Will Neem Oil Kill Beneficial Nematodes? Experts Explain

As gardeners, we all want to protect our plants from pests and diseases. And while commercial pesticides may seem like an easy solution, they often come with harmful side effects.

That’s why many of us turn to natural methods of pest control, such as neem oil and beneficial nematodes. But with so many options out there, it’s important to know how these treatments interact with each other.

In this article, we’ll take a closer look at neem oil and its impact on beneficial nematodes. Can you use them together? Or will neem oil kill off these helpful organisms? Let’s find out.

Will Neem Oil Kill Beneficial Nematodes?

Neem oil has become a popular choice for gardeners looking for a natural way to control pests. Its insecticidal properties make it effective against a wide range of garden pests, including aphids, mites, and whiteflies. But what about its impact on beneficial nematodes?

The good news is that neem oil will not harm beneficial nematodes. In fact, studies have shown that neem oil can be effective in controlling destructive nematodes while causing little to no harm to beneficial species.

Beneficial nematodes are microscopic organisms that live in the soil and help control pests by feeding on them. They are an important part of a healthy garden ecosystem and can help keep pest populations in check.

Neem oil works by disrupting the natural development of insects, preventing normal hormone releases that trigger growth and maturation. This property makes it effective against many garden pests, but it does not harm beneficial nematodes.

In fact, neem oil can even be used in conjunction with beneficial nematodes to control pests. If you have a problem with nematodes in your soil, you can drench the soil with a dilute solution of neem oil to kill nematode eggs. If nematodes are on the leaves, you can spray the leaves once a week.

It’s important to note that beneficial nematodes require soil temperatures above 55F to be effective. If you plan to use neem oil and beneficial nematodes together, make sure to wait until the soil warms sufficiently before applying the nematodes.

What Are Beneficial Nematodes?

Beneficial nematodes are microscopic segmented roundworms that occur naturally in soil around the world. They are an important part of a healthy garden ecosystem and can help keep pest populations in check.

There are more than 20,000 species of nematodes, but the ones used for pest control are entomopathogenic nematodes from the families Steinernematidae and Heterorhabditidae. These insect-parasitic nematodes enter the bodies of soil-dwelling pests through openings in the skin, such as the mouth or anus. Once inside, the nematodes release a bacteria that poisons the host pest and breaks down host tissue for the nematode to eat. The host insect dies within 48 hours.

A nematode’s life cycle includes six stages: egg, four juvenile stages, and adult. The third juvenile stage is when nematodes seek out new prey to infect. During this stage, they’re called infective juveniles. The nematodes reproduce inside a host’s body, and the young feed on it until they’ve consumed the whole thing. Then, hundreds of thousands of infective juveniles leave that host and move on to hunt down more insect pests, repeating the process over and over again until there are no pests left.

Beneficial nematodes require specific conditions to thrive. They need moist soil with plenty of organic matter and temperatures above 55F to be effective. They can be purchased from garden centers or online retailers and should be applied according to package instructions.

How Neem Oil Works As A Natural Pesticide

Neem oil is a natural pesticide that is extracted from the seeds of the Indian Neem Tree. It contains a chemical called Azadirachtin, as well as other active compounds, that make it effective against a wide range of garden pests.

As an insecticide, neem oil works in two main ways. Firstly, it serves as an anti-feedant when insects come in contact with or ingest it. This means that insects will avoid eating plants treated with neem oil, which can help to reduce pest populations.

Secondly, neem oil functions as a hormone disruptor and growth regulator to affected insects. This property disrupts the natural development of the insect by preventing normal hormone releases that trigger growth and maturation. As a result, insects that come into contact with neem oil are unable to develop properly and will eventually die.

Neem oil also has other functions. It serves as a fungicide and bactericide, which means it can help to control plant diseases caused by fungi and bacteria. Additionally, neem oil is effective against plant parasitic nematodes, which can be destructive to plants.

One of the benefits of neem oil is that it is compatible with beneficial nematodes. Unlike chemical pesticides that can harm microscopic organisms in the soil, neem oil will not harm beneficial nematodes. In fact, studies have shown that neem oil can be used in conjunction with beneficial nematodes to control pests without causing harm to the nematodes.

Research On The Effects Of Neem Oil On Beneficial Nematodes

Several studies have been conducted to determine the impact of neem oil on beneficial nematodes. One study examined the effect of neem oil on Steinernema feltiae nematodes. The researchers found that neem oil had no impact on the mortality or virulence of S. feltiae nematodes. However, they discovered that when adding soap to neem oil, the resulting spray killed off 13% to 25% of the beneficial nematodes. This suggests that care should be taken when combining soapy surfactants with neem oil to avoid unintentionally decreasing the nematode population.

Another study looked at neem oil’s effect on both bad nematodes (the parasitic Meloidogyne incognita) and good ones (the beneficial Heterorhabditis bacteriophora). They found that neem oil reduced destructive root galls by an incredible 88%. It also harmed the M. incognita nematodes, reducing their hatching rate by 85% and increasing their mortality rate by 68%. However, the study showed that neem oil did not harm beneficial H. bacteriophora nematodes at all.

Alternatives To Neem Oil For Pest Control In Gardens

While neem oil is a popular choice for pest control in gardens, there are alternatives that may be more effective and less smelly. One such alternative is Earth’s Ally Insect Control, which uses sustainably grown rosemary oil as its active ingredient. Rosemary oil has been recognized for centuries for its natural pest-repelling properties, and the high-quality rosemary oil used in Earth’s Ally Insect Control is grown in the U.S. from a single source of rosemary plants.

Earth’s Ally Insect Control also contains clove oil and peppermint oil, which work together with soap and an emulsifier to paralyze, suffocate, and repel soft-bodied insects like spider mites, aphids, and whiteflies. This product is effective against a wide range of pests and can be used on fruits, vegetables, flowers, and ornamental plants.

Another alternative to neem oil is horticultural oil, which works by suffocating small insect pests and mites. Horticultural oil sprays also have some fungicidal activity, making them effective against powdery mildew. However, they are not effective against all pests and may harm beneficial insects if used improperly.

When choosing an alternative to neem oil for pest control in gardens, it’s important to consider the specific pests you are dealing with and the potential impact on beneficial insects. Always follow product instructions carefully and use caution when applying any pesticide product.

Tips For Using Neem Oil And Beneficial Nematodes Together In Your Garden

If you plan to use neem oil and beneficial nematodes together in your garden, here are some tips to keep in mind:

1. Use a soapy surfactant: Neem oil works best when mixed with a soapy surfactant. However, it’s important to note that adding soap to neem oil can harm or kill some beneficial nematodes. If you do use a soapy surfactant, make sure to use it sparingly and carefully.

2. Wait for the right soil temperature: Beneficial nematodes require soil temperatures above 55F to be effective. If you plan to use neem oil and beneficial nematodes together, make sure to wait until the soil warms sufficiently before applying the nematodes.

3. Use the right amount of neem oil: When using neem oil, it’s important to follow the instructions carefully and use the right amount. Too much neem oil can harm beneficial nematodes, so make sure to use it sparingly.

4. Apply at the right time: To get the most out of your neem oil and beneficial nematodes, it’s important to apply them at the right time. Apply the nematodes first, then wait a few days before applying the neem oil. This will give the nematodes time to establish themselves in the soil before being exposed to the neem oil.

By following these tips, you can use neem oil and beneficial nematodes together to control pests in your garden without harming the beneficial nematodes that help keep your garden healthy.