Hydrogen Peroxide For Plants – What Is It Good For?

The main purpose of using hydrogen peroxide on your plants is to kill off the bacteria that cause disease. If you are looking for ways to get rid of those pesky aphids, spider mites or powdery mildew, then this may not be the best solution for you. However if you want to keep your garden healthy and look after it better, then hydrogen peroxide might just work!

In fact, there are some studies that show that hydrogen peroxide kills off many types of fungi and even certain species of insects. This means that it could be used to treat any type of plant problem including leaf blight, stem rot, brown spot etc.

What You Need To Know About Using Hydrogen Peroxide On Your Plants:

You need to make sure you have enough hydrogen peroxide for your plants. You will need to use a high concentration of hydrogen peroxide so that you don’t end up with excess levels.

It is very important that you do not overdo it and start spraying your plants with hydrogen peroxide all the time. This can cause damage to them.

They should only be sprayed when they are sick or dying from something else first.

You should also not try to use this method on highly alkaline or saline soils. You should also not use it if your plants have been exposed to herbicides or pesticides in the last couple of weeks either.

What Should I Look Out For?

The main thing you need to look out for is making sure that the concentration of the hydrogen peroxide is correct. That said, you should always test it on one of the plants first before spraying everything if it is the first time you have used this.

You will need to check the instructions that come with the hydrogen peroxide you buy because many of them are not as strong as the 3% solution that is normally stated on the bottle. You need to be careful with this stuff because it can burn the plants if the concentration is too high.

How To Use It:

The instructions for using hydrogen peroxide on your plants will normally come with the bottle that you buy. You should always follow the instructions to the letter so that you don’t do more harm than good.

Garden Uses For Hydrogen Peroxide: Will Hydrogen Peroxide Hurt Plants - igrowplants.net

For those of you that have bought the 3% hydrogen peroxide that we suggested, then here are the standard instructions.

You need to mix one part of 3% hydrogen peroxide with ten parts of water. So if you had a bucket that held 2 gallons, you would mix 1 cup of the 3% solution with 10 cups of the water.

Then all you have to do is dip your plants into this mixture so that the roots are covered but no so much that they are floating around in it. You need to leave the plants in the mixture for about 5 minutes and then drain them.

Stick them back into the soil and keep an eye on them to make sure that everything goes back to normal quickly.

What Are The Risks?

As we have already mentioned, 3% hydrogen peroxide can be quite damaging to your plants if you use too much of it. This could even be fatal for some plants!

You should always follow the instructions to the letter when using this stuff otherwise you could end up killing your plants!


Hydrogen peroxide can be a great way of treating leaf blight when used in the right way. It is pretty cheap and easy to get hold of so it could definitely be worth having some around for those unexpected fungal attacks.

As with everything, make sure you test a small portion of one of your plants first before using it on all your other ones.

Also, don’t use if your plants show signs of being affected by an invasive species such as an aphid attack. Instead try one of the other guides we have written here on this site.

Thanks for reading and be sure to check out the rest of our site!

Quick Summary

Garden Uses For Hydrogen Peroxide: Will Hydrogen Peroxide Hurt Plants at igrowplants.net

Search for signs of leaf blight by checking for spots and discoloration.

Spray the affected leaves with a mix of 3% hydrogen peroxide and water.

Make sure you follow the instructions on the bottle as incorrect usage can actually cause more harm than good.

Sources & references used in this article:

Ethylene‐promoted ascorbate peroxidase activity protects plants against hydrogen peroxide, ozone and paraquat by H Mehlhorn – Plant, Cell & Environment, 1990 – Wiley Online Library

Physiological responses of garden cress (L. sativum) to different types of microplastics by S Pignattelli, A Broccoli, M Renzi – Science of the Total Environment, 2020 – Elsevier

Anoxic stress leads to hydrogen peroxide formation in plant cells by OB Blokhina, TV Chirkova… – Journal of Experimental …, 2001 – academic.oup.com

Antibacterial, antioxidant and fibroblast growth stimulation of aqueous extracts of Ficus asperifolia Miq. and Gossypium arboreum L., wound-healing plants of Ghana by K Annan, PJ Houghton – Journal of Ethnopharmacology, 2008 – Elsevier

… of Chromolaena odorata on human dermal fibroblasts and epidermal keratinocytes against hydrogen peroxide and hypoxanthine–xanthine oxidase induced damage by PT Thang, LS Teik, CS Yung – Burns, 2001 – Elsevier

In Vitro evaluation of effects of two ghanaian plants relevant to wound healing by AY Mensah, PJ Houghton, RA Dickson… – … Journal Devoted to …, 2006 – Wiley Online Library

Auxin-like compounds act as protectors against UV-B irradiation in garden pea plants by I Sergiev, D Todorova, E Shopova, Z Katerova… – Botanica, 2017 – content.sciendo.com

The role and the interrelationship of hydrogen peroxide and nitric oxide in the UV-B-induced stomatal closure in broad bean by JM He, H Xu, XP She, XG Song, WM Zhao – Functional Plant Biology, 2005 – CSIRO



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