How To Use Nematodes To Control Garden Pests!

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How To Use Nematodes To Control Garden Pests
How To Use Nematodes To Control Garden Pests! –

Gardening is one of the most relaxing and rewarding hobbies to have. When you take care of your garden properly and with care, it blooms beautifully. However, all gardeners must watch out for pests out there that may cause significant damage to your garden. If so, then nematodes might be the right solution for you. Then how to use nematodes to control garden pests?

Nematodes can be applied easily to any garden. They come in a bag, and all you have to do is mix the bag’s instructed amount of water in them, pouring it into areas where you think the pests populate the most.

Below, we’ll cover in detail how and when to use nematodes. Furthermore, there are several types of nematodes to choose from. So, before purchasing and applying nematodes to your garden, make sure you identify the insects you have pestering your space. Then, you can purchase and apply them to your garden.

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What Are Beneficial Nematodes?

Nematodes are the best way for gardeners interested in using biological pests control. Beneficial nematodes are effective and relatively easy to kill pests without using harmful toxic chemicals.

If you are an organic gardener, beneficial nematodes are biological – not chemical – pest control. And, unlike a chemical pesticide spray, which may drift off target, nematodes are specific to the host pest and help preserve other wildlife.

Nematodes are tiny, colorless, cylindrical roundworms that grow naturally in soils around the world. 

The nematodes enter the insect host through body openings, multiply within the host, and release a symbiotic bacterium whose toxin kills the pests. The nematode then eats the host. 

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When to Use Nematodes?

You should apply nematodes in the morning or evening when the soil temperature is between 42°F – 95°F and the sun is not as bright (UV rays harm nematodes) because they remain effective up to 95°F. 

Also, the timing of applications during the year will depend on the type of pests. Make a follow-up application (second application) around 1-2 weeks after the initial application during the fall months if pests invade your garden.

If the pest continues to invade your garden, use nematodes every 7-10 days or until the infestation subsides.

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How to Use Nematodes

When you purchase nematodes in a store or online, they will usually come in a small bag with a paste. The best way to purchase nematodes is to use them immediately. 

However, if you do not want to use them immediately, you can store them in a cold-temperature area, such as a fridge, for up to several weeks. Just keep in mind not to freeze the nematodes but only keep them cool.

Here’s how to use nematodes:

  • Step 1: Before using the nematodes, ensure that the soil you are applying to is moist and temperature for at least a week or two. The temperature of the soil should at least be above 5°C throughout the day and night. This will ensure that the nematodes remain active after applying their property.
  • Step 2: When you are ready to use them, mix the paste inside the bag with a small amount of water or how much water is indicated on the bag. This will make the paste muddier in texture. 
  • Step 3: Once the mixture begins to liquefy, add more water and keep stirring simultaneously
  • Step 4: After mixing the water with the nematodes and the paste, place them in a bucket or a watering can. When using a watering can, ensure you use a coarse rose, as these are big enough for the nematodes to go through. Otherwise, the nematodes will get stuck in the holes while trying to disperse them.

Aside from the aforementioned steps above, you have to use nematodes in the right conditions. Ensure that there are low light conditions when applying the nematodes, as nematodes are sensitive to light.

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How Long Does It Take Usually for Nematodes to Work?

After application, it usually takes around 2 to 4 weeks for nematodes to work. Beneficial nematodes require time to parasitize and kill their host entirely, then move on to the next host. Most importantly, nematodes kill pests from the inside out.

Contrary to chemical pesticides, you will not see dead insect bodies. Instead, adult pest populations should slowly and gradually decrease as the nematodes kill infected life stages.

How Do Nematodes Work?

Nematodes travel via water between soil particles and identify their prey by monitoring changes in temperature variation and carbon dioxide levels and sometimes by excrement trails.

Once nematodes identify their prey, it enters the chosen insect through a natural opening in its body, such as the mouth, anus, or spiracles (holes used to exhale carbon dioxide).

They release a strain of bacteria that resides within their digestive system. These bacteria will quickly multiply and kill the insect within 24 to 48 hours.

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How Frequent Should You Use Nematodes?

The only time that you should be using nematodes is whenever garden-destructing larvae or grubs are starting to occur. For the most part, these larvae and grubs usually occur between Spring and Autumn, when they feed the most on plant roots. 

It will be initially difficult to know when to use them as the damage is done below the soil, and you won’t know there is a problem until the damage has been done. 

However, you can always look for signs of adult insect species that are garden damagers. Usually, if you find a couple of these adult insects, their eggs won’t be far behind and will hatch soon. If so, then let the nematodes loose!

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Will Fertilizer Kill Nematodes?

Because of its high nitrogen content, fertilizers can limit nematode effectiveness. Generally, manufacturers recommend that fertilizers not be used two weeks before and after nematode application. Check the package instructions.

The general recommendation is to wait at least one month after applying a non-slow-release fertilizer, as a high concentration of standard fertilizers can be detrimental to nematodes.

See also: Are Fertilizers And Plant Food The Really Same: Here’s The Truth!

Best Nematodes for Specific Types of Pests

There are several types of nematodes to choose from, as some target specific types of larvae and grubs. Therefore, you need to identify what the problem is and which nematodes you should purchase.

Below are a few examples of nematodes available in the market today:

Nematode Steinernema Carpocapsae 

This type of nematode is a perfect ant hunter, as it will ambush ants when they pass them. The best time to use the Nematode Steinernema Carpocapsae is between April to September.

The nematodes will automatically poison the ants but not kill them. When the ant retreats back to its nest, that poisoned and will weaken the rest of the colony. Eventually, the poison will get to every ant in the colony, including the queen. 

Nematode Heterorhabditis Bacteriophora

This particular nematode is most effective against Chafer grubs. These nematodes are particularly effective because they are insect parasitic, capable of infecting and controlling the Chafer grubs.

One indicator that you may have Chafer grubs is that animals, such as birds, foxes, and badgers, might be digging around for these grubs. When they are hunting them, your lawn may look like it has been dug up in patches.

Nematodes Steinernema Feltiae

The Nematodes Steinernema Feltiae are specifically effective against Leather Jackets, which are larvae commonly found underground and are known to attack the roots of your grass lawn after incubating for two weeks.

Luckily, the Nematodes Steinernema Feltiae can control these Leather Jacket larvae before they start attacking the roots. 

When the Leather Jacket larvae are incubating in the soil, the best time to apply the Nematodes Steinernema Feltiae is in Autumn. These larvae usually begin feeding between Winter and Spring, so it is best to apply them in Autumn, right before Winter kicks in.

Nematode Steinernema Kraussei 

The Nematode Steinernema Kraussei specifically targets the Vine Weevil larvae. Unlike other nematodes, this one is active in low-temperature soil (5°C). This means that you can start applying the nematodes as early as March, giving more effective against the Vine Weevil larvae. 

Similar to the Leather Jacket larvae, the Vine Weevil larvae also begin feeding between Autumn to Spring. Aside from that, the larvae are also common from July to October. However, they can still be present throughout the year as well. When left unchecked, the Vine Weevil larvae can cause significant damage to plant roots. 

Nemasys Natural Fruit and Vegetation Protection Pest Control

The Nemasys Natural Fruit and Veg Protection Pest Control is a generic type of nematode particularly effective against common pests, such as fruit flies, onion flies, a variety of caterpillars, and codling moths. 

Nematodes Heterorhabditis Indica

The Nematodes Heterorhabditis Indica targets Small Hive Beetle ((Aethina tumida) in the soil and kills them within 24-48 hours. 

In addition, The Nematodes Heterorhabditis Indica is effective against: 

  • Fall armyworm 
  • Japanese Beetles
  • Fungus gnat 
  • Root weevil 
  • Indianmeal moth 
  • White grubs 
  • Western flower thrips 

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What Pest Is The Nematode Used to Control?

The table below contains a list of pests controlled by beneficial nematodes.

Steinernema carpocapsaeSteinernema feltiaeHeterorhabditis bacteriophora
Pest controlled – Armyworm
– Lesser Peach Tree Borer
– Large Pine Weevil
– Leafminers
– Mint Flea Beetle
– Mint Root Borer
– Mole Crickets
– Navel Orangeworm
– Strawberry Root Weevil
– Tobacco Budworm
– Webworm
– Wireworm
– Wood Borer
– Artichoke Plume Moth
– Beet Armyworm
– Black Vine Weevil
– Bluegrass Weevil
– Cockroaches
– Corn Earworm
– Cotton Bollworm
– Cranberry Girdler
– Cucumber Beetle
– Fall Armyworm
– Flea Larvae
– Fly Larvae
– Fruit Flies
– Greater Peach Tree Borer
– Onion Maggots
– Plant Parasitic Nematodes
– Plum Curculio
– Raspberry Crown Borer
Root Aphids
– Sclarids
– Shore Flies
– Subterranean Termites
– Sweet Potato Weevil
– Thrips
– Ticks
– Tobacco Cutworm
– White Grubs
– Plum Curculio
– Beet Armyworm
– Black Cutworm
– Cabbage Maggot
– Codling Moth
– Corn Earworm
– Cucumber beetles
– Crane Flies
– Flea Beetles
– Fruit Flies
– Fungus Gnats
– Leaf Miners
– Humpbacked Flies
– Humpbacked Flies/Phorid Flies
Japanese Beetle
– Leafminers
– May/June Bugs
– Root Weevils
– Scarabs
– Sugarcane Stalk Borer
– Sweet Potato Weevil
Ants (Queen)
– Asparagus Beetle
– Banana Moth
– Banana Weevil
– Berry Root Weevil
– Billbug
– Black Vine Weevil
– Borers (Iris, Tree, Vine)
– Carrot Weevil
– Chafers (European, Masked)
– Citrus Root Weevil
– Colorado Potato Beetle
– Corn Rootworm
– Cranberry Root Weevil
– Cucumber Beetle (Spotted)
– Flea Beetles
– Gall Midges
– Grape Root Borer
– Grubs
– Ticks
How To Use Nematodes To Control Garden Pests! –

Where To Buy Beneficial Nematodes? 

Generally, you can find packages of beneficial nematodes mostly at your local garden store or plant nursery. 

In addition, you can also buy beneficial nematodes online on Amazon. 

  • Nematode Steinernema Carpocapsae (available on Amazon here)
  • Nematodes Steinernema Feltiae (available on Amazon here)

In Conclusion

If you are looking for a pest solution that is non-toxic to your garden, then nematodes are the perfect solution for you. Just make sure you use them properly and effectively.

Pick the best type of nematodes for your pest problem and know when and how frequently to use them. If you use them effectively, your pest problem will be long gone in no time.


Hello friends, I am Altiné. I am SO excited you are here! I am the guy behind Plants Heaven is a blog that shares information about preparing, creating, and maintaining gardens in and out of your home, regardless of where you live. My goal is to help you learn to love gardening and reap the benefits that come with it. I am still learning; therefore, the information I share on this site may not always be “expert” advice or information. But, I do my VERY best to make sure the information shared on this blog is both accurate and helpful.

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Gardening is one of the most relaxing and rewarding hobbies to have. When you take care of your garden properly and with care, it blooms beautifully. However, all gardeners must watch out for pests out there that may cause significant damages to your garden. If so, then nematodes might be the right solution for you. Then how to use nematodes to control garden pests?