Using Neem Oil on Tomato Plants

Tomatoes are delicious, so it’s no wonder people enjoy growing them in their homes. However, if you’re looking to grow them successfully, you must prepare for destructive pests that can wreak havoc on your plant species. Growing a variety of tomato plants is an exciting hobby since you can taste them all. It helps to take corrective measures to prevent aphids and bugs from ruining your hard work.


Not everyone prefers using insecticides, which is why natural remedies are preferred since they are less harmful to the environment and soil. Neem oil contains an active ingredient called azadirachtin that keeps pests and bugs away from your tomato plant. However, there are some key tips you need to keep in mind to ensure you are utilizing it properly. For example, you can spray neem oil directly on plants and use it as a soil drench, allowing it to kill and repel bugs instantly. It works exceedingly well against larvae and nymphs but also produces desirable results against garden pests.

The active chemical in neem oil effectively kills or repels more than 200 types of insects and pests. Neem oil achieves this result by altering the plant’s taste, preventing the pests from reproducing. However, it can take several days before it kills the bugs off, making it worth diluting it and applying generously to your tomato plants. It is a much safer substitute than insecticides because it doesn’t negatively affect your tomato plant, making it safe for consumption.

Let’s explore the intricacies of neem oil use on tomato plants.

The Complete Guide for Neem Oil Use on Tomato Plants

Using neem oil on tomato plants requires a comprehensive approach since there are many things to keep in mind when using it effectively. You may be dealing with a variety of bugs and pests targeting your plant species. You should utilize your neem oil solution in the most efficient ways to deal with this problem. Let’s explore the steps or stages of using neem oil to kill and repel your garden bugs.

Buy Neem Oil Concentrate from a Garden Shop or Online Store

Many people choose to purchase pre-mixed neem oil sprays. However, it helps to create your own since it becomes more effective that way. You can also use it to ward off spider mites, which are more difficult to deal with than other bugs and insects. By creating a custom neem oil solution, you can also save some money.

The first step involves buying a bottle of neem oil concentrate from a garden shop or online store. Then, you need to mix soap and water to create the ideal sprayable solution. Although many brands sell neem oil, you can choose Bliss or Verdana as your go-to choice.

Choose Organic Liquid Soap Instead of One With Chemical Additives

Oil is an immiscible liquid, which means it doesn’t mix at all with water. To facilitate the mixing process of neem oil with water, you need to add organic liquid soap. Unless you do this, your spray solution will be pretty ineffective against the pests targeting your tomato plants. You’ll achieve similar results by using any kind of liquid soap to serve the function of an emulsifier. Still, it is best you choose one with a minimum number of chemicals.

You will also notice better results if you choose soaps with essential oils since they increase the solution’s effectiveness against aphids and various pesky pests. Some liquid soap brands you can try include Dr. Bronner’s, Mrs. Meyer’s, and Safer Brand. They will produce desirable results and act as efficient emulsifiers.

Buy the Right Sized Garden Sprayer (0.5, 1, 2-Gallon)

To use neem oil on your tomato plant, you need a functional garden sprayer in various sizes. You can choose to buy handheld sprayers in half, one, and two-gallon sprayer bottles. However, an important tip to keep in mind is that neem oil quickly becomes ineffective after it is diluted with water. For this reason, you need to apply your solution to your tomato plants within an hour of creating the mixture. So, you should avoid making large quantities of the solution at once since you will waste your expensive neem oil.

Unless your garden is particularly large and you’re spraying various plant species at one time, you don’t need to use your two-gallon handheld garden sprayer. A one-gallon sprayer is typically enough for most gardens. Once you see pests and insects near your tomato plants, you should have your products ready and waste no time spraying your vegetable plant. You can use a magnifying glass to figure out which insect species is infesting your plant, allowing you to use your neem oil effectively.

Label the Pests and Insects on your Tomato Plant

When your tomato plants begin to grow, you should make it a point to observe them closely. Observing the tomato plants helps you identify the pests threatening them. To become more efficient at this process, you can join several bug-related social media groups to become more proficient at identifying different bug species. You can also take a picture of your plant leaves and put it up online, allowing others to help you identify the garden pests.

However, you can also use certain apps like iNaturalist and Bug Identifier, which are not always accurate but can provide some clarity. Once you detect and identify the bugs appearing on your tomato plants, you can use your neem oil solution to kill them and prevent them from spreading further.

Dispose of the Decaying Leaves and Prune Your Plant Properly

Depending on how much your pest infestation has advanced, your tomato leaves will exhibit signs of curling and drying. If they fall near the roots, they will provide shelter to the pests and prevent the neem oil from working its magic. Pests like spider mites can easily find ways to survive by hiding under the leaves and maintaining their distance from the neem oil. This is why it’s in your best interests to cut the foliage off yourself when you notice they are curling up and drying.

Tomato plants can survive damage to their leaves and branches, especially if the growing season is still in full swing. Cutting off several branches and leaves will not inhibit your plant’s growth, meaning it is okay to do so. Many people don’t know that it is important to cut off the withered leaves since the plant will keep producing nutrients for the dead foliage. Additionally, dead foliage also prevents the neem oil from covering your plant properly, decreasing its effectiveness. When cutting off dead foliage, you should remember not to damage the central stem since that will affect your tomato’s ability to grow taller.

Use the Appropriate Amount of Solution to Coat Your Tomato Plants

Before you treat your tomato plants with neem oil solution, you must know how much of it you’ll need. Depending on the number of tomato plants in your garden, you’ll need to use different-sized sprayers. If you have one to four tomato plants, you will need a sprayer capacity of half a gallon. When treating five to nine plants, you will use a full gallon of solution for effective treatment. If you’ve got a big garden with more than ten tomato plants, you need to utilize your two-gallon sprayer for maximum effectiveness.

When spraying your plants, it’s good to be thorough and coat every square centimeter of the surface. It’s not a cause for concern if you cover your plants with too much neem oil since they will dry off within two hours.

Mix the Perfect Ratios to Create the Ideal Concentration

As we’ve discussed, our main ingredients are neem oil concentrate, water, and liquid soap. These will be added to a handheld sprayer to mix the perfect ratio of ingredients to target your tomato plants, allowing you to make enough mixture to target your entire garden species. As a rule of thumb, you need to mix one tablespoon of neem oil and two teaspoons of liquid soap into half a gallon of water. For one-gallon and two-gallon mixtures, simply double the ingredients accordingly. This gives you two and four tablespoons of neem oil for one and two-gallon sprayers and one and two tablespoons of liquid soap, respectively.

If you’ve just noticed a pest infestation near the tomato plants, you can spray them once a week to prevent the spread. However, the pest infestation might progress quickly, making it reasonable to apply the neem oil solution every four days for four weeks.

Spray Your Plants Within an Hour of Dilution

As we’ve mentioned, the neem oil mixture will start to lose its potency if you let it sit for more than an hour. So, you should use neem oil straight away and spray your tomato plants for maximum effectiveness. If you’ve forgotten about the mixture and let it stand for 12 hours, you don’t need to throw it away. You can apply a soil drench, which will be beneficial for your tomato plants. It’s important to use organic liquid soap for this reason because chemicals can be harmful to your tomato plant when used as a soil drench.

Spray Your Plants Around Early Evening to Avoid Burning Them

You should avoid spraying your tomato plants when the sun is rising since the oil particles will heat up and cause them to burn. Warm and hot days can cause your plants to die if you apply neem oil at the wrong time. Once the sun is beginning to set, you can apply a large amount of neem oil to your tomato plants to ensure they are dripping slightly. However, don’t go overboard and completely drench your plant since that is counterproductive. As long as every bit of the foliage is efficiently covered with your mixture, you will kill or repel the destructive bugs within a few days.

Choose the Best Day for Spraying Your Tomato Plants

It is best to avoid spraying your tomato plants on windy days. This prevents the neem oil from blowing on your face. Although it is mostly risk-free to humans if it makes contact with the skin, you should avoid accidentally ingesting it since that will send you to the hospital. If you cannot avoid spraying it on a windy day, make sure you spray it downwind to prevent any liquid from touching your skin. If you make contact with the mixture, just clean it off thoroughly using soap.

Utilize Various Angles for Spraying Your Tomato Plants

Spraying your tomato plant vigorously with neem oil will prevent the bugs from hiding under the leaves. You should target the leaves’ underside to cover all portions of the foliage and ensure the bugs cannot avoid the neem oil.

If you have a tiny bit of solution left in your handheld sprayer, you shouldn’t throw it away since that’s a waste of money. Instead, you should drench the soil with it and pour some water over it to effectively target the infected tomato plants. Pay attention to how your plant responds to this treatment. If it responds well to the diluted soil drench, simply add what’s left from the sprayer directly into the soil. This is effective because the tomato plants will siphon the azadirachtin and circulate it within the plant. As aphids or spider mites bite into the plant, they will ingest some of the active ingredients and experience its damaging effects.

Clean Your Garden Sprayer Properly After Each Use

Cleaning your garden sprayer after each use is important because it prevents it from getting clogged. This step is also useful if you use the same garden sprayer for different mixtures, allowing you to avoid spraying your tomato plants with other solutions, such as copper fungicide. However, there are no real side effects of reusing your garden sprayer several times as long as you’re using the same neem oil mixture.

Store Your Neem Oil in a Dry, Cool, and Dark Place

Neem oil concentrate is expensive, so you need to store it in a dark, cool, and dry place. This will prolong its expiration date and prevent the neem oil from going bad before its time. If you store it in a hot and humid place, it might lose its potency quickly. If you have a pantry, you can leave your neem oil there since dark and cool places are preferred. However, you should keep it away from other sensitive products to prevent cross-contamination.

Harvest Your Tomatoes a Few Days After Applying the Neem Oil

As your tomatoes begin to near their harvest time, you should wait at least five to seven days before eating them. You need to give enough time for the neem oil to dry completely to ensure your vegetables are safe for consumption. However, if you’re still a bit hesitant about eating your tomatoes because you sprayed them a few days ago, rinse them in soapy water to remove all traces of stubborn neem oil deposits.

Dealing With Extreme Infestations – Use Soapy Water Sprays

If you’ve decided not to use harmful insecticides and are not seeing quick results with the neem oil application methods, you can spray your plants with soapy water. If you’re using your neem oil solution on your tomato plants once every four to seven days, you can create a soap and water mixture and spray it onto the tomato plant between the main treatment. So, you will be spraying your tomato plant every day with different mixtures for up to one month.

For example, if you’re spraying your tomato plants with neem oil on day one, you should spray it with soapy water on days two to five before using neem oil again on day six. Continue this trend for two to four weeks for an aggressive treatment to kill off all spider mites, which can bounce back from many attempts. When creating the ideal soapy water mixture, it is best to mix four tablespoons of liquid soap with one gallon of water. Remember that using the organic variety prevents your tomato plant from siphoning any harmful chemicals.

Final Verdict

Using neem oil properly on your tomato plants will protect them from pest infestations. You should always prioritize prevention as the best strategy since it will keep your plants healthy and allow them to grow quickly. Neem oil is an excellent insecticide substitute and should always be preferred since it produces similar results. If you’re worried about spider mites and aphids, you should follow the instructions laid out in this article to repel or kill them before they can siphon off too many nutrients from your tomato plants. The fifteen steps for effective neem oil use will help you break down the process into actionable steps to keep garden pests at bay and help your tomato plants to thrive.