How To Mix Neem Oil For Plants

If you're looking for an organic or natural pesticide, neem oil is a great option. Here's your simple guide on how to mix neem oil for plants.

Numerous research studies indicate that chemical pesticides have adverse effects on plants, humans, animals, and the environment.

As a result, more people are keen on using organic or natural pesticides.

Neem oil is a great option for a natural pesticide. It is versatile as it can be used as a fungicide or insecticide for vegetable plants and fruit trees.

In this article, we will discuss how to mix neem oil for plants and its application process

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How Does Neem Oil Work Against Pests?

Woman hands with sprayer, sprayed on flower leaves, take care of the garden

The neem oil has a component called azadirachtin. It has excellent defense capabilities against insects and bugs.

Azadirachtin’s effectiveness is twofold. First, it repels pests from the plants. Secondly, if consumed, it alters the hormonal structure of the pest interfering with feeding, mating, and molting.

Ultimately, this controls pest reproduction.

Neem oil is effective at preventing infestations of pests such as the spider mite, moths, scale, beetles, and fungi including black spot, powdery mildew, leaf spot, scab, blight, rust, and botrytis among others.

How To Mix Neem Oil For Plants Insecticide Spray

Women's hobby. Granny squirts and takes care of household plants and flowers

What You Need

  • 1L of warm water
  • 5ml Neem Oil
  • 1-2 ml mild soap silica
  • Garden sprayer or spray bottle
  • Gloves
  • Mask


1. Get Pure Neem Oil

The main reason you want to use pure neem oil as a pesticide is that you prefer organic farming and want to stay away from harmful chemicals, solvents, and preservatives found in most inorganic pesticides.

Although you may opt for ready-to-use neem oil insecticide spray, there is no guarantee these do not also contain harmful chemicals.

Making your own neem spray is the only way to be sure of its purity.

As such, it is best to source organic cold-pressed neem oil or neem oil extract. It is the purest form of Neem oil on the market.

2. Decide Between Using Mild Liquid Soap, Insecticidal Soap, Or Silica

As you already know, water and oil do not mix naturally.

Therefore, when making a neem oil pesticide spray, you require an emulsifier to break down the oil’s structure so that it can mix well with water.

Mild liquid dish soap, insecticidal soap, and silica are all effective at emulsifying neem oil.

Mild liquid soap is easily accessible and cheap as you could use regular dishwashing soap. Silica contains potassium silicate, which offers additional benefits to the plant. Potassium improves drought and stress resistance and strengthens cell walls.

3. Mix The Ingredients

Add the oil to the detergent in a spray bottle or garden sprayer. Close it and shake until the solution is well mixed.

Then add the warm water and shake to ensure it is thoroughly mixed. Your solution is now ready for application.

It is important to use warm water and not cold or hot water in your spray bottle. Warm water facilitates the dissolving process without breaking down the neem oil’s molecular structure.

How To Apply Neem Oil On Plants

Adult woman spraying plants in garden to protect from diseases
  1. Wear your protective gear including a mask, goggles, and gardening gloves before you start the application process.
  2. The best time to apply the neem oil is either early in the morning or the evening. Avoid applying the spray in the middle of the day under direct sunlight.
  3. Test out the neem oil spray on a few plants first before going on to spray the entire garden. Allow up to 24 hours before application to see if there are any adverse effects on the plant. In case the solution is too strong and causes sunburns, you will have an opportunity to dilute it further before using it on other plants.
  4. Use a sprayer to spread a generous amount of the neem oil mixture on the leaves. Take your time to apply both on the top and bottom surface of each plant leaf. Ensure that the leaves are fully covered with the oil including all nooks and crannies.

    Occasionally, shake the sprayer between applications to keep the solution well-mixed. It is okay if some of the neem oil solutions spills on the soil. It does not compromise the quality of the soil and it keeps away nematodes.
  5. Regularly spray neem oil on the leaves for preventative measures. Once a week is a good rule of thumb. If there is a mild pest infestation, spray the plants at least twice a week to kill off an invasive insect. Also, use 5ml more neem oil when making the spray.

Tips For Using Neem Oil As A Pesticide

Insecticide Spray Plants
  • It is best to use neem oil as a preventative pest control method rather than a curative method.
    While neem oil is effective at keeping away predatory insects and fungal diseases, it is not effective if there is a full-blown infestation of pests or fungi.
  • Ensure that the neem oil is fully emulsified and well mixed with water before spraying it on the plant.
    If it is not, a layer will form on top of the solution. Add small amounts of the emulsifier and warm water until the neem oil dissolves completely.
    Otherwise, it will spray out unevenly which inhibits its effectiveness. Also, the leaves that get coated in concentrated neem oil are likely to get sunburned.
  • Do not store already mixed neem oil. Even if the neem oil has emulsified, it will separate from the water over time. The neem oil spray is only viable for up to 8 hours.
    Make a fresh batch for every use. You may scale up the measurements if you are spraying a big portion of your plants or scale down for smaller jobs.
  • You may add other organic ingredients that promote the health of the plant to the neem oil spray, such as organic aloe vera powder or peppermint essential oil. 
    Peppermint ‘s fragrance helps to repel insects.
  • Do not use more than the recommended amount of neem oil. It will be too harsh on the leaves and cause sunburns.
  • Do not use your neem oil on new seedlings. They are fragile and prone to damage.
    The neem oil might be too strong for their developing leaves, stems, and roots.
  • Do not spray neem oil on the plants when it is raining or rain is about to start.
    The rainwater will wash it off before it has had a chance to be effective.

How To Mix Neem Oil For Plants: Is It Safe For Use?

Generally, neem oil is non-toxic to people, pets, and beneficial organisms such as earthworms and bees.

If concentrated neem oil gets into contact with your skin, it may cause irritation so when mixing it and applying it to the plants, you should wear gloves.

If ingested, concentrated neem oil may cause gastrointestinal irritation or inflammation, which may cause diarrhea or stomachache. Usually, these symptoms will ease with time. You may take painkillers or dehydration medicine to ease these symptoms.

Neem oil is best suited for use on root vegetables and other plants.

If you must use it on edible parts of a plant such as leafy greens, cucumbers, zucchini, etc., allow at least a week before harvesting to ensure all the applied neem oil has broken down.


Neem oil is an effective insecticide. It keeps away pests such as insects and fungi without leaving harmful ingredients on your plants.

You can use it throughout the lifetime of the plant for preventative measures and manage mild insect or fungi infestations.

We hope this article on how to mix neem oil for plants has been helpful. If you have your secrets on how to mix and use neem oils, feel free to comment down below.

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Jad Daou

Jad has always been passionate about growing plants. When he finished high school, he majored in biology, which makes him very knowledgeable about agriculture.