Nematodes are little worms that live in the soil of your garden and yard. You may be wondering if these nematodes are in fact friends or foes to your gardening efforts. The truth is that it depends on the type of nematode that's residing in your soil. Many of the nematodes that exist in nature are beneficial to you, because they take care of some of the pests you wouldn't want in your garden, such as the Japanese Beetle grub. Of course, there are some nematodes that can be detrimental to your garden and eat your plants, but this is a much smaller group of species. It’s hard to tell whether or not your soil has either kind of nematode in it because they're so small, but that doesn’t mean you can’t reap the benefits of the helpful varieties.

Beneficial Nematodes

long nematode on a rubus fruticosus plant

Beneficial nematodes are one of the best predators of soil-based problem insects around, and they're a safe way to eradicate those pests. These nematodes prey upon over 200 different types of insects in the ground without harming the other beneficial organisms you enjoy having in your yard. That means that your earthworms, ladybugs, and bees will be totally safe while the problem insects' grubs and larva are feasted upon. That’s a better outcome than you'd get by using pesticides to eliminate these pests from your soil, which wouldn't discriminate between insects.

How do Nematodes Work as Pest Control?

Nematodes can sense their prey from the carbon dioxide emissions, waste products, and heat they emit. Once a nematode finds a grub or larvae that they want to eat, it will enter it through one of its bodily openings. Once inside, the nematode secretes a bacteria that essentially turns the prey into food for the nematode to consume. It takes about 24 to 48 hours before the insect being eaten dies, after which the nematode is able to continue eating and living inside of the host. The bacteria that’s produced by the nematode isn't harmful to humans or their pets, which makes nematodes one of the best forms of soil-borne pest control to have in your gardening arsenal. Once all of the pests in the soil have been eliminated, the nematodes themselves will eventually die off, because they'll no longer have a food source. When that happens, they decompose and enrich the soil.

What Makes Nematodes Special?

japanese beetle grubs, pests that nematodes eat

You may be wondering what makes beneficial nematodes so special when it comes to pest control, and the answer to that lies in their many benefits. They’re able to target a wide variety of insects as hosts, because they don’t require any specific nutrients to survive. They can kill an insect within 48 hours of entering it. They can be added to your garden easily and are viable for weeks when stored correctly. They can survive for a time without finding a host. To top it all off, insects cannot become immune to the bacteria released by nematodes like they can with pesticides. Beneficial nematodes really are the friends you need in your soil.

Getting Nematodes in Your Garden

The good news is that if you’re facing a lot of grubs and larvae in your soil, you don’t have to do anything complicated to try to attract nematodes to your garden. You can actually purchase beneficial species of nematodes and release them into the soil. Several companies even sell beneficial predators like these online. There are a few species of nematodes to choose from, so check with the dealer you use to see what pests that particular species prefers. Typically, you’ll be buying a million or so nematodes at a time depending on the size of the area that needs to be treated. Most companies will give you guidelines about how many you should purchase to ensure adequate application.

Nematode Storage and Application

You’ll want to follow the instructions on the package when it comes to storing and applying your nematodes, as the steps may differ between brands. The following instructions are typical of what you might read on those packages.

You can often store your nematodes in the refrigerator for up to a month before applying them to the soil. To apply them, you'll usually have to mix them with water and spray them in the problem areas. You’ll want to wait until the temperature of your soil is between 55 and 85 degrees, and make sure to spray them at a time when the sun is not beating down on the ground. Applying your nematodes later in the day or on a cloudy day is sure to improve their survival rate. You don’t want to keep in them the freezer, try to store them after you’ve added water, or leave them in a hot car or container for too long before application. Each of these things can prove deadly for your nematode friends.

Most of the nematodes that you’ll encounter in your soil will be beneficial, as they eat many of the pests that cause gardeners real headaches during the growing season. Alternatively, you can easily work your own nematodes into the ground to take advantage of all of the pest control benefits they provide. Imagine how nice it’ll be to have a lawn that’s not eaten up by grubs or a garden free of pests — and all thanks to your friend, the nematode.