Neem oil for hornworms is an excellent remedy and works very well when used in the right way and at the right time. This is why many farmers and gardeners deploy the use of neem oil spray, which can also be made at home, for their tomato plants.Neem Oil for Hornworms

In this article, we will take you through the best and the most effective way of making and using neem oil spray against the hornworms found on tomatoes or other plants so let us get started.

How To Use Neem Oil for Hornworms?

To use neem oil for hornworms is by first inspecting the plant, arranging the neem oil spray, spraying the plant, and finally applying aftercare and preventative measures so that the hornworms do not find their way back to destroy the plants.

Neem oil is a natural oil that has the power of a pesticide and insecticide, all packed into one powerful oil and extracted from the neem seeds and tree. The use of neem oil goes back to medieval times when people used to crush the leaves of neem to extract the oil and then use it in their daily lives.

Neem oil is thus a very effective and easily available remedy and the best thing about it is that it is non-toxic to humans, making it safe to use. So it is of utmost importance that when the hornworm is seen on any of the plants, they are taken care of because otherwise they will spread and cause havoc on the plants.

1. Inspect the Plant

The first step in the process is to inspect the plant for the presence of hornworms or their eggs. The hornworms look like caterpillars and are very fuzzy to the touch. Horworms are a considerable concern for tomato plant owners because their presence can ruin their crops entirely and also have adverse effects on the soil for future crops, which is why inspecting it thoroughly is a necessary step that you should be taking.Inspecting Hornworms in Plant

They belong to the family of Sphingidae and are also referred to as hawk moths in the gardening community. These hornworms have around 1450 species, and each of them can attack plants of tomato, potato, or pepper, more than once in their life cycle, hence, you must know and be aware of the crops that you are spraying, and inspect where they have infested the most.

Try to start inspecting the plant from the top and make your way to the roots of the plant. The color of these hornworms is quite like the color of the leaves so spotting them can be a struggle sometimes. When these worms sense danger, they might try and hide under a leaf or a flower, so make sure you thoroughly check the plant and its parts.

Before going into a much deeper cleanse of the insect, if the invasion is small or has just started, you might want to hose the insects with plain water a medium pressure. The water will remove the insects and you can manually remove them from around your plants.

Remember that this will only work when the insects are tiny in number. If the number of insects is much larger, follow the further steps to get rid of them, keeping your plants healthy and thriving.

2. Pick the Right Time

The worst time to spray the neem oil for hornworms is at night because for the neem oil to work well, there should be daylight and a suitable warm temperature that will help the oil in removing the insects and the disease, if there is any.

At the same time, you must be keen that you pick the right time, which should be during the very early morning or after the sun is not directly on the plant any longer.Hornworms Right Time to Kill

The other worst time to use neem oil spray as a preventative measure against hornworms is when the plant is growing up. At this time, the plants can stop growing because of the harsh neem oil which is why it is always better to apply the oil on a mature and well-grown plant that can sustain itself in the best way possible.

Choose a dry and sunny day for spraying the plants as this will help the neem oil work better. Start by spraying the plants from the top then make your way down to the roots of the plant.

It is totally fine if the neem oil spray goes here and there because it is safe for almost all plants except for the ones with wispy leaves like oregano, basil, and thyme. After carefully and generously spraying the plants with neem oil, leave the plants be for some time.

Also, make sure that the neem oil is not sprayed more than once in a 12-hour window, which is why you should use neem oil in the appropriate way and amount for maximum positive results. The natural antimicrobial chemical compound found in neem oil is called azadirachtin and is very potent against very wide and diverse varieties of insects and bugs that may harm your plants or pets, so be sure to avoid this issue.

The hornworms are a big problem to the plants because they can destroy them very easily and also reproduce in a good number so if left untouched, their invasion can get out of hand. The plants that are most affected by the hornworms include tomato plants, potato plants, and all sorts of pepper plants, and these plants can be generally planted together in a vegetable garden, and pick the time when they aren’t under the brightest blaze of sun.

3. Arrange the Neem Oil

The second step in the process is arranging the neem oil spray that will be sprayed on the plants to remove the insects and their infection. The neem oil has a slippery nature and insecticidal properties, which is why when it is sprayed on the insects, they lose their grip on the plant and fall away and, secondly, are affected by the insecticidal properties of the neem oil.

So whatever neem oil solution you arrange, make sure that it has that slippery nature and also a bitter smell that is the evidence of the presence of neem oil. Hence, make sure that the oil is free from any clouds in the middle, or having a very bitter smell.

You can buy a neem oil spray from any plant shop or online because they are available everywhere and with various chemicals added that offer additional powers to the spray. In case, you want to spray the neem oil plants with edible fruits or vegetables on them, it is best to use the neem oil that has the least amount of chemicals and preservatives in it.

This will ensure that your plants are not getting sprayed on by any chemicals that would lead to being toxic later on. If you are using such a spray, make sure to wash your sprayed-on fruits or vegetables very nicely before consuming them.

Additionally, you can also choose to make your own neem oil spray at home. You can do this by getting a gallon of water with two to three tablespoons of neem oil and a kitchen-safe dishwashing liquid in a container. You can also mix them with a bit of liquid dish soap, and the mixture would be uniform.

Mix all of these ingredients together until a solution is formed. You can use this homemade solution like you would use the store-bought one, but this solution might not have a long shelf-life as the other one because it is devoid of any and all preservatives.

4. Spray the Plant

The next and most important step in the process is to spray the plant with the solution of neem oil, either homemade or store-bought. The first thing that you will need to remember here is that protective gear is of utmost importance.Spraying Neem on Plant

It will save you from getting any bugs or insects on your clothes and later on to your skin. Wear eye goggles, gardening gloves, overalls, a face mask if sprays are involved, and gardening boots if you plan on going inside the garden with taller plants.

For spraying, the container should have a nozzle with adjustable hole sizes because this will make the spraying much easier and non-tiring. You can also use the spray more widely and consistently throughout the plant.

First, you can do a small patch test and see the result, and how much is it safe to be sprayed thoroughly, and wait 24 hours for the best outcome, then you may check and see if you need to dilute it more and work accordingly.

Too much neem oil on hornworms can be bad for the plants and the soil under them. This is because the neem oil can alter the chemistry of the plants and the soil if used in a larger amount than usual so it is best to keep the usage of neem oil in check. One way of keeping the use of neem oil in check is by making a calendar or a timetable for the spray of the oil.

This will help in keeping track of the progress and will also let you know when you last used the neem oil. Another way is to spray the neem oil on all the required plants at once so you wouldn’t need to go back and forth in spraying them, and thus no accidentally spraying the plants that do not need the spray coat.

5. Apply Aftercare

The last step in the process is to apply the aftercare which will include making a schedule of reapplication of neem oil and also fixing protective and preventative guards that will help safeguard the plants from future invasions and infestations. Ensure that after use, you store the neem oil in a cool and dry place, so it does not go wrong.Hornworms Infestation Aftercare

Lastly, the neem oil will start killing the insects and when it does, make sure you remove the dead insects from the plants as they will rot there, as well as the organic debris left along the plants that you are spraying on. Sometimes, the rotting insects can have a very bad smell and attract other beings.

However, remember that these worms will not go away after only one coat of neem oil spray and this is because the hornworms may have laid eggs that can take much more time to be destroyed by the neem oil than the actual hornworms. In short, it is important that you would spray it again after a few days and examine the result.

You will need to apply at least two to three coats of neem oil spray on the hornworms to make them go away completely. Make sure that after every spray, if there are any dead hornworms on the plants, remove them from the plants. Otherwise, the hornworms will start to decay on the plants causing another problem for the plants and yourself.


In this article, we talked about the simplest way of using neem oil for hornworms but in case you missed anything, here is a short conclusion of the important points in the article:

  • The best way to use neem oil for hornworms is by first inspecting the plant, arranging the neem oil spray, spraying the plant, and finally applying aftercare and preventative measures.
  • If the invasion is small, you can use a medium-pressured water hose to spray the hornworms.
  • The hornworms affect the tomato, potato, and pepper plants and can spread very easily from one plant to another.
  • Make sure to remove the killed insects from the plants as they can cause a very bad smell and attract other beings to the plants.
  • After using the neem oil, make sure it is stored safely.

Here we come to the end of the article: how to use neem oil for hornworms. Following is a simple few-stepped process of using neem oil against hornworms but make sure that you use the oil according to the given directions.

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