Does Neem Oil Work As A Fungicide On Plants?

Is Neem oil a fungicide? We know Neem is the go-to natural insecticide in most parts of the world due to its minimal effect on the environment and low to nonexistent toxicity for humans and pets.

Extracted from various parts of Azadirachta indica, an ornamental tree related to mahogany, the oil and solids contain a natural insecticidal chemical called Azadirachtin.

This is a natural insecticidal chemical that is known to possess antifungal properties.

Gardener spraying plants for fungus with Neem oilPin
Spraying plants for fungus with Neem oil | focusandblur-DepositPhotos

Neem oil works wonders in fighting a range of fungal infections on plants and harmful pests such as spider mites, aphids, Japanese beetles, scale insects, and whiteflies.


Whether used as a neem soil drench or foliar spray, neem oil interrupts the life cycle of harmful pests and can sometimes kill them outright, yet won’t harm pollinators or beneficial insects that don’t come into direct contact with the oil.

But merely knowing you can kill common plant pests such as aphids with neem may not be enough for some houseplant enthusiasts who discovered the honeydew has led to a fungal infection.

Fear not, because the same treatment you use to kill the aphids may also cure your plant.

In this article, we’ll dive deep into all the details about neem oil for fungus on plants.

Does Neem Oil Kill Fungus On Plants?

Does neem oil help with fungus? People often ask this.

Neem oil is a natural byproduct of the neem tree. The oil is harvested from the trees’ seeds and leaves.

Many people wonder, is neem oil a fungicide? The answer is yes! Neem oil has antifungal properties and can effectively treat various fungal infections on plants.

Considering neem oil as a fungicide is a wise choice due to its natural properties. It can effectively control and prevent various fungal issues in plants.

Neem oil on plants not only acts as an effective fungicide but also gets rid of pests that create honeydew, which can encourage fungal growth.

It even kills many bacterial infection forms, making it one of the best all-around remedies for your plant’s health.



Neem seed oil works all through the growing season because it can kill pests at every stage of their life cycle, including when they are eggs, larvae (grubs), pupas, and adults. 

neem oil for fungus? What Fungi or Diseases Does Neem Oil Kill?

Neem oil can help protect against a large number of fungal infections and some diseases and virii.

Some of the conditions neem oil helps treat include:

Neem oil fungus has also been successful when proactively treating seeds against phytopathogenic fungal diseases.

How Effective is Neem Oil against Fungus?

Using Neem oil for fungal infection can be an effective solution. It acts as a natural fungicide and can help control fungal issues in plants.

As with any product, neem oil works best when used as a preventative, and its effectiveness will decrease the longer you wait to treat an existing infection.

Surprisingly, neem oil as fungicide is thought not to harm certain beneficial insects, including ladybugs and predatory mites, and does not impact honey bees and other pollinators like butterflies as long as they’re not sprayed directly. 

For example, a neem foliar spray will eradicate a new sooty mold infection in as little as a few days but may not be able to save an entire plant from an advanced case of rot.

Neem Oil Fungicide and Pesticide Recipe – Making an Antifungal Foliar Spray and Soak

Here’s how to use neem oil for fungal infection:

Take a gallon of water and slowly blend in 1 tablespoon of pure castile soap to serve as an emulsifier (i.e., it allows the water and oil to mix).

Now add 4 teaspoons of 1% percent clarified hydrophobic neem oil to make a foliar spray or 2 tablespoons of 100% percent cold-pressed crude neem oil for a root soak.

Both of these mixes will have their target areas and benefits, so you may wish to use only one or a combination, depending on the situation.

Foliar sprays are purely topical and evaporate in an hour or less, leaving behind no residue.

This option not only targets any visible fungus but will also kill aphids, mealybugs, plant scales, and other insect pests that produce honeydew. This substance attracts sooty mold and other fungal infections.

Meanwhile, root rot and other subterranean fungal issues will require a soil soak.

Soil soaks are also absorbed by the plant, turning it into a systemic insecticide that lasts up to 22 days and can also cause an immune system reaction in the plant that helps eliminate fungal infections that have entered the plant itself.

How to Use Neem Oil as a Fungicide

Treating fungus with neem isn’t much different than fighting plant pests, and some of the same cautions apply.

Clarified hydrophobic neem oil is the active ingredient in ready-to-use neem oil sprays that can be picked up at a garden center. 

Apply the mixture to your plants. Use a foliar spray bottle to apply your neem oil mixture to one small section of your plants. Wait twenty-four hours.

Only use the foliar spray at dusk or dawn to be gone before pollinators and beneficial insects become active.

Treat the planet as soon as possible, and be aware that even the best efforts may not be enough for a plant that’s already nearly dead.

For use on a variety of plants in your lawn and garden, including roses, flowers, houseplants, ornamental trees and shrubs, fruits, nuts, and vegetables. 

Always test a neem product on a small portion of the plant 24 hours before treatment begins, as plants can have sensitivities or allergies, just like humans.

Finally, saplings and new growth are often very tender and highly susceptible to chemical burns, so avoid using neem oil on those plants/areas if possible.

Neem is also used in Powdery Mildew Control.