What is Neem Oil and How to Use It to Rid and Prevent Plant Pests

Key Takeaways

  • Neem oil is an organic insecticide for indoor and outdoor plants as it contains compounds that repel and disrupt the feeding and breeding patterns of many insect pests.
  • Neem oil is safe to use in organic gardens instead of chemical insecticides as it is made from seeds of the neem tree.
  • Neem oil is effective against a wide range of insect pests, including aphids, mealybugs, spider mites, whiteflies, and thrips.
  • Preparing neem oil insecticide is very easy, as it needs only a few drops of oil, liquid soap, and 1 liter of water.
  • Neem oil can be applied to plants in a variety of ways, including as a spray, a soil drench, or a foliar application.
  • Neem oil is also relatively safe for beneficial insects and other non-target organisms, making it a popular choice for organic and sustainable pest management.
*FYI, we prefer to use this particular brand of neem oil because it's premixed and in spray form - most importantly, it just works. Click here to skip down for more information.

Neem oil is an organic and very popular insecticide used in gardens to keep pests and diseases at bay.

It has been used for centuries to control mites, aphids, fungi, and other common garden pests.

Neem oil is a great choice for organic gardeners because it is safe to use with good bugs like ladybugs and bees and doesn’t hurt them.

Professional gardeners directly spray neem oil extract in their gardens to eliminate pests and diseases.

In this post, you will learn how to use and apply neem oil to your plants and what to do if your plants are thoroughly infected.

For more information on houseplants, go back to our Houseplants main page.

What Is Neem Oil?

What Is Neem OilPin

Neem oil is a natural and useful vegetable oil that is produced from Azadirachta indica, the neem trees that are native to the Indian subcontinent and Africa.

Neem oil is made from crushed neem seeds mixed with a solvent, such as water or alcohol. However, there are other methods of producing this oil.

This oil is extracted from the seeds of these trees and contains azadirachtin, which is the main and active ingredient in neem oil.

While preparing the most commercially available neem oil, the azadirachtin compound is first extracted from the seeds or other parts of the neem plant.

In some cases, an entire plant or some parts of the plant are used. The preparation methods determine the actual strength of the active ingredients in neem oil.

Then the compound is combined with organic substances or soaps to make it an all-purpose or stand-alone insect spray.

Gardeners can use neem oil on houseplants or outdoor garden plants instead of synthetic fungicides, insecticides, or pesticides.

This beneficial oil is also considered a cure for every ailment in the Indian subcontinent.

Neem oil can also be used for medicinal and skincare purposes. Many people still buy neem oil to treat any kind of skin disease.

How Does Neem Oil Kill Insects?

Neem oil contains a number of active compounds that work together to kill insects and keep them from infesting plants.

The primary active ingredient in neem oil is azadirachtin, which disrupts the hormonal system of insects and prevents them from feeding, developing, and reproducing.

Neem oil disrupts the hormonal activities of the pests and inhibits their growth. Without this chemical compound, there are around 70 different organic complexes present in the oil that interfere with reproductive cycles and feeding mechanisms.

Neem oil contains other compounds that repel insects and prevent them from laying eggs on plants, in addition to azadirachtin.

These compounds, which have antifeedant and growth-regulating properties, include nimbin, nimbidin, and salannin.

In addition, neem oil kills insects by clogging their breathing pores, causing them to suffocate and die. Overall, neem oil is a broad-spectrum insecticide that works against a wide variety of pests.

How Do You Apply Neem Oil On Plants?

How Does Neem Oil WorkPin

Neem oil is usually applied as a foliar spray and is very important for indoor or outdoor gardeners and even hydroponic growers.

The spray is directly applied to the plants to get rid of bacterial or fungal diseases. It is extremely effective against aphids, mealybugs, and spider mites.

When to Use Neem Oil on Plants

When To Use Neem Oil On PlantsPin

Neem oil is super effective throughout the entire growing season. So, you can apply it whenever you notice a pest infestation.

Don’t worry about the stage of the pests’ life cycle because the oil will destroy everything.

While applying neem oil to the plants, you should try it either in the early morning or late afternoon. Applying this substance during the midday sun can be harmful because the combination of direct sunlight and this oil can burn the leaves.

This is why we suggest that gardeners apply neem oil in the late afternoon. In this period, the temperature is low, and the oil can stay in contact with the plants for a longer period of time.

Remember that neem oil doesn’t kill all the pests in your garden overnight. So you need to keep applying the oil for a few consecutive days. Even if you notice some activity from pests, continue applying the oil.

Is Neem Oil Toxic?

Neem oil is generally considered to be non-toxic to humans and animals, including pets when used as directed. According to the National Pesticide Information Center [1], neem oil has low toxicity to mammals, birds, and bees, and is not known to cause adverse health effects. 

Even the Environmental Protection Agency (EPA) strongly recommends using organic neem oil for driving away harmful insects and neem cakes as soil amendments.

With that said, neem oil can be irritating to the skin and eyes, so it is important to wear protective clothing and avoid getting it in your eyes or mouth.

How to Use Neem Oil on Plants

Neem oil products are available in various formulas, such as wettable powder, dust, cake, granules, and neem oil concentrate.

You can buy these forms in a bottle and dilute them before applying. Remember that neem oil is effective when applied for 3 to 4 consecutive days.

You can repeat the application if it is necessary.

You need to follow these steps to prepare the solution and apply it:

Preparing the neem oil solution

Preparing The Neem Oil SolutionPin

Firstly, you need to purchase cold-pressed Neem oil, a spray bottle, and insecticidal or liquid soap.

Once these materials are bought, get a gallon of water and mix the oil with the water and a small amount (a teaspoon) of the soap. This soap will act as an emulsifier in the solution.

Now, add one or up to two tablespoons of organic and pure Neem oil to that solution.

This solution will be strong enough to protect your plants from garden pests.

Applying the solution

Once the solution is prepared, it is time to use it on plants. It is best to apply this oil mix to all the plants, including old and young ones.

Before treating the plants with neem oil, you need to test their sensitivity. To do this, you need to apply the solution to a small area of a leaf.

Now wait for 24 hours. If there is no sign of damage, then you can apply the mix to kill pests.

To keep the plants healthy and destroy all pests, you need to spray the neem oil mixture carefully on both sides of the leaves because eggs and larvae often rest on the underside of the foliage.

Common Ways To Apply Neem Oil In Your GardenPin

There are three common ways to apply neem in the garden:

Dormant Spray Application

Dormant spray application means applying the oil during the dormancy period. It is best to apply the oil via direct application when the plant is in dormant condition (during the winter).

During this period, it will be easier for you to kill the overwintering pests and eggs. Remember that you should wait until the temperature reaches a minimum of 40 degrees Fahrenheit.

Foliar Spray

Using Neem Oil on Indoor PlantsPin

Foliar spraying involves applying the neem oil directly to the plant’s leaves during the growing season. Make sure you dilute the spray before applying it to the plant.

Soil Drenching

The soil-drenching method is another way to use neem oil. In this process, the oil is first diluted and then poured into the soil.

The roots absorb the solution, and the cells distribute it throughout the whole plant, including the leaves.

As a result, the sap-sucking insects will start avoiding the plants. This method is effective for treating soil-borne bacterial or fungal diseases.

It isn’t so easy to use neem oil on your plants. Although there are three common ways to apply neem oil to plants, foliar spraying is the most common method of application.

Simply mix the oil with water according to the product instructions, then thoroughly spray your plants with the solution until all surfaces are coated.

Alternatively, if your plant has already contracted a pest or fungus, you can drench it in neem oil or mix it into the soil around its root system.

Reapply the solution

Don’t stop using neem oil insecticide until all the pests are killed. Remember that if a single pest remains alive, it will reproduce and spread the infestation again.

Experts always recommend spraying the oil mixture on the plants at least once a week.

Common Issues to Avoid While Applying Neem Oil to Plants

There are three common mistakes that many people make when applying oil.

Common Mistakes To AvoidPin

Not Diluting Neem Oil Mix

Not diluting the neem oil mixture can have several pitfalls.

  • Firstly, neem oil is a potent natural pesticide that can harm plants if used in high concentrations. Applying undiluted neem oil to plants can lead to leaf burn, stunted growth, and even death in severe cases.
  • Secondly, undiluted neem oil can be harmful to beneficial insects such as bees and ladybugs, which are essential for pollination and pest control.
  • Finally, undiluted neem oil can leave a residue on fruits and vegetables that can be harmful to humans if consumed in large quantities.

Don’t Apply Neem Oil In the Middle of the Day

There are some disadvantages to applying neem oil in the middle of the day.

  • Firstly, neem oil can be phototoxic, meaning that it can cause damage to plants if applied during periods of high sunlight. This can lead to leaf burns and other forms of damage.
  • Secondly, applying neem oil during the middle of the day can increase the risk of evaporation, which can reduce the effectiveness of the oil.
  • Finally, applying neem oil in the middle of the day can also increase the risk of harming beneficial insects such as bees and ladybugs, which are essential for pollination and pest control.

Wear Protective Gloves When Handling Neem Oil

If you touch neem oil without wearing gloves, it is unlikely to cause any serious harm or toxicity. However, neem oil can be a skin irritant for some people, causing redness, itching, and irritation. In some cases, prolonged or repeated exposure to neem oil can cause dermatitis or an allergic reaction.

To avoid skin irritation or allergic reactions, it is always recommended to wear gloves and protective clothing when handling neem oil, especially if you have sensitive skin or a history of allergies.

Benefits of Using Neem Oil for Plants

Benefits Of Using Neem OilPin
  • Neem oil is safer to use as it is not toxic for pets or wildlife. Chemical insecticide sprays often contain harmful substances that have toxic effects on animals.
  • Organic neem oil degrades quickly under sunlight and during rainfall. On the other hand, synthetic products don’t degrade easily, and hence, they exert a long-term adverse effect on the environment.
  • Like other chemical insecticides, neem oil doesn’t create a chemical death zone around the plants. It eliminates chewing and leaf-sucking insects. Therefore, beneficial insects remain unharmed.
  • Neem oil destroys every stage of an insect’s life cycle, which can be egg, larva, or adult. Azadirachtin may work as an antifeedant and hormone disruptor. It destroys the larvae before they turn into adults [2].
  • Synthetic pesticides cause harm even to beneficial soil dwellers, like earthworms. But neem oil encourages their activities.
  • This organic oil can efficiently handle the spread of common garden pests such as mites, scales, aphids, leafhoppers, caterpillars, whiteflies, mealybugs, mites, and thrips.
  • Neem oil also prevents some common fungal infections, including powdery mildew, black spot, rust, scab, tip blight, anthracnose, leaf spot, etc.
  • Neem oil comes in different concentrations and formulas. It can be available in five major forms, such as wettable powder, dust, granules, liquid spray, or emulsifiable concentrates.
  • The most amazing benefit of using neem oil is that pests never become resistant to it. In many cases, pests become resistant to synthetic products by altering their genetic code. Once they become resistant, more toxic and strong chemicals are recommended for killing the insects.

Disadvantages of Using Neem Oil

Disadvantages Of Using Neem OilPin

Although neem oil has many benefits, it can create problems if used improperly. If you aren’t careful while using it, you can do harm to your plants as well as to beneficial insects.

Without this, concentrated neem oil can cause skin irritation if it comes into contact. Therefore, you should wear protective gear while applying.

Make sure your eyes and lungs are protected when you use the powder form. This powder may cause moderate-to-mild irritation to your lungs if inhaled.

Keep your children away from the area during the application.

Moreover, this substance is slightly harmful to amphibians and fish. This is why experts often recommend not using neem oil on aquatic plants.

Using Neem Oil on VegetablesPin

What Neem Oil We Use

We don’t like to make our own solution, so we use this particular neem oil. It’s already premixed and ready to spray. We like the simplicity of it and have had a lot of success with it. 


Is Neem oil organic?

Neem oil is a completely natural and organic insecticide that comes from the neem tree. The Environmental Protection Agency (EPA) calls it a biopesticide, which just means it’s made from natural stuff like animals, plants, and minerals. But not all neem oil products are certified organic, so make sure to check the label or ask the manufacturer. It’s a super safe and effective way to get rid of pests without using harsh chemicals, which is why organic gardeners love it.

Is Neem oil safe or toxic?

Neem oil is safe and non-toxic for humans, animals, and the environment when used properly. It has been used for centuries in Ayurvedic medicine and is a popular ingredient in organic gardening practices. However, it is important to follow proper precautions when using neem oil, such as wearing protective clothing and avoiding contact with the skin, eyes, and mucous membranes. Some people may experience allergic or respiratory reactions to neem oil, so it is essential to test a small area before applying it to the entire plant. Overall, neem oil is a safe and effective alternative to synthetic insecticides.

How long does it take neem oil to dry?

Neem oil takes around an hour to completely dry when applied to a plant. It is recommended to apply neem oil in the early morning or late evening to allow sufficient drying time before the sun is at its strongest. Applying neem oil during the hottest part of the day can cause the oil to evaporate quickly, reducing its effectiveness.

Is DIY Neem oil spray possible?

Yes, making your own neem oil spray for plants is possible. First, mix 2 teaspoons of neem oil and 1 teaspoon of liquid soap with 1 quart of lukewarm water. Shake it up until all the ingredients are combined. Pour the solution into a spray bottle and spray it on all the plant surfaces, including the undersides of leaves and stems.


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