Should You Rinse Neem Oil Off Plants?

Neem oil is an all-natural insecticide and fungicide favored by many gardeners because of its proven effectiveness and safety. Spritzes of this potent insecticide and fungicide help keep plants healthy, happy, and looking their best. However, is it necessary to rinse neem oil off plants, especially if it is used regularly?

You do not need to rinse neem oil off plants because it will dry on the leaves and stems within a few hours. Its insecticidal properties will continue to be effective for about 5 days after application. The only time to rinse off neem oil is if you harvest edible crops sprayed within the week.

We will talk about why you should not rinse neem oil off your plants and how it works as an insecticide, fungicide, and leaf cleaner. I will then give some pointers on how you can maximize the benefits of neem oil before we dabble on additional benefits you can expect from using this in your garden. Let’s start!

Why You Don’t Have to Rinse Neem Oil off Your Plants

You don’t have to rinse neem oil off your plants because it does not harm or damage their leaves and stems. Neem oil is organic and completely biodegradable. It breaks down within just a few days of application but will remain effective for at least a week in keeping pests and fungi at bay.

In addition, you will realize why it’s unnecessary or even counterproductive to rinse neem oil off your plants once you understand how it works and how to apply it to your plants.

Let’s discuss it in more detail below:

Pest Control and Eradication Effect

Neem oil works by coating pests and insects with a light layer of oil, interfering with their ability to perform ordinary functions. They will find it progressively more challenging to do usual activities like walking, searching for food, hiding from predators, or even reproducing. This will eventually lead to death, usually within 2 days of application. 

Here are some pests that can be eliminated by neem oil:

Neem oil works best on soft-bodied pests. Results can be felt almost immediately upon contact. The insects start to move about slower than usual, and some may even be killed instantly.

However, for hard-shelled pests such as snails, Japanese beetles, or scale insects, you might need to resort to other methods to eliminate them quickly. 


Neem oil is a safe and effective natural insecticide. It can eliminate different types of pests and help keep your plants healthy and thriving.

However, you should know how to apply neem oil properly. The wrong application can lead to leaf burn, wilted stems, and an unhappy plant. 

Here are some pointers on how to properly apply neem oil to your plants:

Spray Only in Late Afternoons or Early Evenings

Neem oil can cause burns when it is exposed to harsh sunlight. That is why it is best to spray neem oil on your plants when the sun starts to go down.

Doing so will protect its leaves and stems from being scorched. This would also be great timing for nocturnal pests. Neem oil will be waiting for them when they emerge from their hiding spots to start looking for food. 

Spray at Least Once a Week

Neem oil doesn’t start to break down until after 5 days or so after application. This is why spraying this natural insecticide on your plants more than once a week would be unnecessary. It wouldn’t harm your plants since neem oil is entirely organic and safe, but you would just be needlessly wasting it.

If your plants are in the middle of an infestation, apply neem oil weekly, at least until the situation is under control. 

Azadirachtin, a natural chemical compound in neem oil, is responsible for attacking insects’ biological systems. It works as a pesticide and fungicide and starts breaking down around the second day after application. Weekly neem oil sprays will provide your plants with round-the-clock protection against pests. 

Reapply After Rainfall

Heavy rainfall will rinse neem oil off your plants. A light shower might leave some of it behind, but residual neem oil might not be as effective if your plant is currently infested with some type of pest.

It would be best to reapply neem oil after each rainfall. Give the plant some time to dry so that that neem oil won’t be washed off with any water dripping from the leaves. 

When watering your plants after neem oil application, make it a point to avoid the leaves and stems so as not to wash them away. Direct your watering hose or can toward the soil. Otherwise, you would need to reapply neem oil after watering. 

Other Uses Beyond Pest Control

Neem oil has other uses aside from being a safe and effective insecticide. It is a handy garden partner that you can turn to for help in keeping your plants healthy, beautiful, and happy. Having this in your garden at all times is a great way to simplify your plant chores. 

Here are some other ways neem oil benefits your plants:


Neem oil can also be counted on to kill fungal diseases in plants. It can be used as a preventive measure and a way to kill any existing fungi. For prevention, it is best to use neem oil every 14 days.

To kill fungi, spray neem oil all over your infected plants weekly until all signs of fungi clear up. Then, spray every 2 weeks to prevent a possible recurrence. 

Here are some fungal diseases that can be controlled with neem oil:

  • Black spot
  • Powdery mildew
  • Leaf spot
  • Scabs
  • Anthracnose

Cleans Leaves

Dust buildup on plants’ leaves is never a good thing. Dust can clog the leaves’ stomata – tiny pores responsible for photosynthesis, gas exchange, and hydration. Clogged stomata can lead to a multitude of problems for your plants.

Here are the main functions of the stomata:

  • Absorbing carbon dioxide needed for photosynthesis: If the plant is an air purifier, the stomata absorb harmful gases like formaldehyde from the environment. 
  • Aiding in transpiration by opening and closing, depending on the plant’s water needs. For instance, they close when it is hot and dry to help minimize water loss due to evaporation. 

Dust buildup can also make your plants’ leaves look lifeless and dull. If the leaves are textured, dust will settle in the grooves. If the leaves are variegated, dust will block sunlight absorption and affect your plant’s chromatic properties. 

You can use neem oil to clean your plants’ leaves. Use it regularly to avoid dust buildup and give your plants a layer of protection from pests and fungi.

Since neem oil is organic, it is safe to use every week, especially if your plants are infested with pests. Leaves will become shinier, smoother, and cleaner.

Here is how to clean your plants’ leaves using neem oil:

  1. Spray neem oil solution on a clean piece of cloth. Consider using microfiber cloths for cleaning leaves since these are soft and durable. Fabrics with rough surfaces may damage leaves. 
  2. Wipe the leaves gently until the neem oil is fully absorbed and the leaves are clean. Spray and wipe on the undersides as well. 

How to Make Neem Oil Spray

Neem oil is a safe and effective insecticide, fungicide, and leaf cleaner. It can be used for prevention and treatment if there is a current infestation.

If you’re a plant enthusiast like me, neem oil should be among the staples in your garden. It is safe, effective, and inexpensive. 

Here is how to make your own neem oil spray:

  1. Pour 1 gallon (3.8 liters) of water into a large jar.
  2. Add 1 tablespoon (14.79 ml) of liquid dish detergent or Castile liquid soap. The soap will act as an emulsifier. 
  3. Add 4 teaspoons (19.72 ml) of pure neem oil.
  4. Mix well.
  5. Pour into a spray bottle. 
  6. Store the remaining solution in the sealed jar and place it in a cool and dry location. 

Additional Benefits

If being a reliable insecticide, fungicide, and leaf cleaner is still not enough, neem oil offers even more benefits that will convince you to include this handy garden partner among your staples.

Here are some of them:

Safe for Pets and Other Animals

Neem oil does not leave any toxic residue that may harm pets or animals that may accidentally ingest plants that have been sprayed with this potent insecticide. It is completely organic, biodegradable, and non-poisonous. 

Neem oil is extracted from neem trees (Azadirachta indica), which are native to India and have no known adverse effects. 

Effective for All Stages of Insect Development

Neem oil kills insects in all phases, whether they’re adults, larvae, or merely eggs. It smothers eggs and larvae, effectively preventing them from transforming into the next stage. Neem oil alters the hormones of adult insects and stops them from feeding and functioning normally, eventually killing them. 


Neem oil may be a potent insect killer, but it does not harm earthworms. This is important because earthworms are among the most beneficial creatures in gardens.

These are some of the benefits of having earthworms in your garden:

  • Their excrement, known as worm castings, is rich in nutrients. Garden soil benefits significantly from the nitrogen, potassium, and phosphorus found in worm castings.  
  • They create pathways underground. These allow air and water to be absorbed by plants’ roots.
  • Their decaying bodies return nutrients to the soil. Decaying earthworms help fertilize it. 

Safe to Use Indoors

Neem oil is safe to use for indoor plants as well. It is not harmful to humans and pets. Neem oil is not toxic to the environment and will not make the air inside your home unsafe.

Neem oil has a light and distinct scent when sprayed on plants, but the smell quickly disappears. 

Keeps Mosquitoes at Bay

Neem oil keeps mosquitoes away. Mosquito infestation is always a problem in verdant gardens since leaves, bushes, and lush vegetation offer ideal hiding spots.

It is nice to know that neem oil provides benefits in this regard, too. It can keep your plants healthy while keeping you safe from mosquitoes while enjoying your garden. 

Doesn’t Pollute Air and Water

Neem oil is non-toxic and biodegradable. It doesn’t contain harmful elements that may pollute the air when spraying it on your plants. It won’t pollute groundwater and nearby bodies of water, either, because it does not contain harmful chemicals. 

Safe to Use on Fruits and Vegetables

Since neem oil is organic, it can be used on fruits and vegetables. You can spray it at every stage of the planting season, up until the day of harvest. All you have to do after harvest is rinse the neem oil off with some warm water and soap.

Neem oil is not meant for human consumption, so it is best to rinse all fruits and vegetables before consuming them. 

Here is how to rinse neem oil off your produce:

  1. Fill a jar with 1 quart (0.95 liters) of clean water.
  2. Add 1 tablespoon (14.79 ml) of liquid dish soap.
  3. Add 1 tablespoon (14.79 ml) of vegetable oil. This acts as an emulsifier to loosen the neem oil.
  4. Mix well. 
  5. Pour into a spray bottle.  
  6. Spray all over your fruits and vegetables.
  7. Allow the soap mixture to stay on your produce for 2-3 minutes.
  8. Rinse it off with water. Use a pressurized hose or place the produce under running water to wash away the neem oil and soap mixture effectively. 

Key Takeaways

Neem oil is a safe and effective insecticide and fungicide. It is entirely organic and non-toxic, so you do not have to rinse it off your plants. It won’t damage leaves and stems even if it is applied regularly. 

The only thing to remember is not to use neem oil during the daytime when your plants may still be exposed to sunlight because it could cause leaf burn. Otherwise, you can spray neem oil weekly to prevent and treat pests and fungi. 

Dr. Moritz Picot

Dr. Moritz Picot is a horticulture enthusiast and the founder of, where he serves as the lead content writer. He established the website in 2022 as a valuable resource for both gardening aficionados and beginners, compiling all the gardening tips he has accumulated over the past 25 years. Alex has a passion for nurturing plants, transforming backyards into inviting spaces, and sharing his knowledge with the world.

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