How Do You Use Neem Oil On Houseplants?

There’s nothing worse than going to water a prized plant only to find it’s infested with bugs.

There are fewer houseplant pests than what you might find in your garden, but these indoor plant pests tend to be highly aggressive. 

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Janet Craig Dracaena used as houseplants at Disney World Resort | PlantCareToday.com

One of the biggest issues with using a chemical solution for indoor plant pests is the concern for humans, cats, or dogs.

Thankfully, neem oil products are a form of natural pest control that is generally non-toxic to humans and animals.

Created by crushing portions of Azadirachta indica, organic neem oil is used in medicine, healthcare products, and as a natural pesticide.

Neem can be purchased in a number of ways, from neem oil concentrate to raw or clarified neem oil, and even as a pre-mixed neem oil spray.

While neem is generally safe, it should always be diluted to avoid injuring your plant due to the natural chemicals it contains.

How To Use Neem Oil On Houseplants

There are three ways to employ neem oil insecticide control with your indoor plants:

  • Neem cake
  • Neem soil soak
  • Neem oil spray

These methods can be used to not only get rid of common pest infestations, but prevent them from occurring in the first place.

Neem Cakes

One of the most beneficial sources of neem oil is neem cakes.

Consisting of the solids left over from extracting raw neem oil, neem cakes contain a small amount of Azadirachtin-rich oil, as well as many nutrients.

The cakes are commonly used as a natural antibiotic for livestock and a natural compost fertilizer for plants.

Neem cakes are most effective against grubs and insects which like to burrow into the soil around your plant.

It also helps prevent fungal infections such as root rot and can be used to help plants recover from these infections.

To use, simply take a neem cake and break it up into the soil of your houseplant.

Be sure to follow any instructions to avoid overfertilizing your plants.

Neem Foliar Sprays

By far, the most popular way to apply neem oil is through the use of a foliar spray.

Neem-based sprays can be used to combat pests, as well as serving as a leaf shine.

The topical application of neem oil results in a contact poison that quickly dissipates, leaving behind no residue.

Outdoors, you should only spray the plant at dusk or dawn to avoid harming beneficial creatures, but there are no such restrictions for indoor plants.

Foliar sprays use clarified hydrophobic neem oil, which has had most of its Azadirachtin removed, leaving only a .5 to 3% percent concentration behind.

To make a quart of neem oil spray, you will first need to emulsify some water so the oil can mix.

To do this, simply stir ⅓ teaspoon of Dawn dish detergent into the water.

Add in 1 teaspoon of clarified hydrophobic neem oil and blend well, then pour into a dedicated spray bottle.

Note that it’s usually best to start off with .5 or 1% percent, as these provide the least risk of burns when overapplied.

Test the spray on a single leaf 24 hours before performing your first full treatment to ensure the plant isn’t allergic.

Once you confirm the tested leaf hasn’t had a reaction, you can begin to treat the entire plant.

Spray every single leaf thoroughly, getting the tops, bottoms, and any crevasses where it connects to the main stem.

When you spot a bug, douse it.

The oil will evaporate in 45 minutes to an hour after application.

You will need to repeat this treatment every 2 days for up to two weeks.

Note that neem oil can take time to start really working, so don’t expect a clear plant after only a few applications.

Once your plant’s bug-free, you can add new treatments every 14 days as a preventative measure.

Neem Soil Soaks 

In its purest form, 100% percent raw neem oil is a potent toxin with five different natural insecticidal chemicals.

When properly cold-pressed, raw neem oil is the ideal choice for soil drenches, as it will kill grubs and harmful subterranean bugs without harming beneficial bugs or earthworms.

Indoors, the benefits can be even more pronounced, as the roots absorb neem from the soil, turning it into a systemic insecticide that affects any pest biting into the plant.

It also helps fight off bacterial and fungal infections by boosting the plant’s immune system.

Related: Using Neem Oil as a Fungicide on Plants

Making a soil drench is a little different than a foliar spray.

You will still need to begin with an emulsion, this time with 1 teaspoon of pure castile soap added to a gallon of water.

Blend in 2 tablespoons of 100% percent cold-pressed raw neem oil.

Pour 2 to 3 cups of the mixture directly onto the soil around your infested plant.

The Azadirachtin remains in your plant for up to 22 days, although its effects might not be immediately noticed.

This is because the chemical closely resembles insect hormones that regulate growth, development, and appetite.

More on How Neem Works on Plant Pests

Rather than outright killing the bugs which ingest it, Azadirachtin arrests their development, causes infertility, and will slowly starve the pest.

Once the infestation is gone, you can provide your plant with preventative treatments every 3 weeks to help it stay healthy.

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