How To Use Beneficial Nematodes For Indoor Plants

Nick Durante
by Nick Durante
Credit: Shutterstock / Kostikova Natalia

If you have a lot of experience with indoor plants, then you probably have a lot of experience with pests. Whether it be fungus gnats or spider mites, pests quickly spread throughout a home and make it hard to care for indoor plants. That’s why so many gardeners and homeowners want to know how to use beneficial nematodes for indoor plants.

The best way to use beneficial nematodes for indoor plants is to wet the soil and mix the nematodes with water. Water the soil like you typically would as you apply the beneficial nematodes. Avoid doing this in daylight or under UV lights, as ultraviolet rays can kill beneficial nematodes. Before sunrise or after sunset is the best time to do this. 

Beneficial nematodes can target pests in your home for up to 2 weeks, but they live longer than that. More than anything, it’s important to follow the instructions that come with your nematodes. Follow along as we explore how to use beneficial nematodes for indoor plants. 


What Do Beneficial Nematodes Kill?

Beneficial nematodes kill everything from grubs, gnats, and cutworms to weevils, caterpillars, thrips, and beyond. They can kill over 200 pests that would otherwise disrupt your life and home and threaten your houseplants. Many homeowners and plant nurseries use beneficial nematodes to kill larvae before they hatch.


How Long Does It Take Beneficial Nematodes To Kill Fungus Gnats?

It typically takes 1 to 2 days for beneficial nematodes to kill fungus gnats. How long it takes depends on how bad your infestation is. For example, it could take beneficial nematodes up to a week to kill fungus gnats at a large home or plant nursery. 

Beneficial nematodes act quickly, especially in large numbers. Their unique behaviors let them kill a wide variety of pests in short succession. They enter pests, like fungus gnats, through an orifice such as their mouth.

Once inside, the nematode doses the pest with bacteria that poisons their blood and kills them. While it isn’t eventful to watch, the results are quite quick and impressive. 


How To Apply Beneficial Nematodes Indoors

Applying beneficial nematodes to indoor plants is easy, but you must follow precise steps. We have provided a simple guide on how to use beneficial nematodes indoors. However, you must check the instructions that come with your nematodes before applying them. That said, these few simple steps work for most gardeners and homeowners.


Moisten The Soil

Before applying beneficial nematodes, you must moisten the soil. You can do this easily if you spritz the soil, so it’s not too wet. Otherwise, you can lightly water your plants several hours before you apply the nematodes.

Give the soil a few hours to dry out a bit for the best results before you use the nematodes. The top layer of soil should be moist to touch, but not wet. 


Prepare Your Nematodes

When you buy nematodes, the container they come in should have instructions that will typically tell you how to prepare the nematodes before applying them to soil. In most cases, this involves mixing them with water.

How much water you use has to do with how many nematodes you bought. Keep in mind that beneficial nematodes are tiny, so even large quantities, such as 5 million, appear quite small. Some companies suggest mixing 5 million nematodes with 3-4 gallons of water.

However, it’s a good idea to store some of your beneficial nematodes for later. For example, you can mix 1 million nematodes into 1 gallon of water, and then use it to water your plants. However, they don’t last long once opened. Never use more water than the instructions suggest, or else you may not get great results. 


Mind The Sun

Beneficial nematodes are easy to handle, but sunlight is one of its biggest weaknesses. Ultraviolet radiation from the sun can quickly kill them, especially in strong concentrations. That’s why it’s important to consider what time and where you apply the nematodes.

For example, you must be careful if you put beneficial nematodes in the soil of a plant near a sun-facing window. Ideally, you should apply your nematodes early in the morning before the sun rises, or at night at sunset. That way, they will have more time to target and kill pests that harm your indoor plants. 

Otherwise, you can simply close your blinds or cover your windows before you apply the nematodes. It’s also a great idea to turn off grow lights that emit UV rays if you can’t wait until the sun goes down. Luckily, you don’t have to worry about sunlight as much with indoor plants as you would in your outdoor garden. 


Water Your Plants

Once you’ve mixed your beneficial nematodes with water, you can water your plants to apply them. Be careful as you water your plants and aim for the soil. Avoid watering the leaves, especially if they hang over the edge of the pot. 

Otherwise, the nematodes may not land in the soil and will go to waste. Follow your typical watering routine as you apply the nematodes. Make sure you don’t oversaturate the soil, or else the nematodes won’t be as effective.

Now, all that is left to do is to wait for the beneficial nematodes to kill the pests on your indoor plants. You can follow the same process with outdoor plants. However, you must be more careful about sunlight when it comes to outdoor plants. 


How Long Do Beneficial Nematodes Last?

Beneficial nematodes can last for 18 to 24 months once you release them in your home or garden. However, you must be careful when storing beneficial nematodes, as they may only last 2 weeks. That’s especially true if you store your nematodes in a refrigerator and keep the lid sealed.

Never put a container of beneficial nematodes in the refrigerator if you’ve opened it already. While beneficial nematodes can last up to 2 years, you only reap the benefits for 2 weeks in many cases. They become much less active after this time. 


Are Beneficial Nematodes Harmful To Humans?

Beneficial nematodes cannot harm humans, plants, or animals. They don’t target or harm beneficial insects that help plants either. Using beneficial nematodes is one of the easiest ways to rid your home of pests and protect your plants. 


Summing It Up

Moisten the soil before you apply beneficial nematodes, but make sure you don’t get it too wet. Next, you must mix the nematodes with water and water your plants. Avoid doing this during broad daylight or under UV lights, as it can kill nematodes. Finally, wait 1-2 weeks while the beneficial nematodes kill the pests on your indoor plants. 


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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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