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).
Use a spray bottle to thoroughly soak the infected plants. Make sure to get the undersides of the leaves. Spray once a week or after it rains. Hydrogen peroxide both treats and further prevents pest infestation.
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.
Hydrogen peroxide can help to control fungal growth and fungal infection, such as root rot, by preventing the growth of fungi. It can also help kill fungus and bacteria on plant roots.
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).
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%.
If you use a higher concentration of hydrogen peroxide on the foliage of the plant you run the risk of burning it. You could burn the roots, but since it's necessary to kill the root rot-causing bacteria, it's a risk worth taking.
Using a level 3 hydrogen peroxide concentration, thoroughly dilute 15mL (1 tablespoon) of hydrogen peroxide to 240mL (1 cup) of water. If you kept your plant in its old potting mix, wait for the soil to dry and use this treatment by drenching the soil as if you're watering the plant.
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 up a solution of 1 part pure hydrogen peroxide (with no additives) to 4-5 parts water. Mix well and water the plant, making sure to thoroughly drench all parts of the soil. The hydrogen peroxide will fizz; that's what kills the larvae and the eggs. Repeat in 2 weeks for a larger pot; in 7-10 days for a small pot.
Dilute 2.5ml hydrogen peroxide and 3 drops of neem oil to a 7500ml spray bottle to spray leaves. 2.5ml ammonia and 2.5ml neem oil once a week for pest control in spray bottle.
Double Up Your Protection with Isopropyl Alcohol
With the peroxide helping to keep your plants healthy and free of bacteria, you now need to prevent contamination of the tools and equipment you use to plant, trim, and water your crops.
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!
Walgreens Hydrogen Peroxide 3% 16.0oz | Walgreens.
Soak growing medium such as sand or soil in a 3-6% solution of hydrogen peroxide. Allow the medium to sit in the mixture overnight. Turn the mixture once or twice to circulate throughout the medium. This can kill bacteria, mold or mildew, worms and their eggs.
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.
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.
For a foliar spray to perk up growing plants, use 1 pint of 35% hydrogen peroxide (or 11 pints of 3% hydrogen peroxide) in 20 gallons of water to spray one acre. water (equal to about 6 gallons of 3% hydrogen peroxide [or 5 pints of 35% hydrogen peroxide] and 6 gallons of molasses per 100 gallons water).
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.