Peroxide

Hydrogen peroxide can be used for any of the following in the garden:

  • pest control
  • treating root rot
  • pre-treating seeds
  • foliar spray to kill fungus
  • infection preventive on damaged trees

While it has also been used as a general “fertilizer” either added in during watering or sprayed onto the foliage, hydrogen peroxide is not fertilizer, but it can help boost plant growth. How exactly? Hydrogen peroxide helps encourage healthy root growth because of the extra oxygen molecule. Oxygen can help plant roots absorb nutrients from the soil. Therefore, this extra bit of oxygen better enables the roots to absorb more nutrients, which means faster, healthier, and more vigorous growth. And as a bonus, hydrogen peroxide can help discourage unwanted bacteria/fungi that may be lurking in the garden.

To give plants an added boost of oxygen or for pest control using the 3% solution, add 1 teaspoon per cup of water in a spray bottle and mist the plant. This amount is also suitable for pre-treating seeds to control fungal infections. For plants with root rot or fungal infections, use 1 tablespoon per cup of water. The solution can be made up and stored for future use, but be sure to store it in a cool, dark place as exposure to light diminishes the potency.

If you want to cover a larger area, it might be more economical to purchase the 35% hydrogen peroxide. Mix one part hydrogen peroxide to ten parts of water. That is one cup per four square feet (1.2 square m.) of garden. Mix the solution in a watering can or into a large sprayer. Water at the base of the plants and avoid wetting the foliage. Be very careful when using this percentage of peroxide. It can bleach and/or burn the skin. Spray the veggie garden after every rainfall or as needed.

Not only is this an environmentally friendly alternative to pesticides, but it has the added benefit of being anti-fungal and gives plants a healthy boost of oxygen too. Also, 3% peroxide solutions are commonly available (even at the .99 cent store!) and generally extremely economical.

This article was last updated on

Read more about Soil, Fixes & Fertilizers

1 cup 1 tablespoon 1/4 teaspoon
1 pint 2 tablespoons 1/2 teaspoon
1 quart 1/4 cup 1 teaspoon
1 gallon 1 cup 1 tablespoon plus 1 teaspoon
5 gallons 5 cups 6 tablespoons plus 2 teaspoons
10 gallons 10 cups 3/4 cup plus 1 tablespoons plus 1 teaspoons
20 gallons 20 cups 1 and 1/2 cups plus 2 tablespoons plus 2 teaspoons

Please be mindful to choose the correct column in the chart depending on whether you are using 3% hydrogen peroxide or 35% hydrogen peroxide!!

As you may notice, the amount of peroxide in the chart for sick and fungusy plants is twice as much as in the first chart. I have heard of people using stronger solutions, but more is NOT always better. So be careful, and when in doubt, stay safe. You can always apply more another day. If you decide to use a bit more, please make it only a little bit more, don't get carried away. Gardening with hydrogen peroxide is great, but too much can harm your plants.

‏What is hydrogen peroxide?‏

‏Hydrogen peroxide is a colorless, chemical compound with the formula H202. Surprisingly, it only contains one extra oxygen molecule than water. This extra oxygen molecule, however, creates a strong and powerful oxidizer that’s capable of killing bacteria and viruses. This makes it a popular household cleaning product but it also has several other uses. ‏

Hydrogen Peroxide Uses

1. Hydrogen Peroxide Uses Against Root Rot

Overwatering causes the shortage of Oxygen at the root zone. If you overwater the plant, the water fills the air spaces in soil and the plant’s roots suffocate due to the lack of air and they begin to die after 24 hours. To save such a plant from this problem, water it thoroughly with 3% hydrogen peroxide mixed in 1 quart of water. The extra oxygen in the hydrogen peroxide provides the roots their much-needed oxygen to survive. After this, don’t water the plant until top 1 or 2 inches of soil dries out well.

Read more about this here

2. Using Hydrogen for Faster Seed Germination

You can use hydrogen peroxide to help seeds germinate more quickly. Hydrogen peroxide softens the coat of seeds and kills any pathogen present on seed coat thus increase the germination rate and help the seed germinate faster. Soak your seeds in a 3% hydrogen peroxide for 30 minutes. Rinse the seeds several times with water before planting and plant them as usual.

3. Hydrogen Peroxide for Mold and Mildew

Hydrogen peroxide has an oxidizing property that is fatal for mold and mildew. Mix a liter of water with 10 tablespoons of 3 to 6% hydrogen peroxide depending on the level of infection. Spray this solution on plants daily until the fungus disappears.

4. Hydrogen Peroxide as a Fertilizer

Use hydrogen peroxide to help strengthen the root system of your plants. Hydrogen peroxide has one extra oxygen molecule (than water) that helps plant’s roots to absorb nutritions from soil more effectively, you can use this formula occasionally to boost the growth– Mix about 1 teaspoon of 3% Hydrogen peroxide with 1 gallon of water.

*Read more about this on eHow here.

Caveat: Make sure that you do not use more concentrated hydrogen peroxide as it can kill plants. 3% strength is the most familiar concentration and usually recommended.

5. To Keep Pests Away

The hydrogen peroxide can be used as a pesticide. Spraying the plant thoroughly with 3% hydrogen peroxide mixed in the equal amount of water kills the pests and their eggs. The hydrogen peroxide also kills the bacteria that develop on fruits and vegetables.

Pin it


Most Important Habits Every Indoor Plant Owner Should Adopt

21 Easy Things that’ll Solve All Your Houseplant Problems

How to Keep your Ferns Lush and Beautiful


do y’all think this would kill army worms?

I don’t think it would but you could always try. Maybe, putting a worm in a pot with little soil, spray some in there and check back in 2 days. Spray both days.

Interesting article, I’ll give it a try.

Could these tips be used for indoor plants as well

I sub to a couple of YouTube orchid channels. Both use H.P. often: whenever a cut needs to be made, for tiny snails and slugs that get in, for fungus, root rot, etc.
Stick with 3% and most plants will be OK. Not sure about African Violets or other very tender ones.

I put worms in my flower beds because here in Ms. the soil has a lot of clay the worms crawling around (I bought the at a fish bait stand) keep the soil from getting to packed and they leave good fertilizer.

look at “worm tower” on you tube.

I will try anything that will kill grubs…

Beer, they love it and drown!

The beer needs to be in a saucer so that the grubs will drown.

How much hydrogen peroxide should be added to 1 quart of water?

Read the links in the blue letters

Same question as Meryl… You did not state the mix ratio on the first few uses… Thanks!

Could it be used in a compost tumbler? To kill the odor of dried and old compost?

Worms deodorise very well. Put them in there and the next day it should be fine.
I like worms in my compost. My whole garden is a compost heap of mulch. I have heavy black soil that compacts hard. Worms break it up after a while and it becomes sweet smelling and crumbly.
Kind regards

It sounds like you have a wonderful gardening soil to work with! I only wish that I could get my soil up to par It has rocks and is so compacted and it’s graded on a sloop which I find it very difficult to make it useful for planting things especially a fruit tree. Any suggestions would be greatly appreciated!

Does it kill beneficial nematodes?

Will the mixture work on killing mold and mildew under kitchen sink and rotted wood? What do I use to kill a climbing vine weed outside of house that grows from underneath the closed in porch and can’t get to roots? Thanks Cindy

Try one gallon of vinegar 1 cup salt 2 tablespoos dish liquid. But don’t spray on anything you don’t want killed. Spray whe it’s not going to rain. Do it again in a couple of days. This works for me. With poison ivy.

Mix about 1 teaspoon of 3% Hydrogen peroxide with 1 gallon of water.

I put some in my water fountains to keep the mold/moss from growing and it’s not harmful to the wildlife.

3%? Is this foodgrade HP (not the stuff we buy in the drugstore)?

There is no such thing as foodgrade Hydrogen Peroxide. HP is toxic to animal life forms. I’m not even all that sure about plant life forms. By what means is the “extra” hydrogen ion being separated from the other ions in the molecule? What is the catalyst or the process that turns H3O into H2O and H+?

try diatomaceous earth (FOOD GRADE ONLY).

my answer was meant for the first question.

i put that in my dogs food..can it be put in soil 2?

What are you putting in your dogs food?? Hydrogen peroxide?? WHY!!

Excellent stuff !
Crawling bugs hate it! Cuts their legs ! Really !

Food grade PEROXIDE is sold in 35% just add water to it until it reaches 3 % .It is used by the food industry extensively.

There is such a thing as food grade H2O2. My 95 year old parents drink it mixed with water or juice. Must be diluted of course. Google it.

H2O2 is just that unstable. It doesn’t want to exist and is trying to shed that extra O2.

Hi- There IS FOOD GRADE HYDROGEN PEROXIDE and it’s a MIRACLE WORKER. Most don’t know about it BECAUSE of how beneficial it is to our health. Only need drops. It can save lives.

Hydrogen peroxide is H2O2, not H3O

Would this kill mosquito larva in standing water?

would like to know as well… I have been wanting to make some containers to catch rainfall because we are always in a drought in south Texas. So far I have read articles of people using gold fish to eat the larva, some have used a fish tank bubbler to a movement on the water surface to prevent mosquitos from laying their eggs. if HP works on killing larva, I would think this is the easiest and cheapest route.

Gold fish super cheap also.

Hi-Try covering as much as you can if possible, a little bleach is used in livestock troughs, can also put things that float (ball, bath toy-to try to keep surface moving-we use them in winter to help prevent ice in horses trough when no electric avail.). or maybe screen lid, lemongrass plant or wind chime or spinner (last 2 they’re just my guesses).

I made screen covers for 2 waterbarrels to keep the mosquitoes out.

Try fish in the water. They eat the larvae. My pond is so free of mosquitoes thanks to them.
the pond pump helps to oxygenate the water. It is clear, The fish are healthy. I am growing plants in there too. Beautiful waterlilies especially.

I use 3% hydrogen peroxide to kill the pests present in the roots of orchids before repotting them .

Very cool. I love learning something new. Thanks.

Mosquito donuts are for sale. For standing water they last a month or more. I use them in our waterfall pond.

Or add a few table spoons of cooking oil, To the standing water. The oil spreads out and floats on top of the water and suffocates the mosquitoes . Won’t harm plants or animals…amd super cheap.

I live in central Florida and I have used Hydrogen peroxide (bought in grocery store) for over a year in my bubbling water feature and it does keep the water clean, no nasty green stuff. I have to add 8 oz to the pot holding the water (4-5 gallons) once a month as I also have to add water that evaporates.

Very useful information thanks

This may be too much info, but judging from the questions some may benefit
1. there are 2 commercially available strengths of “peroxide”: 3% and 20%.
3% is the one referred to in ALL of the
references to in gardening. For example, it was stated using 1 tsp per gallon of water, but there are many variables to this: how long has the mixture been sitting since it was mixed? Has the mixture been sitting in the shade of sun? Hydrogen Peroxide is a relatively unstable compound I.e., it has an extra oxygen atom that it does not want: H2O2 very quickly breaks down into water (H2O) plus one atom of oxygen (O). Ever notice when cleaning a wound using peroxide (always the 3%!) that bubbles are released…those are the extra oxygen atoms forming the bubbles (which kill bacteria & help to clean the wound). That quick formation of bubbles shows just how “unstable” H2O2 is, to be of benefit, a mixture should be used quickly.

There are many beneficial uses of peroxide (ask your pharmacist) HOWEVER unless you intend to bleach your hair,NEVER have the 20% strength in your home…it can cause burns & can be deadly if ingested.

I’ve had inclinations to use it but was afraid it would burn the leaves…My ivy has been sad after she got too much rain on her pot. You think she can take it?

Yes, HP is a very practical product to keep around the house for cleaning–for soaking seeds before planting thereby getting a better germination and also ridding molds that commonly occur on seeds right after planting. Hydrogen peroxide is excellent for certain infections including staph–but never use peroxide on a gap wound or a deep puncture injury. In these cases the peroxide will disinfect, but also it will keep the wound from closing back up properly. Farmers often have made this mistake using it on minor wounds of animals but then using it on horses or cows that have deep punctures–in these cases it may even keep the injury from healing because the flesh will not grow back properly. It has been used successfully for cancer by patients and even some MD’s. The atom of oxygen that separates from the molecule when taken internally does the same thing that white blood cells do when a person has an infection—white blood cells produce peroxide to heal.

Will it help get rid of mealy bugs on my Hoya and white flies on my Gerber ?

HP can be used to help rid white flies and also mold. It often leaves brown spots on leaves and may wilt leaves slightly–these symptoms dissipate quickly and the plant or shrub usually receives quite a benefit.

Always use it at the proper dilution rate. I am not recommending the use of it when I talk about the various ways it has been used-simply disclosing information.

Many of this works most off the problems are solved.I did used them ,till now no complains .most

I use it in my Koi pond to help keep the gravel bottom clean, it doesn’t harm the fish or pond plants used correctly.

Will a mixture of peroxide and water help powdery mildew on various plants, like peonies or tall phlox?

Diatomaceous Earth (I use food grade only)kills ALL Insects, including beneficial ones- dont use in soil you want earthworms to live in, and not around FLOWERS- bees will get killed too ! I sprinkle it very carefully on lower leaves of my food plants not on the flowering parts – love the Hydrogen Peroxide info though ! Will TRY !

Would the 3% be helpful for “Fish Tanks” to control issues mentioned regardind ponds?
JMAS, Homestead, FL.

Hi, different subject than gardens. Could HP be used (larger quantities) in a small 2 person hot tub, rather than the strong chemicals?

I use hp that is used for swimming pools and spas 50% 10 mils to 160 mils water 100 mils will make 1.6 liters at approx 3% works well I get mine from good splash Newcastle NSW never had any problem with it

I have used the 3% for years. I just pour some like a fourth of a cup in a gallon of water and go watering plants. I have revived plants that looked almost dead. My rose bush started blooming like crazy. I have heard you can put it on your lawn. I didn’t know about it getting rid of white flies so I will have to try it on my lemon trees. It should not hurt you to drink a little because I have had a dentist tell me to rinse with it. It really works.

Have you tried using a full bottle in 1L bottle thats about close half/half

I used 1 bottle (3%) (400ish ml) in my hydroponics jar, for my herb (oregano) 4 parts to 1 part water. Its been 24hrs, no signs of any ill effects on the leaves, stems, or roots.

Reason I did that is because it showed signs of root rot.
at the end of the day, after all the O2 is released, you are just left with H2O (aka water) .. I’m curious if i can drink it :D … the 97% of the mixture IS distilled water.. probably not a good idea since its acidic.

Does anyone know the PH reading on HP?

Four parts ho to one water?! Don’t you mean the other way around?!

Powdery mildew can be counteracted with a combination of baking soda and canola oil. Of if desired the canola oil can be used alone. 1 tbs of baking soda pr gallon of water with 2.5 tbs of canola oil. The oil suffocates the mildew. Many types of oils are used for row crops as well.

Does the mixture of 3% HP with water can kill or repellent termite too?

My jade plant got white flies. I got lucky having found a tiny ant queen and let her loose in jade plot. She had mated yea! So her colony grew and they ate or drove out the fly’s. Occasional drop of honey keeps them out of your cabinets. At home entomologist. Lol.

Grow Healthy Roots

Roots need oxygen to grow properly. Hydrogen peroxide can provide that boost while also enhancing growth. Once you plant your seeds or plants, you can spray hydrogen peroxide directly into the soil at the roots, this helps bring your plant more oxygen. When roots have oxygen, they have more room to breathe and are better able to absorb water, both of which they need to grow.

Mix two teaspoons of hydrogen peroxide with one gallon of water and spray it on your garden a couple of times a week.

3. Hydrogen peroxide helps in the development of the root

It helps in the development of the root at any stage of the plant. If the amount of water is increased in a plant then it becomes easily a victim of Rood rot. Hydrogen peroxide rapidly going into the roots of plants, decomposes the soil, and solves its problem. Mix 3% hydrogen peroxide in gallon water, use this mixture as water in the plant once a week, Soak it to the root zone. It helps to increase the oxygen and help to the development of the root zone.

How To Use Hydrogen Peroxide?

  1. Take a paper towel and moisten it with the Hydrogen Peroxide solution. Make sure that you are not soaking the towel.
  2. Place your seeds in the towel, wrapping them completely for 18-24 hours.
  3. Plant your seeds the next day into the pots.

Using Hydrogen Peroxide will shave off germination time from the seeds like corn, peas, cucumber, melons, sunflowers, squash, etc. Also, if you are growing peppers, eggplants, spring flowers, and celery it can cut a lot of time!


How to Make Snake Plants Grow Faster

21 Awesome DIYs to Help You Make Your Own Hanging Garden

15 Eye-Catching Houseplants with Zebra Prints


Can you please provide a botanical study on the effects of peroxide on germination of seeds?

I tried this last year after watching a video.i decided to try it on half of my mature seedlings. and everything I used peroxide on as per your instructions died. It’s a good thing I did not use it on all of my seedlings just half so I lost half of my yield.

Don’t use pure hydrogen Peroxide, dilute 1 ounce of hp in 1 pint of water. I germinate 10yr old seeds this way. Soak in glass of mixture for 12hrs-24hrs, rinse then plant in your medium.

You’re supposed to use it on seeds. Not seedlings.

I dip mine in solution and then plant them instead. I found the roots get tangled in the towel Doing it this way. I found that Dipping them in The solution and planting them worked just as good. I used small cups with holes in the bottom so it’s harder to over water them.

I would not soak seeds like Echinacea in 3% H2O2. Hydrogen Peroxide is pretty reactive on organic tissues. It’s actually not recommended to use in wounds any more because of how much damage it can do. Seeds with hard seed coats can stand 3% H2O2 for limited periods of time. But even for those seeds knicking/cutting the seed corner usually does the job. A safer method for Echinacea germination would be to dilute down to 1/8th (0.00375 % H2O2) dilution and soak for 12-24 hours similar what Andrew mentioned above in his 1/16th dilution. I’ve been growing Echinacea as a hobby since the early 1990s. 60 days cold stratification (in a damp paper towel in the fridge) is also important to cause the chemical changes in the Echinacea seed to get you to germination. I would never use 3% H2O2 on live plants of any age. It is too reactive. It has been used diluted to deal with fungus gnats but it is still risky to the plants.

I have used peroxide mixed with water to water plants at my garden center when plants have been in pots a long time. It definitely perks them and rejuvenates them. I only do this on occasions and when the plants just aren’t looking happy. I also use Epsom salt and water on occasions as well. They work.

Long term fan of huge peroxide use but it’s use on seeds is new to me

Watch the video: Benefits of Hydrogen Peroxide on Plants and stem cuttings

Previous Article

Echeveria 'Green Abalone'

Next Article

Varieties Of Orange Fruit: Learn About Different Types Of Oranges