How to Use Neem Oil on Plants for Maximum Effectiveness

If you are a gardener, you know how important it is to take care of your plants and keep them healthy and beautiful. If not, I hope this article will help you understand the importance of using neem oil insecticide on your indoor plants for maximum effectiveness.

You may think that if you are an indoor gardener, your plants will be immune to pest infestations. Unfortunately, pests can be carried into your home from the outdoors and attack the plants you have inside.

For centuries, neem oil has been used in India as an organic pesticide and insecticide against many different pests, including spider mites, aphids, beetles, caterpillars, and white flies. It is also one of the most cost-effective pesticides available!

This article is a comprehensive guide regarding the use of Neem oil insecticide on indoor plants. By the end, you should have a clear understanding of neem and its uses, as well as its effectiveness.

What is neem oil, and What does it do for plants?

For those who don’t know, neem oil is a byproduct of the Indian Neem tree. It contains many different compounds, including azadirachtin, limonoids, and fatty acids. This is what gives it its insecticidal properties as well as making it highly effective for plant growth!

Neem oil works as an antifungal property, which can help with common diseases such as powdery mildew, black spot, and rust on your plants.

It can also help with many other issues like leaf curl in tomatoes or low fertility in plants growing indoors!

What kind of bugs does neem oil kill?

Neem oil kills bugs like:

  • fungus gnats
  • Japanese beetles
  • adelgids
  • wooly adelgids
  • sawflies
  • aphids
  • sawfly larvae
  • cabbage loopers
  • lace bugs
  • scale
  • cabbage worm
  • chinch bugs
  • mealybugs
  • spider mites
  • crickets
  • earwigs
  • flea beetles
  • mole crickets
  • squash bugs
  • pear slugs
  • tent caterpillars
  • grasshoppers
  • pear psyllas
  • thrips
  • green stink bugs
  • white flies
  • psyllids
  • gypsy moth caterpillars
  • rose slugs
  • harlequin bugs
  • rust mites 
  • leaf hoppers
  • and other soft-bodied insects.

And what about all the rest?

Neem oil does not harm humans or animals, is non-toxic to pets and wildlife. It also doesn’t kill beneficial insects, lady beetles, ladybug, birds, bees, butterflies, or earthworms.

I know what you’re thinking: if you are an organic gardening enthusiast, you don’t want to use harsh chemicals on your plants! That’s not a problem because neem oil is entirely safe insect control for your indoor and outdoor plants, as well as humans. It also doesn’t have an offensive smell like other pesticides, which can cause problems if they are sprayed inside homes or offices.

Neem oil is a 100% natural pesticide that works differently from conventional chemical and synthetic pesticides because it targets specific insects or plant pests, killing them directly. Neem acts more like an organic fertilizer that helps make the plant healthier in general. The plants’ resistance against various pest species is increased.

Many organic fertilizers on the market can help improve plant health and growth. Still, most of them won’t actually protect your plants from insects. Neem oil is different because it contains almost all of these benefits in one product!

Wait, there’s more

  • making your soil more fertile for increased root development
  • stimulating new leaf growth (which means more photosynthesis!)
  • increasing essential oils production (great for aromatherapy)
  • making flowers healthier, which will lead to bigger harvests! 
  • It’s also believed to increase germination rates when used on seeds before planting them too.

You’ll see better results with less work after applying neem oil to your indoor garden. It works incredibly well to protect your plants from harmful insects, including spider mites.

You should also know that the Environmental Protection Agency (EPA) has registered neem oil as a pesticide. It is now used by many different commercial or industrial growers.

How Does Neem Oil Help Plants?

Neem oil works as an insecticide by disrupting insects’ growth hormones, which affects their development and reproduction cycle. So, neem oil kills insects or stops them from being born. Beneficial bugs will do just fine.

While the exact mechanism of how neem works are unknown, it may be because neem tricks insects into thinking they’re not on a plant when they walk across it, so they don’t feed on them.

However, this doesn’t happen instantly because houseplant pests need time to ingest the oil. Otherwise, they won’t even feel its effects (similar to how humans can eat large amounts of vegetables without getting sick!)

So if you want your plant pest problems gone immediately, ensure your neem oil solution is highly concentrated with pure neem oil. 

How do you dilute neem oil?

There are several different methods to dilute neem oil with water.

  1. The first way is by using a neem oil concentrate solution and mixing it with filtered or distilled water in the proper concentration (30% neem, 70% clean water). This is probably the easiest method since you don’t have to worry about measuring out specific amounts of each liquid. Just make sure that when you mix them together, they form a uniform color. Otherwise, parts might be too diluted or undiluted!
  2. Another option is by heating up either one part pure organic neem oil or three parts previously boiled filtered/distilled water until both liquids combine into a smooth neem oil mixture without separating colors at all. You can then use this new solution over the top of a second neem oil mixture of previously boiled filtered/distilled water and pure organic neem oil to reach the proper concentrations.
  3. Last but not least, you can use a spray bottle with a nozzle attachment to mix together your own solution. You can do that by slowly adding one part of neem oil into five clean filtered or distilled water parts. While shaking it up in between each addition until they’re combined evenly. This will be good for larger applications since you’ll have plenty leftover!

How do you use neem oil on plants?

spray neem oil

Neem oil insecticide is usually sold as a liquid concentrate that needs to be diluted with water before use. You can also buy it as an organic pesticide that already has the proper concentrations. You just need to mix it with water for application. We recommend doing this since you’ll save money in the long run!

Ensure your neem oil solution is about 30% neem oil and 70% clean, potable (preferably distilled), or previously boiled filtered water. This will ensure that no dangerous chemicals are used on plants. Similar to how people shouldn’t drink unfiltered tap water because of all the different kinds of bacteria present due to human contamination.

So, how do you apply neem oil to indoor plants?

Neem oil is a contact pesticide which means you spray neem oil directly onto the surface of your plants. The good news is that it has low toxicity levels, so it will be fine if sprayed in high concentrations or on sensitive areas. Still, we recommend keeping an eye out for any signs of leaf damage just to be safe!

You can use a spray bottle and simply spray the bottom and top surfaces of leaves and stems. Try not to get too much of it directly on the soil because it might make them damp and allow diseases like root rot to grow more easily.

Sometimes, if a plant has an infestation of some kind on its exterior leaves, spraying neem oil insecticide directly onto those areas is not necessarily going to help. That’s because there are likely tiny eggs or larvae hidden under the soil. That’s the reason it’s crucial to take care of pests that may be lurking in the roots system before they become a problem!

Ensure you rinse all tools used with soap and water immediately after application since neem is very sticky once applied!

How often can you use neem oil spray on houseplants?

The recommended frequency of spraying neem oil on indoor plants is once every week for the first month, then twice a month after that as the oil will last for a long time.

If you see any signs of pest activity on your plants after this period, then use neem oil spray again to kill insects and wipe out their eggs before they have a chance to spread. You can do this as much as necessary since it’s entirely safe for humans, pets, and all types of indoor houseplants!

Only spray during late evening or early morning hours when temperatures are lower. Because if applied at other times, this will increase the chances of burning leaves due to high levels of ultraviolet light exposure.

Apply more often in areas where you have noticed problems with insects and pests before. Especially if your plant has been recently transplanted into new soil, which can cause them to be very weak!

Is it safe to use neem oil on houseplants?

There really aren’t any side effects when it comes to the safety of using neem on indoor plants unless you overdo it (which isn’t hard).

The only time someone would experience discomfort from the oil is by ingesting large amounts of leaves treated with neem oil directly (it causes diarrhea and vomiting). 

Still, since we always recommend spraying diluted solutions onto plant surfaces, this shouldn’t be a problem.

What plants can you not use neem oil on?

It can be sprayed on herbs and veggies right up until the day before harvest, making it ideal for both ornamental plants and edible crops.

Neem oil can burn the foliage of any sort of plant, regardless of the type. It may also harm plants by burning them. Do not use it on new transplants or those that are under stress.

It must be applied to the plant’s leaves completely for the pesticide to be effective. Still, it is good to conduct a small-scale test before using it to the entire plant. If you detect no signs of toxicity in that area, you can treat the whole plant.

Can you use too much neem oil on plants?

Neem oil is safe for all indoor plants, but if you overdo it, the leaves will have a bitter taste to them, which can deter pests from eating any further.

Ensure your garden plants are not exposed to direct sunlight for several hours after application, or they will burn!

What should I do if I see signs my houseplant was harmed by neem oil?  

If you notice any signs that your plant might’ve burned, it’s best not to continue using it since these side effects don’t disappear quickly!

It might take weeks before your plants recover, depending on how much you used, but if the damage is extensive, then there’s no guarantee it will ever look the same. 

If this happens to you, just use neem oil in much lower concentrations and directly spray it on affected areas.

Which Neem oil is best for plants?

There are many different types of neem oil for plants, but the most common one used is organic cold-pressed Neem Oil which works best.

It’s essential to make sure that you read the ingredients on your bottle. It should only contain 100% pure organic oils and no other additives or preservatives, as this can be harmful to your plant! 

As long as you buy neem oil products with all-natural ingredients, there shouldn’t be anything stopping you from using them effectively!  

Can neem oil help human bodies?

Yes, Neem oil is effective in many ways when it comes to your health.

Neem Oil can be used as a natural treatment for lice. If you apply the Neem oil on the scalp twice or thrice a day, then this will help to kill lice and their eggs within two hours. Also, using neem in cosmetics is helpful for skincare.

Using neem oil during pregnancy is also safe. It has antifungal and antimicrobial properties that are beneficial to the body. Also, you can apply this on your hair or beard to get rid of dandruff caused by a fungus infection.

Another new application of neem is in toothpaste. Neem has been used for centuries to prevent decay and gum disease.

Neem oil is also helpful in controlling allergies, arthritis, asthma, etc., by strengthening the body’s immune system. There are various neem capsules available that can be taken daily to manage these problems without any side effects. As they do not have any chemicals or preservatives.

Neem oil is also effective in killing bedbugs which often infests homes and blood-sucking pests that cause fever, malaria, etc. So if you are looking for an all-natural product to kill these pests, then neem oil can be the best solution available at your home. This is without causing any harmful effects on our health or environment.

Why is neem banned in Canada?

Neem oil is banned in Canada because it doesn’t have any of the required approval labels on its bottle. This means that it hasn’t been tested for safety or effectiveness before being sold to customers.

Even though neem has many benefits, there are still some risks involved, but they’re minimal when using organic products!

If you want safe treatment options, then try out a more natural pesticide such as horticultural oils. These ones haven’t been associated with harmful health effects, unlike neem oil so far.  


So that wraps up our comprehensive guide regarding using neem oil insecticides on plants. 

Be sure to let us know if you’ve tried organic neem oil spray as pesticide solutions onto your home or office greenery. We’d love to hear about how well it worked! 

Happy planting everyone 🙂

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Passionate about urban gardening, indoor growing solutions, and sustainability. Believes in growing our own food and eat fresh and better food by getting back to basics, growing a fruit and vegetable garden, and cooking from scratch.

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