By Erin Marissa Russell
Can you really use hydrogen peroxide on houseplants? Yes, and we’ll explain all the ways you can make use of hydrogen peroxide in an indoor garden. All of these instructions are for 3 percent hydrogen peroxide, which is what you can find at the store. Keep reading to learn about all the ways hydrogen peroxide can help keep your houseplants healthy.
If your houseplant has root rot, you may be able to tell by an unpleasant smell or the presence of gnats. But if you can’t see these signs and still suspect root rot, you may need to examine the roots of the plant to find out for sure.
Gently lift the plant out of the soil, taking care not to harm the roots. Do you see areas of the roots that are slimy or discolored to brown or black instead of the pale color of healthy roots? If so, you’re dealing with root rot.
Of course, like any treatment, hydrogen peroxide can’t make the dead, slimy, or discolored portions of your houseplants’ roots come back to life. But hydrogen peroxide can help keep the disease from spreading and prevent your plant from getting worse. Here’s what to do.
Start by cleaning and disinfecting a pair of gardening shears. Then cut away any parts of the roots that have turned dark or slimy. Shake the roots gently as you work to get the soil off of them.
Next, apply 3 percent hydrogen peroxide to the roots of the plant, either by spraying or pouring it on. Find your plant a new container and fill it with fresh, clean soil. Moisten the soil a bit, then plant your houseplant in it. Discard the old soil, but do not put it in the compost heap. You can use the old container again once it has been cleaned and disinfected.
To help keep root rot from coming back after you’ve treated with hydrogen peroxide, be careful not to overwater your plant. There’s a simple test to let you know whether it’s time to water one of your houseplants yet. Simply insert a finger into the soil to a depth of about one inch. If it feels moist or clings to your finger, it isn’t yet time to water your houseplant. Wait until the soil feels dry and does not cling to your skin.
You probably already know that hydrogen peroxide is a great disinfectant from using it in medical or household applications. Did you know that you can use hydrogen peroxide to disinfect soil before using it in your garden? It may not have ever occurred to you to disinfect soil before use. Even storebought potting soil can carry bacteria or fungus that can be harmful to your garden. Disinfecting soil before you use it means you won’t need to worry about passing these pathogens along to your houseplant collection.
Start by adding your potting soil to a clean, sterilized container. (See the next section if you aren’t sure how to sterilize a container.) Then sprinkle the soil with a tablespoon of hydrogen peroxide diluted in eight ounces of water. Water the soil two or three times over the course of a week to get the solution mixed down into the soil. Now your disinfected soil is ready to use.
If you aren’t already cleaning and disinfecting your gardening tools and supplies, you should start. Tools that haven’t been cleaned or disinfected can spread plant disease throughout your houseplant collection. You should clean and disinfect any tool or container before using it in the garden.
Create a spray out of one teaspoon hydrogen peroxide and eight ounces of water. If you’re dealing with an active disease in the garden, you can increase the solution to one tablespoon per eight ounces of water. Simply spraying your tools and containers down with this solution will clean and disinfect them. Then dry your tools well so they won’t rust.
Using hydrogen peroxide on your seeds will disinfect them, making sure they don’t bring bacteria along with them into your garden. Hydrogen peroxide can also help speed up how quickly your seeds sprout.
To disinfect seeds, pour three percent hydrogen peroxide into a container that is small and water-tight. Soak your seeds in this solution for about four hours. Then rinse the seeds well in clear running water, and move them to paper towels to dry.
Hydrogen peroxide helps roots by aerating the soil so the plant’s roots have more room to spread out in their search for moisture and nutrients. Hydrogen peroxide will also help prevent plant disease like fungus or root rot. You don’t need to wait until your plants are already sick. You can use hydrogen peroxide on them to keep them thriving.
Use a solution of one teaspoon 3 percent hydrogen peroxide in eight ounces of water. (You may need more than eight ounces if you’re going to be treating a lot of plants.) Use this solution every other time you give your plants water.
Hydrogen peroxide can repel those insects that take up residence in your garden. Keep in mind that this treatment will repel beneficial pollinators as much as it will pest insects. Mix one tablespoon of 3 percent hydrogen peroxide into a gallon of water. For easy application, move the solution into a spray bottle.
Spray your plants’ foliage once per week if you’re using hydrogen peroxide as a preventive. If your garden already has bugs, you may need to use hydrogen peroxide two or three times per week to get rid of them. You should also apply the spray after it rains, as the showers will wash off any spray you have applied.
As you can see, there are lots of reasons to get hydrogen peroxide involved in caring for your houseplants. As a preventive, a seed soak, or an insect repellent, you can use a teaspoon of hydrogen peroxide in eight ounces of water. 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. Store hydrogen peroxide solutions in a dark-colored container, and make sure the lid is airtight. The place where you store hydrogen peroxide solutions should be cool, dark, and well-ventilated.