Neem oil not working is an issue that would be frustrating to the end-user because of the issues you want to tackle. The primary reasons for the oil not working are if it is expired, you are using the wrong application method, or you didn’t supplement it with other means. Instead, apply freshly bought oil and give it time to work.Neem Oil Not Working

Read on, and you will learn the right reasons and ways to fix them.

Why Is Neem Oil Not Working On The Plants?

Neem oil is not working on plants because it is old and expired, or you may have applied it in the wrong method. It can also be because you aren’t waiting for it to work; you have applied the oil once, used it on the wrong bugs, and over-diluted it.

– Old or Expired Neem Oil

Your neem oil not working can be due to many reasons, but you must keen and check when did you purchase the oil, and have you checked the expiry date? When products expire, their effectiveness reduces, which could happen to your oil, and the oil can be weaker when used.

Every product has an expiration date after which it becomes ineffective, and so does neem oil. After expiration, this oil loses its healthy properties, making it inefficient for aphids and other insects. It is safer to use the oil one year after purchase; however, when the expiration has passed, when you use it, it wouldn’t be working as well as you wish.

If the oil in your shelves is old but not expired, try if it kills the insects. If not, the reason could be poor storage, like exposing the product to direct sunlight. Poor storage could also cause recently bought oil not to work, and you will be left wondering if neem oil works. Once you buy neem oil, store it in a cool space away from the direct sun.

– Wrong Application Method

It could fail to work if you use the wrong neem oil application technique on your plants. Gardeners should spray the top and bottom of the leaves and other parts where aphids and other insects’ attack. Failure to spray the most crucial parts of your tree with the oil will not kill the insects, and this way you won’t be tackling them in the right way.

If it is your first-time applying neem oil on trees, and you need to know the best way to apply it, it could fail to work. Most farmers will start smearing the oil on tree bark and leaves to prevent insects from feeding on the plants. On the other hand, the best oil application methods are foliar sprays and soil drenches, but when you don’t go ahead to do this, it will

Whether you want to kill insects in your outdoor or indoor plants, choose the best application method. You must also apply on top and underside of the leaves to remove any insects hiding in those spaces. If you are applying on a small garden, use a spray bottle for application.Why Is Neem Oil Not Working

– You Are Impatient

You may go ahead and wonder how long ago it was that you apply neem oil on your trees. The latter is because most gardeners are impatient. After all, they want to see instant results, and this is why you should know that neem oil works after four to five days, so give it time if you can still see insects crawling on the tree after the first day of application.

One of the frequently asked questions is how long neem oil takes to kill houseplant pests. Many farmers want results almost immediately after applying a pest control method, which doesn’t work with neem oil. This is why waiting for a couple of days is ideal for the oil to work, and before these days are over, you could blame the oil for not working.

– You Applied the Oil Once

If you have waited up to a week and the oil hasn’t worked, it could be because you applied it once. This oil is less strong than chemical insecticides, so it takes many applications to see an impact.

When the oil is applied to the plant, it first coats the leaf. The bugs will then ingest it as they feed on the leaf, and once it gets in the insect’s body, it starts destroying the cellular level. If you applied once, some plant parts won’t be coated with the oil, and the insects will feed on those, keeping them alive for longer, and they continue reproducing.

– You Are Using on the Wrong Bugs

Another reason your oil didn’t work is if you are spraying the wrong bugs. Neem oil works on insect pests like spider mites, fruit flies, and not birds, mammals, and bees. You must get a toxic compound for these organisms to eradicate them from the garden.Using Neem Oil on Bugs

Neem oil insecticide doesn’t work on all bugs and insects. For example, you cannot use oil on honeybees, earthworms, or birds. Neem oil spray won’t also work on mammals as well if you are using it to tackle them. You must find the best insecticides for the bugs in your plants to kill them.

You may also wonder, does neem oil kill assassin bugs? The oil doesn’t kill assassin bugs unless you spray it directly on their skin to suffocate them with a heavy dose of them.

These beneficial insects are neem oil safe, which is advantageous because they play essential roles in the farm’s ecosystem. And if you are wondering what insects does neem oil repel, aphids are a good example.

– You Diluted the Oil Too Much

Neem oil cans, tins, and sachets have instructions on diluting the oil before applying. Also, if you don’t know and wish to learn how to mix neem oil and castile soap, contact a professional for guidance.

Diluting neem oil in too much water or mixing it wrongly with a soapy emulsifier could make it ineffective. This reduces the oil’s concentration and won’t kill the insects as fast as it should.

What Are The Solutions To Make Neem Work?

The solutions to make neem oil work are to use fresh oil and to be more patient. Additionally, you should also be patient after you have used it, reapply it to the insecticide, ensure that you dilute it properly, and lastly, be aware of how it doesn’t kill all insects.

– Use Fresh Oil

Does neem oil kill leaf-footed bugs? The oil kills leaf-footed bugs in their nymph stage but works best when fresh. Which is why when you would be applying expired oil to these bugs and aphids will not work.

When the oil expires, it loses its healthy proteins, which are toxic to the insects. Therefore, it won’t have an effect after application. Hence, you must go ahead and use fresh oil, it is better, you can try to get the seeds and extract the oil afterward, and use it right.

To ensure you offer the best plant care, always check the expiration date of the neem oil on the container. And if you buy fresh oil, store it in a cool place away from direct sunlight. Exposure to sunlight causes oxidation in the oil, reducing its effectiveness, if you have one and wouldn’t want it to go bad in the long run.

– Be Patient

Neem oil failing to kill insects in your garden can be frustrating. If you are experiencing such, check if your oil is expired. You should also wait about a week before concluding that the oil did not work.

Neem oil doesn’t work on insects instantly. The insects take four to five days to die, but you can give it a week. If it’s past a week and the insects have not disappeared, you can start worrying about why it didn’t work.

Also, note that this oil will only work if it is correctly applied to the plants. You should use a sprayer pump or a foliar spray to reach all the parts of the plant. When spraying, ensure you reach the upper and undersides of the leaves and on the bark to kill all the insects.Solutions To Neem Oil Not Working

– Reapply the Insecticide

Spraying neem oil once or twice doesn’t kill insects because its impact is not immediate. You can use the oil with insecticidal soap to increase its effectiveness.

To be more specific, for effective results, ensure you reapply the oil twice or thrice to cover all the parts of the plant. You must now try to reapply the oil also provides enough on the leaves for the insects to ingest and die.Neem Oil Not Working Details

– Dilute the Oil Properly

Before applying and reapplying neem oil to your plants, dilute it in the right proportions with water and a soapy emulsifier. You can check the correct oil bottle or sachet ratios or call a professional.

Once everything mixes well, spray the oil on the trees immediately. Keeping the mixture for a day or two reduces its effectiveness, and this way, as you add a few drops of oil, it will help to make the solution uniform.

– The Oil Doesn’t Kill the Type of Insects

Have you checked the type of insects you are dealing with? Although neem oil kills aphids, Japanese beetles, and spider mites, it won’t work on some insects like bees, butterflies, and earthworms.

If your garden is infested with pests and insects’ neem oil doesn’t work on, consider other pest control methods. You can use potent pesticides to kill unwanted insects or spray them with insecticidal soap.


You can fix the problem by using freshly bought oil, diluting it in proportions, and spraying it on insects it can kill. To summarize this article;

  • Neem oil is a perfect pest control method, but it could only succeed if expired, misapplied, and used on the wrong pests.
  • Neem oil could fail to work if it is expired or was stored wrongly, is overdiluted, or has been applied only once. Also, this oil takes four to five days to work and must be applied using the correct methods.
  • Applying the oil once or overdiluting it makes it ineffective for pests, so you must mix it in the proper proportions.
  • You should wait until a week to see the oil results before concluding if it worked effectively.
  • Always check the expiration date and apply it correctly on the trees. If you try all the solutions and the bugs don’t disappear, consider another pest control method.

If your neem oil fails to work, first find out the reason to get a better solution.

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