Ultimate Guide: Growing and Making Your Own Neem Garden Pesticide

Green shade neem tree

The extensive wonders of neem have not gone unnoticed by gardeners in recent years. 

The neem tree (Azadirachta indica) is best known for its oil – an effective and safe herbicide. There’s a lot more to this versatile plant, native to Asia and India that makes it so special.

In Sanskrit, neem oil is known as Sarva Roga Nirvani or “cure of all ailments” and we daresay it lives up to the name. 

Read on to learn more about neem trees, how to grow and care for them as well as their uses and benefits for your garden.

How to Grow the Neem Tree

Neem Tree
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Growing neem trees can be a fun and easy task thanks to the climatic conditions they require. They have vast climatic adaptability. As such, they can thrive under arid, semi-arid, and sub-humid conditions. 

If your area meets these standards, then growing neem is too good an opportunity to pass up. 

These trees are hardy and have the ability to tolerate temperatures as high as 120°F (50°C). The drawback to this is when temperatures fall below 35°F (5°C) which causes the leaves to drop from the tree. 

Neem does not tolerate extended cold, frost, wet climates, or drought well. Regardless, you can grow a tree indoors in a container full of high-quality potting soil. All you need is fresh seeds to start with.

If you prefer to grow them outdoors, plant the seeds directly in the ground. You can also start with trays then transplant later, in about three months. When dealing with mature trees, be sure to root the cuttings in early winter or late fall. 

Neem trees grow best in USDA hardiness zones 10 through 12. They can live for 200 years and grow 50-75 feet tall.

How to Care for the Neem Tree

When caring for neem trees, the key growing conditions to consider are:

  • Sunlight
  • Moisture
  • Soil type
  • Pests and diseases

Neem trees need lots of bright sunlight as they are heat-loving plants. With the right amount of warmth and sunlight, the faster they grow in the long run. 

You also need to water them regularly, but be cautious not to overdo it. Your tree will have a hard time growing in poorly drained soil and won’t tolerate wet feet. One trick is to ensure you let the soil dry between every watering session. 

Neem trees can grow in a variety of soils be it sandy or clay, alkaline, or saline. For best results, black cotton soils or well-drained soil that have subsurface water are the way to go. Sadly, neem trees don’t do well in pots as they are quite vigorous and pots are very restricting

This doesn’t mean it’s impossible. When growing a neem house plant, just be sure to give it warmth, lots of sunlight and remember not to overwater it. 

Neem trees have an extensive root system. This gives them the ability to extract nutrients from leached sandy soils. Moreover, neem trees can grow and adapt to a vast array of landscapes. They can, therefore, help combat landslides and erosion in your garden. 

Can you believe that even neem trees’ fallen leaves serve a purpose besides mulch or fertilizing soil? That’s right. They can neutralize acidic soils too!

Another great benefit to growing neem trees is their pest-free reputation.  they are not completely invincible to some insects and diseases. 

Be on the lookout for the following when growing neem trees:

Phyllocoptes sp
Powdery mildew
Spider mites
Root rot
Leucaena psyllid
Bacterial blight
Homoptera coccidae

Related: Best Weed Burners for EcoFriendly Weed Killing

Neem oil
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Steps to Making Your Neem Pesticide

If you want to use neem oil in your garden, there are two ways to go about it. You can either buy commercial neem oil gardening products or make your own neem oil spray. 

Buying commercial neem oil products has its benefits. These products are (regularly) well tested and safe to use. Buying a ready-to-use product is also more convenient than mixing the ingredients yourself.

There’s always a catch though. When it comes to store-bought neem oil products, they may contain less azadirachtin. This lowers their effect on pests. 

Making your own pesticide from pure oil ensures you add in the right amount of azadirachtin. You also get to steer away from additional compounds that are unnecessary in your garden.  

As you make your own DIY neem oil spray you enjoy some benefits such as:

  • Choosing the concentrations and ingredients that would best suit your garden 
  • Tweaking the formula based on past experience and observations in your garden

For example, you can experiment on your plants by using lower or higher neem oil doses. You can also monitor the effect that has on common insects you have spotted on your plants.

Before you get started, it is important to be cautious when making your own DIY sprays. Various plants can have different reactions to home-made solutions and not all of these reactions turn out great. 

The general rule of thumb to tell whether your spray is up to par with other products is to conduct a test run first.

Step 1 – Find a Base 

To start off, use a base of neem leaf extract or good quality neem oil. Seek out 100% pure oils also known as crude or raw neem oil. 

Make sure the base is cold-pressed as heat will destroy the azadirachtin. Another alternative is organic neem oil. It undergoes no contamination during the purification process with petrochemicals.

Step 2 – Emulsify

It is important to totally emulsify the neem oil before you add it to the water seeing as oil and water don’t mix. 

If it fails to emulsify well, the neem will be uneven and come out globby on your plants. 

This makes your neem oil spray less effective. It also increases the damage risk to some areas of your plants that receive heavier doses. In some cases, your plants can get sunburnt due to this imbalance. 

Take note that overtime, neem oil attempts to re-separate from the water. This occurs even if it was properly emulsified at the time of use. 

If you have a large batch and want to store it for a long period of time, make sure you shake the container thoroughly. This will ensure it remains mixed prior to use. Emulsifying agents that allow neem oil to mix with water are soap or silica.

Step 3 – Time to Mix

How much detergent should you use per gallon of water?

Here’s a simple recipe. 

To make a gallon of neem oil spray, mix 4 teaspoons of neem oil, 1 teaspoon of liquid dish soap, and 1 gallon of warm water. Be sure to add the soap to the water first and stir in the neem oil right after. 

If your preferred choice is silica power as an emulsifier, the easiest thing to do is pre-mix a portion of the power with water and store it as a liquid solution. 

This way it stays ready to use, as long as you add in the neem oil whenever you need it. For this task, fill a container with 8 ounces of water and add 35 grams of silica powder to it. 

Then mix it thoroughly and store for up to a year in a cool dark place.

Step 4 – Spray

If you’d prefer not to get oily or have sensitive skin, it’s great to take precautions as required. When applying neem oil spray on your plants wear gloves. 

Pour your mixture into a spray bottle and use within 8 hours before the ingredients start breaking down. 

We advise you to refrain from using neem oil on small seedlings as it could burn and damage then. Plants that are close to a month or two old can handle it. That’s if you start off with slightly less than a tablespoon of neem oil per gallon.  

You don’t have to fret over large, mature plants as much – feel free to use the complete neem oil recipe.

Foliar sprays are most effective when used just after the sun goes down. There are two main reasons for this:

  • At this time, the insects beneficial to your plants are less likely to be active and present then
  • Your neem oil spray has enough time to seep into the plants and dry a bit 

Be sure to fully drench your plants with neem oil spray until the leaves are dripping. Don’t forget to spray the underside of all leaves as this is where most diseases and insects hide! 

Watch the video below for more information:

How to Use Neem Oil in Your Garden

Neem oil is a non-toxic, safe to use pesticide that leaves no dangerous residue in your garden. It is also one of nature’s favorites when dealing with problem insects. The seeds, fruits, and bark of the tree all have important uses.

Neem Tree
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Neem oil spray is most effective when applied to young plant growth. It complements other measures such as using fertilizer and a weed remover

When placed in soil, neem oil has a half-life of 3 to 22 days but this greatly decreases in water by lasting 45 minutes to four days. 

It is often recommended for gardeners to use neem oil sprays as a preventative care routine rather than cure as it works better that way. Alternatively, it can be used at the first signs of disease in conjunction with other pest control methods to bolster the effort. 

Using neem oil is nearly non-toxic to fish, bees, birds, and wildlife. Studies have shown no diseases such as cancer arising from its use. This makes neem oil safe to use if you also have poultry or livestock in your garden.

How Does Neem Oil Work as a Pesticide?

According to the National Pesticide Information Center, “Neem oil is made of many components. Azadirachtin is the most active. It reduces insect feeding and acts as a repellent. It also interferes with insect hormone systems, making it harder for insects to grow and lay eggs.”

Furthermore, according to the University of Connecticut, “ Adults are not killed by the growth-regulating properties of azadirachtin but mating and sexual communication may be disrupted which results in reduced fecundity.”

Use neem oil as a foliar spray for all hydroponic and indoor growers to prevent fungus and insects. 

When Should You Apply Neem Oil?

Does your eggplant or squash have holes appearing on the leaves? Have you spotted small insects crawling over your plants in the garden? Perhaps it’s those pesky fungus gnats flying all over your indoor seedlings?

If your answer is ‘yes’ to any of the above, it’s time to use neem oil spray on your plants. 

If you have an infestation of pests, apply neem oil to your plants every 7 days until it clears up. Be patient and remember that neem oil is a natural organic product: it will take some time to get rid of the bugs. Consistency is key!

Be mindful of the weather forecast as well when applying neem oil. If any rain is predicted, reschedule your application for another day. This is because the neem oil will be washed away by the water and lose its effectiveness. 

How Often Should You Use Neem Oil?

The rate at which you choose to use neem oil will vary based on:

  • Your schedule
  • Your situation
  • The severity of the problem is

Neem oil should not be applied more than once a week, but it also lacks a long-lasting residual effect. 

For plants you aim to protect regularly, such as artichokes, you can spray them weekly or every other week for optimum results. This can also be applied to plants exhibiting signs of disease or insect infestation.

Which Pests and Fungus is Neem Oil Effective Against?

Oil from neem trees is an all-time favorite for organic gardeners in the United States. Neem oil works well against various pests and insects such as:

  • Fungus gnats
  • Whiteflies
  • Aphids
  • Mealybugs

Furthermore, neem oil won’t harm any beneficial insects in your garden. Examples include ladybugs and butterflies. That’s because most of these insects don’t bite the plants. Their larvae might end up smothered in neem oil sprays nonetheless. 

Using neem oil is also useful when treating fungal diseases such as sooty mold and black spots. 

What Can I Use Neem Oil For?

Gardeners enjoy being able to fully capitalize on their produce. Neem trees are a gift that keeps on giving and there are many ways to make the most of them. 

From a home remedy to a natural pesticide, neem oil meets certain demands otherwise met by dangerous chemicals. 

Below is a list of all their purposes and usage in today’s market:

  • Fodder for your garden
  • Pesticides
  • Wormicide
  • Cosmetics
  • Medicinal
  • Toothpaste
  • Anti-desertification
  • Farm tools and furniture

Related: Trees and Your Environment

Make Informed Decisions With Clean Air Gardening

Now that you know all about the wonders of neem trees, growing them will be a piece of cake! 

All you’ve read about neem oil is only the beginning. It doesn’t have to end there. Seeking to improve your garden in an environmentally friendly way? At Clean Air Gardening, we are well-equipped to guide you on this journey. 

We’ve been at this since 1998 and find it rewarding to help people create their own oasis by providing lawn and garden supplies. 

Stay up to date with all the latest trends and updates in the gardening world. With Clean Air Gardening, you’ll have all you need to improve your eco-friendly experience.

Featured image: Pixabay by Guddanti

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