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Ways to Use Hydrogen Peroxide for Growing Cannabis 

Added 10 August 2023

As a cannabis grower, you are probably always trying to find ways of dealing with your plant’s problems and pests while encouraging optimal growth. And in this journey, you can use a lot of stuff that can improve growth. 

However, a lot of these are synthetic chemicals, so what happens if you don’t want to use them to prevent them from harming your soil, plant, and the environment in the long run?

A natural approach is the best course of action when growing cannabis, whether it is to give your plant a nutrient boost or deal with a pest problem. Such an approach ensures you keep your garden’s carbon footprint minimal while protecting your plant from the harsh side effects of synthetic products. 

And during your research for the best organic aid for cannabis, you’ll likely come across hydrogen peroxide. This is natural and eco-friendly (when used properly), and it can help you boost your plant’s growth, deal with its problems, and keep harmful pests and pathogens at bay. 

However, hydrogen peroxide isn’t a magical cure that you can use whenever you want; you must use it properly and with care if you want to extract its benefits without harming the plant or the environment. But do it well and this compound can serve many purposes in your garden. 

Learn what hydrogen peroxide is and how it helps cannabis plants, and some of the best ways of using it in your cannabis grow room. 

What is Hydrogen Peroxide?

What is Hydrogen Peroxide?

Hydrogen peroxide is a naturally occurring chemical, and it is very similar to water at a molecular level since its formula is H2O2 — it has one extra atom of oxygen than water. In its purest form, it is pale blue, but you’ll rarely come across this; usually, it is diluted and will appear like water but more viscous. 

You’d be surprised at the uses of this water-like chemical, though. It is used as a home remedy for cuts and scrapes since it is antiseptic and is also used as an oxidizer. On the other hand of the spectrum, highly concentrated hydrogen peroxide is used as rocket fuel

In the midst of all these uses, you can also use it in your cannabis garden for various purposes like keeping pests at bay, tools clean, and the soil airy. More on this later. 

How is Hydrogen Peroxide Produced?

How is Hydrogen Peroxide Produced?

Yes, hydrogen peroxide is a naturally occurring compound, but there’s not enough of it to be used industrially or even for gardening around the world. So, this compound must be produced synthetically in a lab, but don’t worry, it still retains all the qualities of natural hydrogen peroxide. Let’s take a look at how it is produced. 

In 1799, Alexander von Humboldt created barium peroxide, one of the first synthetic peroxides ever made. Later in 1818, another scientist, Louis-Jacques Thenard found that barium peroxide could be used to create oxygenated water, i.e., water with an extra oxygen atom, which later came to be known as hydrogen peroxide

By the end of the 19th century, scientists had discovered a better way to produce hydrogen peroxide with the help of hydrochloric acid and sulfuric acid. However, hydrogen peroxide is now usually produced through the anthraquinone process. This process was patented back in 1939 and is by far the most economical and efficient way to manufacture this compound. 

Another thing to note is that hydrogen peroxide is unstable and will decompose when exposed to light. So, it is usually kept in storage with a stabilizer and you’ll always find it in a dark-colored bottle that does not let light pass. 

What are the Uses of Hydrogen Peroxide for Growing Cannabis?

What are the Uses of Hydrogen Peroxide for Growing Cannabis?

Hydrogen peroxide is an organic compound that has various benefits for cannabis growers, and here are some of the ways it can benefit your cannabis cultivation. Below are the best uses of hydrogen peroxide for cannabis plants. 

1. Improve Aeration in Poorly Aerated Soil 

While growing cannabis, the type of soil you use dictates how the plant grows. For example, the more airy the soil, the easier it will be for the roots to expand, and if the soil is compacted or dense, the roots may not get enough oxygen to breathe well. So, the airiness of the soil is related to your plant’s health, root development, and even nutrient uptake. 

So, if you’ve gotten soil that is not so airy or has compacted over time, you can use hydrogen peroxide to increase the aeration of the soil. Essentially, this compound can act as an oxidant that increases the oxygen levels within the substrate. When it reacts with water, it produces oxygen, which reduces compaction in the medium, allowing the roots to breathe better.

The same oxygen that is produced when hydrogen peroxide reacts with water also has other benefits. For example, it allows the roots to absorb nutrients more easily, leading to much better plant growth, and it also encourages the growth of beneficial microbes within the soil, which is always a benefit for plants. 

If you want to use hydrogen peroxide to aerate the soil, you need to mix around a pint of food-grade hydrogen peroxide in a gallon of water and irrigate your plant with this water once a week. 

2. Improve Hydroponic Cannabis Growth 

Hydrogen peroxide can also help you improve the results of your hydroponic (or aquaponic) cannabis system. This is because hydroponic cannabis plants rely heavily on water and do not use soil at all. While these closed-loop systems are effective and eco-friendly, they come with a few downsides. 

Hydrogen peroxide helps solve some of these downsides entirely. For example, it can help keep your water oxygenated so your roots don’t have to struggle for oxygen. It can also keep the water clean, prevent fungal and bacterial infections on the roots, and much more. Thus, it’s best you do enough research before using hydrogen peroxide in your hydroponic setup for good results. 

3. Disinfect the Growing Medium

If your cannabis plant is facing growth problems due to an unhealthy growing medium or you want to recycle the growing medium for the next batch of plants, you can use hydrogen peroxide to disinfect it, too. Hydrogen peroxide has antiseptic and anti-microbial properties, so you can drench the growing medium in a dilute hydrogen peroxide solution to disinfect it from any harmful pathogens. 

4. Keep Nasty Pests at Bay

Pests are some of the biggest enemies of cannabis plants, and they come in all shapes and sizes. Some pests are simply annoying to have around your plant whereas others can cause significant damage to your plant and even potentially kill it. So, it is crucial that you keep such pests at bay when growing cannabis plants. 

Here, you can use hydrogen peroxide to prevent pests by spraying down your plant with a diluted solution. Generally, hydrogen peroxide works against common cannabis pests like aphids and it can also kill eggs on contact. 

Hydrogen peroxide is safer and better than other synthetic pesticides since it does not harm the plant or you, but it may sometimes repel beneficial pests that you want to be close to your plant. So, only use this solution if you don’t have beneficial insects in your garden. 

5. Treat Root Rot or Slimy Roots

Root rot is a common problem that occurs in hydroponic cannabis plants, where the roots develop slimy fungal growth. This infection can prevent the roots from absorbing nutrients and oxygen from the growing medium and can eventually kill the plant by starvation. And getting rid of the phytophthora root rot in the medium is difficult. 

So, to treat root rot in your cannabis plant, you need to act quickly and one of the best remedies you can use is hydrogen peroxide. Hydrogen peroxide is excellent at killing fungal spores. Mix 3% hydrogen peroxide with water in a 1:2 ratio and spray down the roots of your plant with the solution. 

6. Treat Other Bacterial or Fungal Infections

Root rot isn’t the only type of fungal infection your cannabis plant may face; your cannabis plant can face many other types of bacterial and fungal infections, especially if you live in a warmer region or mess up the relative humidity in the grow room. And all of these can be potentially deadly for your plant. 

Fortunately, hydrogen peroxide can help fix most of these fungal and bacterial infections on cannabis, too. You can use hydrogen peroxide as a foliar spray to treat problems like fungal diseases, powdery mold, and mildew, and eliminate bad bacteria from the plant. And you can use it as a soil drench to clean the substrate. 

Do note that if you are using hydrogen peroxide as a drench, extra radical oxygen can deplete the medium of beneficial bacteria and fungi, too. So, only use hydrogen peroxide as a soil drench when other solutions have failed; even though the negative effect of this compound is short-lived, it’s best to avoid such issues when growing cannabis. 

7. Prep Seeds Before Germination with H2O2

Germinating seeds is a crucial step as it’s the start of your plant’s life, and if something goes wrong here, the plant can carry the wound throughout its life cycle. If you’ve purchased seeds from a reputable seed bank or using your own seeds, you shouldn’t have any problem, but still, it’s always better to ensure your seeds are free of any pathogens. 

This is where hydrogen peroxide can help you. Simply soak your cannabis seeds in a hydrogen peroxide solution to eliminate any pathogens; many growers also suggest that soaking the seeds in this solution can even improve the germination rate of the seeds. So, try for yourself and find out the truth!

8. Treat Water 

Many cannabis growers like to treat their water before giving it to their plants, and one of the common ways of treating water is using bleach or other chemicals. However, these chemicals end up doing more harm than good since they are not good for the plant as well as the environment. 

Here, hydrogen peroxide can come in handy to keep your water free of pathogens and safe to use on your cannabis plants, whether you are harvesting rainwater or using tap water. 

But before you use hydrogen peroxide, you should consider using other alternatives that are much better, like charcoal filters, sand filters, phytoremediation, or UV sterilization. These methods are more effective and safe, so only choose hydrogen peroxide when you’re out of options and don’t want to use chemicals. 

9. Disinfect Your Gardening Tools

Hydrogen peroxide is an excellent disinfectant, so you can even use it to disinfect your gardening tools like pruning scissors, pots, containers, hydroponic components, and much more. Ideally, you want to use diluted hydrogen peroxide to disinfect your tools after every use and while dealing with a disease outbreak in your cannabis garden. 

10. Wash Your Buds with Hydrogen Peroxide 

Many growers prefer washing their buds with hydrogen peroxide after harvest to eliminate any invisible mold, fungi, or pathogens that may otherwise risk the harvest during the curing and drying phase. 

Here, you need to use a 3% hydrogen peroxide solution and dip your cannabis buds gently in it for half a minute. Don’t forget to move them back and forth gently. Then, place the buds on paper towels to remove excess water from them; you can even place them in a warmer space for a short time. Then, you can continue the usual drying process. 

11. Nutrient Availability

Hydrogen peroxide can help cannabis plants derive nutrition by breaking down some organic compounds that are found in soil. This can possibly boost nutrient uptake and increase plant growth.

Here’s how hydrogen peroxide can help when it comes to nutrients:

Decomposition of organic matter: Dead plant material typically contains carbon and other nutrients. Once they decompose, they release a variety of nutrients such as nitrogen, phosphorus, and potassium back right into the soil. Hydrogen peroxide can help by accelerating the process of decomposition as it tends to break down the matter into several smaller forms, making it easier for the plants to absorb them. 

Iron Availability: The availability of iron can be an issue in alkaline soils that can possibly occur when other ions bind with iron. Iron chelates, the organic molecules that maintain the solubility of iron can help cannabis plants absorb iron in a better manner. Hydrogen peroxide can potentially help by breaking the chelates and releasing iron ions. 

Phosphorus Release: Phosphorus is typically present in the soil in various forms although some of them aren’t available to plants easily. Organic phosphates, for example, call for microbial activity to convert them to a form that’s available to plants. Again, hydrogen peroxide can help by breaking these compounds slowly and releasing phosphorus ions the plants can absorb. 

Micronutrient Release: Micronutrients are as important as macronutrients to help plants grow healthy. However, the plants need very little micronutrients to grow well. These elements are natural particles in the soil but aren’t readily available to plants. Hydrogen peroxide helps by breaking down these natural substances and helps the plants absorb them better. 

How to Use Hydrogen Peroxide on Cannabis Plants?

How to Use Hydrogen Peroxide on Cannabis Plants?

Using hydrogen peroxide on cannabis plants is fairly easy, but there are a few things you must keep in mind. The first is the method of your usage. Let’s take a look at the two ways you can use hydrogen peroxide on your cannabis plants. 

Two Ways of Using Hydrogen Peroxide on Cannabis 

If you want to use hydrogen peroxide on your cannabis plant, here are some things to keep in mind:

Prepare the right concentration: You’ll find hydrogen peroxide easily in drug stores and gardening stores. However, you’ll have to purchase a concentration that is safe for plants. Typically a 3% solution is considered safe, so you can go ahead for purchase it. You’ll have to dilute it further to use on the roots. So, for instance, use 30 ml of 3% H202 in 1000 ml or a liter of water. You can use an even more diluted solution for foliar spray. 

After using the solution, check your plants closely for any adverse reactions. As mentioned already, while hydrogen peroxide can have advantages it can damage plants if you use it improperly. If you see any negative indications, stop using it immediately. Lastly, the frequency of application will depend on the specific needs of your plants and the issues you want to address. 

You can use H202 in one of two ways, which are as follows:

1. Foliar Spray 

The most common method of hydrogen peroxide use is foliar spray, especially when you’re dealing with fungi, pests, or bacteria. If you want to use hydrogen peroxide as a foliar spray, the ideal way to prepare the solution is to mix a tablespoon of 3% hydrogen peroxide in a cup of distilled water. 

To use it on your plant, use a fine mister and ensure you fully cover the leaves or affected areas for the best results. And when you’re done, store the solution in a dark container that does not let light in. 

2. Drench or Watering Solution 

The second method of using hydrogen peroxide is using it as a soil drench, which is ideal for eliminating pests or root rot from the soil. For this, you can use the same ratio as suggested for foliar spray and water your plant normally with the mixture. If you’re dealing with root rot, a single application of hydrogen peroxide should be enough but you’ll have to water the plant with it twice a week to eliminate the pests completely. 

Some Things to Keep in Mind While Using Hydrogen Peroxide 

Hydrogen peroxide is a beneficial compound but only when used properly; use it the wrong way and it can do more harm than good and it can even pose a risk to your cannabis plants. Remember not to use too much or you’ll risk harming the plants. In addition, conduct a patch test on just a few leaves if you’re not sure about the dilution. So, here are some things to keep in mind when using hydrogen peroxide. 

1. It Can Damage Beneficial Microbes 

Hydrogen peroxide is a terrific disinfectant because it kills pathogens on contact, but it doesn’t differentiate. So, it can also damage the healthy microbe life in your soil or growing medium in the long run. This can be an issue, especially if you’re growing in soil, so only use hydrogen peroxide keeping this in mind. 

2. It Doesn’t Fix the Root of the Problem 

Hydrogen peroxide is a quick solution to many problems but it’s only a temporary one and not a final one. It does not fix what’s causing the problem. For example, if your plant is suffering from root rot, it will not fix what’s causing root rot, only remove the rot from the roots, which can develop again if you don’t fix the cause. 

So, hydrogen peroxide should be treated as a band-aid solution for when other things haven’t worked and you’re still trying to fix the main problem, not as a fire-and-forget solution. 

3. Store in a Dark Place

Hydrogen peroxide degrades easily when it is exposed to light, so always store it in a cool dark place away from any source of light. Your best bet is to use airtight containers that are dark-colored, so they don’t allow any light to get to the solution. 

4. Never Heat the Solution 

Hydrogen peroxide is already an unstable compound, so do not ever heat it. It can explode if you heat it beyond a certain point. So, it’s best to handle this compound with immense respect and care and ensure there are no open flames nearby when using it. 

5. Always Wear Rubber Gloves 

Hydrogen peroxide is only safe to use in diluted concentrations. As mentioned above, concentrated hydrogen peroxide solution can be extremely dangerous — it’s literally rocket fuel that can combust quickly. Plus, higher concentrations can even damage the soil ecosystem and kill your plants. 

At higher concentrations, hydrogen peroxide can cause irritation to your skin, and, in severe cases, it can even cause burns. So, when it is not diluted in water, always wear rubber gloves and handle the solution with precaution. Here, regular gardening gloves won’t work to protect you since they’re not waterproof. 

If it does get on your skin, rinse it immediately with water and visit a physician if you notice any kind of side effects of it. And it goes without saying, keep this solution away from the reach of your children and pets. 

Is Hydrogen Peroxide Eco-Friendly?

Is Hydrogen Peroxide Eco-Friendly?

In the above sections, it’s mentioned that hydrogen peroxide is organic but you’ll find a lot of conflicting information on this aspect of the compound. The apprehensions about this compound aren’t wrong, either. Hydrogen peroxide’s eco-friendly properties depend on its concentration and quantity. 

Hydrogen peroxide is a naturally occurring compound that quickly degrades into oxygen and water, making it much more eco-friendly than other alternatives that can be polluting or harmful. However, if you use highly concentrated hydrogen peroxide, it can be harmful to you and the environment. 

Plus, modern hydrogen peroxide is manufactured in labs, and the process is not usually eco-friendly. For example, many manufacturers use palladium catalysts to produce hydrogen peroxide, which is difficult to obtain and non-renewable. Check out this source to know more about the environmental concerns of H2O2

However, you can rest assured that it is safe and organic in diluted concentrations, as it's approved for organic agriculture. It is non-toxic and 100% biodegradable, and doesn’t produce any harmful byproducts during or after use. 

Summary: Ways to Use Hydrogen Peroxide for Growing Cannabis 

Hydrogen peroxide was first discovered in 1799, and over the years, we have figured out many ways of producing this naturally occurring compound in labs. And with the production methods, experts from various fields found innovative uses for this solution, from medicine to rocket science, hydrogen peroxide is common in many industries. 

Gardening is no different. Hydrogen peroxide, or H2O2, serves many functions in a cannabis garden, such as the following:

  • It eliminates harmful pests, fungi, and bacteria 
  • It can disinfect gardening tools and hydroponic systems 
  • It prevents salt buildup in irrigation systems 
  • It removes chlorine from the nutrient solution 
  • It can disinfect the growing medium 
  • It can cure issues like root rot, slimy roots, mold, etc. 
  • It improves the aeration of the soil 
  • It even stimulates leaf growth 

It has many benefits and the best part is that this solution is completely eco-friendly and safe (in dilute concentrations). So, there’s no reason to not use this, but when you do, make sure you take the right precautions to use this rocket fuel in your cannabis garden. 

Always wear rubber gloves when handling concentrated hydrogen peroxide and keep the solution away from kids and pets. Also, store the solution in a cool dry place away from any source of heat. 



washing buds - gets dirt off. if you think the methods out there for bud washing disinfect your buds, you are lying to yourselves. the youtube video by what's his name is misleading and spreads false information. latino name.. i can't recall off the top of my head... long grey hair at this point, glasses.. a big name i'm brain-farting. your buds won't be disinfected. you'll still be smoking bits of rot and mold if you do it.