For planted seedlings: Spray with H2O2 solution of 1 part H2O2 3% to 32 parts water (eg: around 30mls per 1 litre - measuring cup recommended). For established plants: Mix 1:1 ratio of 3% H2O2 and water (eg: 1 cup of each). Bottom or top water as usual (water soil only, do not pour on leaves).
It also breaks down into the soil and releases extra oxygen that helps the plant grow new, healthy roots. Before you use hydrogen peroxide on your plants, you'll need to dilute it. Mix one part of 3 percent hydrogen peroxide with two parts water in a watering can or spray bottle.
For misting Indoor plants mix 1 tsp./ cup of water. This improves aeration to your plant and deters fungus on leaves and soil. The ratio here is one part 3% hydrogen peroxide to 48 parts water. To help kill pests on the plant leaves like Aphids, spider mites and other sapsuckers use the misting solution above.
To use hydrogen peroxide as a soil drench, mix 1 part hydrogen peroxide with 2 parts water. Pour the mixture around the base of the plant. Be sure to avoid getting any on the leaves, as this can damage them.
I would only use it as often as is necessary, but wouldn't recommend using it more than twice a week. What is this? If I'm treating a plant for pests or root rot, I'll either spray the leaves or the soil with a hydrogen peroxide solution once a week until the issue has been resolved.
If you are treating a sick plant or one infested with insects, use a slightly stronger mixture of one tablespoon of hydrogen peroxide in eight ounces of water. Don't use hydrogen peroxide on your plants more frequently than twice each week. If you make more than you need, you can store it.
As with all things H202, the amount and concentration of peroxide you use matters. The right amount will benefit your plants, and too much will harm them or even kill them.
Under aerobic soil metabolism conditions, hydrogen peroxide degrades with a half-life of ca. 1.4 hours in diluted test solutions. This half-life value was extrapolated to ca. 7 hours for concentrated test solutions.
Hydrogen peroxide kills root rot-causing bacteria and fungi and restores the oxygen balance in the soil which boosts your plants' growth and health. Due to its chemical similarity to water, hydrogen peroxide is one of the safest chemicals you can use in the garden to combat root rot.
After you've cut off any dead roots, we recommend soaking them in an 80:20 solution of water to hydrogen peroxide. Five minutes or so should be sufficient.
If you see signs of houseplant bugs like buzzing gnats or green algae growing on your potting soil, you may need to treat the problem with hydrogen peroxide. Hydrogen peroxide is often a great choice because it is a common household supply and effective at treating unwanted guests.
Hydrogen peroxide reacts very fast. It will than disintegrate into hydrogen and water, without the formation of byproducts. This increases the amount of oxygen in water.
Treat the soil.
Use 1-2 tablespoons of hydrogen peroxide per cup of water, and mix enough to saturate the entire root ball. Mix well, then apply to the soil. Hydrogen peroxide is root safe though it can look a little scary, because it will begin to bubble up when poured in. This is normal!
Mix 50ml of Hydrogen Peroxide 3% – Oxygen PlusTM per 4 litres of water (60:1 ratio of water to H2O2). Soak the roots into this solution for about 6 hours. Replant in a new container with clean, fresh potting mix.
Apart from being more mindful of how often and how much water you give your plants and plant roots, you can also use a mixture of 3 percent hydrogen peroxide concentration mixed in 1 quart of water once a week to encourage healthy root growth in your plants' roots or treat the spread of root rot and root decay.
Hydrogen peroxide, well known as an ingredient in disinfectant products, is now also approved for controlling microbial pests on crops growing indoors and outdoors, and on certain crops after harvest. This active ingredient prevents and controls bacteria and fungi that cause serious plant diseases.
Mix one part 3% percent hydrogen peroxide with two parts water and carefully pour it over the root of your plant system with a watering can or spray bottle. This will kill off the bacteria which cause root rot.
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.
When peroxide is mixed with soil it will react with living microbes as well as dead organic matter. In fact, an older method for measuring the amount of organic matter in soil used peroxide as the main reagent. During this reaction oxygen is produced and can be observed as bubbles.
Make an apple cider vinegar trap
Stir in a few drops of liquid dish soap and place the trap near the base of the affected plant or on top of the soil. You will need to refresh these traps every few days as they attract and kill the adult fungus gnats.
Hydrogen peroxide both treats and further prevents pest infestation. This weaker solution will prevent damage to the leaves and is effective as a general insecticide.
Don't use hydrogen peroxide on wounds
“Hydrogen peroxide has fallen out of favor as a wound cleanser,” Dr. Beers says. “Studies have found that it irritates the skin. It may prevent the wound from healing, doing more harm than good.”