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Benefits of Neem Oil for Tomatoes

The Benefits of Neem Oil for Tomatoes and Other Plants

You may have heard that neem oil is a great natural insecticide and may be wondering if there are other benefits of neem oil for tomatoes and other plants. Yes, there are and we are going to discuss some of them in this article. So keep reading to find out!

Benefits of neem oil for tomatoes

Before we go into the benefits of neem oil, let’s look at what neem oil is exactly.

Related: How Much Peroxide for Plants Should You Use?

What is Neem Oil?

Neem oil is extracted from the seeds, bark, and other parts of the Azadirachta Indica tree.

This tree originated in India, and Southern Asia, but now it’s possible to grow and nurture a Neem tree in your backyard.

Its leaves and barks have been in use for thousands of years in Southern Asia.

They used it to detoxify their blood, enhance immune system, and support respiratory system.

The seeds contain a high concentration of Azadirachtin, a naturally occurring insecticide. But extracts from other parts of the tree have been used in manufacturing cosmetics, toothpaste, and soaps.

What are the Benefits of Neem Oil for Vegetables and Other Plants?

According to EPA, neem oil plays the following roles once it gets into the plant’s system.

  • Repellant
  • Antimicrobial
  • Nematicide
  • Growth Inhibitor
  • Anti-feedant
  • Insecticide
  • Attractant

Below is how it works, in detail.

Neem Oil is an Effective Insecticide

Neem oil works as a systemic insecticide where it’s absorbed into the plant’s system and transferred to the insects once they suck or chew into it.

Once the insect consumes it, neem oil causes a reaction that stops its growth, kills it, or prevents it from feeding on the plant further.

Neem oil also kills insects in all growth stages, regardless of whether it’s outdoors, indoors, or in greenhouses. It may take up to 3 days before you see the result, but you can rest assured the effects will be long-term.

Some of the insects that neem oil eliminates include:

  • Mites
  • Caterpillars
  • Mealybugs
  • Leafhoppers
  • Aphids
  • Thrills
  • Whiteflies

Based on the list, neem oil is effective on pests that chew or suck. It often doesn’t harm beneficial insects like ladybugs and bees.

However, don’t take any chances. Once you see these beneficial insects around, you can delay for some time or spray only on the affected areas.

It’s an Effective Fungicide and Bactericide

Neem oil has also proven effective in eliminating the following fungi:

  • Black spot
  • Leaf spot
  • Root rot
  • Powdery mildew
  • Rust
  • Tip Blight
  • Anthracnose
  • Fire Blight

(You may also want to read this article on sulfur vs copper fungicide).

It’s Great for Indoor Tomato Plants

Whether you want to grow your tomatoes during winter or love growing plants indoors, neem oil is suitable for that.

Neem oil is also ideal for plants growing in greenhouses. As I’ve already mentioned, neem oil kills several types of pests; it will kill aphids, Whiteflies, or any other insects that may attack your plants indoors.

I also mentioned that it’s safe to use around pets.

Neem Cakes can be Used as Fertilizer

Not only does neem oil act as a pesticide, but neem Kernels/cakes can also be used to make organic fertilizer with a considerable amount of the NPK (Nitrogen, Phosphorous, and Potassium).

One of the problems gardeners experience is excessive Nitrogen in the soil. When used with other fertilizers, especially Urea, Neem oil solves this problem by reducing the release of Nitrogen.

Neem is great as a fertilizer since, even though it slowly releases nutrients into the soil, it doesn’t leach harmful metals such as lead, a problem you’ll find in some chemical fertilizers.

It also provides food for earthworms and other soil-based organisms. These organisms facilitate soil aeration, and they contribute to the soil’s organic matter when they excrete as well as when they die.

The pesticide nature of neem oil is also an added advantage since this fertilizer will also kill the soil-based pathogens.

Neem Oil is Effective against Nematodes

Nematodes can be quite a nuisance since they will feed on the roots of vegetables, killing the plant eventually.

Eliminating them can be quite challenging since once the nematodes have penetrated the roots, most chemical pesticides stop being effective.

Neem oil can help deal with that since it contains two naturally occurring nematicides – notriterpenoids and isoprenoids. The decomposition process of neem oil releases fatty acids such as amino acids, ketones, aldehydes, etc. which kill nematodes.

How Do You Use Neem Oil on Vegetables?

Neem oil is pretty easy to apply. Below are the things you’ll need:

How to apply:

  1. Most manufacturers have their ratios, so ensure you check the instructions. Some may require 2 to 4 tablespoons of Neem oil in one gallon of water.
  2. You can add up to 2 tablespoons of dishwashing soap if you’re dealing with plants with hairy leaves, such as tomatoes. Excess soap may damage the plants. To avoid this, you can test with different quantities on a few plants.
  3. Mix well and use a garden sprayer to spray all sides of the plant. Keep shaking as you spray to make sure you have a balanced mixture at all times.
  4. Wait for 7 to 14 days before applying again.
  5. Use the mixture within 8 hours of mixing and do not store any leftovers.
  6. Use gloves and other protective gear to protect yourself from irritations. It has no poisonous fumes, but you can wear respiratory masks if you find the smell unpleasant.
  7. If the leaves look dull after you applied Neem oil, chances are you used the wrong soap or too much soap. Wash off the soap with a lot of water and monitor the plants for some time before applying again.

When is the Best Time to Apply Neem Oil?

To prevent spraying butterflies, and ladybugs, it’s best to apply neem oil early in the morning or late in the evening.

Also do not spray when it’s too hot (above 90 F) since this may cause the leaves of the plants to curl, or suffer sunburns. And it would help if you didn’t spray it when it’s too cold.

Too much neem oil can also burn the foliage, especially for new transplants. You should also avoid using Neem oil if your plants are showing any signs of stress.

You can also use it on a few plants or a section of the plant. And monitor the results before spraying all the plants.

Is Neem Oil Safe?

Neem oil is safe to use up to the harvesting season. So yes, you can eat the tomatoes after spraying with neem oil. But be sure to wash the tomatoes thoroughly before consumption.

You may also want to know the answer to this question, can you eat vegetables sprayed with neem oil?

Neem oil is sometimes sprayed to make the fruits and leaves look glossy and shiny. So instead of spraying right before harvesting, you can harvest them and spray after. But if you’re treating diseases and repelling pests, it’s best applied way before harvesting.

According to EPA and Plantvillage, Neem oil has no adverse effects on the environment. However, it may be toxic to people if consumed directly. So you should be cautious and keep it away from kids. Some people may also be allergic to Neem oil.


Neem oil has a lot of benefits to tomatoes and other plants. It’s an excellent insecticide, fungicide, and bactericide. Neem extracts can also be used in manufacturing organic fertilizer. It’s also environmentally friendly.

Since it comes in different concentrations, make sure you follow the instructions and always use soap when spraying on tomatoes. However, neem oil shouldn’t be consumed directly, and you should thoroughly wash vegetables and other edible plants sprayed with neem oil before consumption.

Neem oil benefits for tomato plants

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Thursday 28th of July 2022

If I used a Neem oil soak around my tomato plants roots, how long do I have to wait before I can harvest the ripe tomatoes?


Friday 29th of July 2022

Hi Fran,

Since you used the Neem oil around the roots and not on the tomato fruits directly, 1 week should be enough. And be sure to wash the tomatoes very well before consumption.

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