How to Use Neem Oil Spray as an Organic Insecticide

Adam Taylor2 weeks ago

0 23,002 4 minutes read

Neem oil spray is an organic solution used as a pesticide against insects, mites, or fungi bothering your plants. It is used medicinally, in the cosmetics industry, and as an organic insecticide spray.

Organic gardeners love that the oil is safe to use, and it will not harm humans or animals. It’s even safe for most wildlife since its insecticidal properties are targeted to specific pests that damage garden plants.1

You can buy commercial neem oil solutions, but they may be less potent than homemade versions. Read on to learn how to make and use a neem oil mixture against certain insects so your plants can thrive.

What Is Neem Oil?

Neem oil is a naturally occurring pesticide found in seeds from the neem tree with a hundred-plus-year history of controlling pests and diseases. The active ingredient in the oil is azadirachtin, which repels and kills pests.1

When and Where to Use Neem Oil

Neem oil is safe for the environment. If you have a bad infestation, apply the neem oil solution to the stems, leaves (including the undersides), and soil. Microbes and light quickly break down the pesticide in soil, water, and leaves.1

Spray neem oil on foliage in the morning or evening when beneficial bugs are dormant and not feeding or pollinating.
While many pesticides can only be used at certain times, you can use neem oil throughout the planting season.
Neem oil is effective at any time during a season, because it affects insects during all phases of their development.2

However, you should avoid using the spray in the middle of the day when the sun and heat could burn the sprayed foliage. You should also avoid spraying neem oil if rain is forecasted in the next 24 hours since it could wash away.

How Does Neem Oil Work?

Neem oil interferes with the normal life cycle of insects, including feeding, molting, mating, and egg-laying.2

Neem oil controls hundreds of pests, including whitefly, aphids (pictured below), Japanese beetles, moth larvae, scale, and spider mites.
Neem oil is also listed as a miticide because it kills mites, which are not insects but are related to spiders and ticks.
Sprays containing clarified hydrophobic neem oil extract are also used as fungicides against rust, black spot, mildew, leaf spot, scab, anthracnose, blight, and botrytis.

Warning

Neem oil does not harm birds, but it may harm beneficial insects and soil-loving creatures, such as bees, butterflies, lady beetles, and earthworms.3 For that reason, it should only be used when you have a definite issue with one of the harmful insects.

[better-ads type='banner' banner='2246' ]

Equipment / Tools

Garden sprayer
Spray bottle (optional)
Protective gloves (optional)

Materials

1 to 2 tablespoons neem oil, pure or raw form, cold-pressed
1 gallon water
1 to 2 teaspoons mild dish detergent

Instructions

Mix the Detergent and Water

Add 1 to 2 teaspoons of dish detergent to 1 gallon of warm water in your sprayer. Mix thoroughly.

Neem oil will not readily combine with water and needs an emulsifying agent, like a mild dish detergent, to effectively mix the oil.

Tip

Diluted liquid soap works as a homemade garden pesticide. It also kills aphids and other soft bugs when sprayed directly on pests.
Add Oil to the Detergent and Water

Slowly pour in 1 to 2 tablespoons of neem oil after you’ve combined the detergent and water. Mix thoroughly.

Warning

Adding too much neem oil to your mixture may cause leaves to burn if they are in direct, harsh sunlight most of the day. Do not add any more than is needed.
Spray the Solution

Spray all plant surfaces (including tops and undersides of leaves) until completely wet and dripping. Use protective gloves to avoid any oily drips.
Reapply Regularly

Apply the oil mixture every seven days.4 As a preventative measure, neem oil should be applied to all the plant surfaces on a seven- to 14-day schedule, according to manufacturers, such as Bonide.

Using Neem Oil Spray in Trees

Certan trees can highly benefit from neem oil. For example, flowering dogwood trees (Cornus florida) are highly susceptible to powdery mildew.5 Because powdery mildew is a fungus, the fungicidal properties of neem oil can help fight this.

Blue Star juniper (Juniperus squamata ‘Blue Star’) can succumb to infestations of spider mites.6 Take advantage of neem oil’s miticidal properties to kill spider mites on the tree.

Additionally, spraying Colorado blue spruce trees (Picea pungens) with neem oil can work as an insecticide against Cooley spruce gall adelgids and aphids.

Tips for Using Neem Oil

Avoid spraying new seedlings with neem oil, or they could also burn.
Make small batches of neem oil spray the same day you intend to use it, or your mixture will become thick over time.
Try a liquid peppermint soap as your emulsifier, or add a few drops of peppermint essential oil into the mixture, because the fragrance itself is also a bug repellant.
Test neem oil on a single leaf before using it for the first time on plants that need treatment. Check for signs of stress after a day to be on the safe side. If all is well you can proceed.
FAQ
- What are the disadvantages of using neem oil in your garden?
  
  When used incorrectly, neem oil can actually burn your plants’ foliage. Additionally, neem oil can harm beneficial insects.
- Are there any plants you should not use neem oil on?
  
  You should avoid using neem oil on hibiscus, carnation flowers, fuchsia, and impatiens, as well as some trees including maples, junipers, redbuds, and spruces.
- What other organic insecticides can you use instead of neem oil?
  
  Other organic insecticides include diatomaceous earth and a spray made peppermint, rosemary, and thyme oil.
- Is neem oil pet safe?
  
  Yes, neem oil is pet safe. However, exposure should be limited when possible.

Adam Taylor2 weeks ago

0 23,002 4 minutes read

How to Use Neem Oil Spray as an Organic Insecticide