How Often Can You Use Neem Oil On Plants?

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By now, you’ve no doubt heard of the miracle product known as neem oil. This all-natural tree extract shows up in beauty products, healthcare, and a wide range of agricultural applications.

Yet you’re probably a bit confused by the mixed messages out there on how useful neem oil is for plants.

holes in plant leaves - would neem kill the pestsPin

Neem oil comes from the pressed fruit of the neem tree, which is native to India and Africa. 

Derived from the neem tree, neem oil has been used for centuries to control pests, as well as in medicinal and beauty products.


Neem affects insects differently than chemical solutions. While it can take up to two weeks to see results, it’s far more successful at eliminating infestations in the long term.

Neem oil is labeled for use on soft-bodied pests such as aphids, beetle larvae, caterpillars, leafhoppers, bees, butterflies, Japanese beetles, mealybugs, thrips, spider mites, and whiteflies.

Another controversy is whether neem is safe for agricultural use.

While lauded in most of the world, neem oil is currently banned in Canada due to the potential side effects of misuse. 

The active ingredients in neem oil begin to decompose after being mixed with water. This makes the mixture most effective within 24 hours. 

Some neem oil products also control fungal diseases such as powdery mildew, leaf spot, and black spot. It combats fungi by preventing new spores from germinating.

Knowing how often to use neem oil on plants protects them from potential damage. It will also help protect beneficial insects from coming into contact with this natural insecticide.

Related: Check out this article on What Bugs Neem Oil Kills.

In this article, we’ll dive deep into all the details of how often to apply neem oil to plants.

How Often Can You Use Neem Oil On Plants?

Regarding natural pest control for plants, neem oil for plants is a go-to solution for many gardeners.



It’s a natural insecticide that can help control various pests, including aphids, spider mites, whiteflies, and mealybugs.

However, how often can you spray neem oil depends on various factors, such as the severity of the infestation and the type of plants in question.

As a general rule, neem oil is just for eliminating infestations.

Yet, you can use it as a preventative every 2 to 3 weeks. However, like any pesticide, it can have harmful effects if used incorrectly.

But how often you should use neem oil on plants ultimately will depend on each individual plant’s needs.

Another consideration when using neem oil for plants as a pest control solution is how long does neem oil last on plants?

Neem oil does not have a long residual effect, so it is recommended to reapply it every two weeks or after rainfall. Applying neem oil at the proper time is essential for effective pest control.

How long does neem oil take to work? This is another common question that arises.

While the time takes neem oil to work depends on the type and severity of the infestation, neem oil can take up to 48 hours to start working.

Be patient and make sure to follow the instructions carefully.

How Often To Use Neem Foliar Sprays

Neem foliar sprays use a processed form of organic neem oil insecticide known as clarified hydrophobic neem oil. 

Neem oil is safe to use on ornamental and edible plants. It can be sprayed on all kinds of fruits, shrubs, fruit trees, vegetables, and edible flowers.  

Some neem oil mixtures are labeled “ready to use” and often come in a spray bottle you can use to apply them. Make sure to spray the undersides of leaves where pests can hide and lay eggs. 

Misting houseplant leaves with spray bottlePin
Photo Credit: Instagram @marphylco

 Sprays containing neem oil extract are also used to treat fungal and bacterial diseases such as anthracnose, black spot, blight, botrytis, fire blight, powdery mildew, rust, and scab.

This oil has most of the active ingredients of Azadirachtin removed, resulting in concentrations of .5% to 3% percent.

As a topical solution, neem foliar sprays suffocate insects on contact and kill some external fungal diseases and infections.

Related: More on How Neem Oil Insecticide Works on Plant Pests

But, it requires application every other day for at least 14 days for it to work.

Apply at either dusk or dawn to prevent contact with beneficial insects such as ladybugs or honeybees. It won’t harm birds, but it’s toxic to fish and other aquatic creatures. 

Avoid harming beneficial insects and water habitats by applying the spray carefully and following all label directions for application. 

Once you end any current infestation, you can safely use the foliar spray once every two weeks for prevention.

Related: Read the Do’s and Don’ts When Applying Neem Oil Sprays.

How Often To Use Neem Soil Soaks

Soil soaks or a Neem drench is a very different story.

The soaks use 100% percent cold-pressed pure (AKA raw) neem oil.

Pour this version of neem oil for indoor plants on the soil so the plant’s roots can soak it up, turning it into a systemic insecticide.

The Azadirachtin will remain potent within the plant for up to 22 days. It will only affect piercing or chewing bugs.

It makes it far safer for use on houseplants near beehives.

Due to the longevity of the Azadirachtin, repeat soil soaks every 21 days to keep the potency.

Azadirachtin kills most infestations without harming pollinators and beneficial critters such as earthworms or predator species. But it will also help combat many bacterial and fungal infections, including some forms of root rot.

When NOT To Use Neem Oil

Something not discussed enough is when you shouldn’t use neem oil on a plant.

While non-toxic and often used in products such as toothpaste, it’s generally agreed that you should not apply neem to an edible plant on the day of harvest.

Hose spraying with attachment on plants.Pin
Photo Credit: Instagram @holmangarden

You can use a foliar spray the day before or soil soaks before harvest. You will ingest less if you avoid applying it on the actual day of harvest.

Don’t use neem oil in the middle of the day because the direct sunlight and neem oil together can burn the plants. 

Another essential rule is constantly testing a small part of a plant one day before using neem oil products.

Plants, like people, can have or develop allergies and sensitivity to even natural products.

By testing a small portion of the plant first, you can check for signs of chemical burns or allergic reactions.

When using Neem regularly, you may only need to test once. Yet you should always retest the plant if you haven’t used neem oil on it for an extended period.

If you see an adverse reaction from testing or regular use, you should stop using neem products on that plant immediately.