Most people who garden have heard of using neem oil on plants. But what exactly is neem oil, and is it safe to use on yourself and your family? How can you use it, anyway?
We have a number of non-toxic tools that can help us fight pests and diseases that destroy our greens. Neem oil can kill bugs including aphids, scale, fungus, and molds such as root rot and sooty mold. Likewise, it is safe for both humans and most domesticated animals, and it won’t harm beneficial insects like bees and parasitic wasps. You can use it all over your garden, orchard, indoors for houseplants and outside in greenhouse environments.
We have all the details you need to know about using this powerhouse in the garden.
What Is Neem Oil?
Azadirachta indica (neem) is an Indian lilac that is commonly grown in areas of southwest Asia such as India and Southeast Asia. Its oil is extracted by pressing the leaves.
Neem trees produce fruit, and those seeds are pressed to extract the oil, which is used in cosmetics, pesticides, and other products. Its active compound is azadirachtin, but it also contains healthy fatty acids and omega 3’s.
A range of colors are available in neem oil, including yellow, brown, and red. It has an anise-like odor, similar to garlic with a hint of sulfur.
How to Use Neem Oil for Plants
Azadirachtin’s active ingredient deters insects and disrupts the insects’ hormone systems. This prevents them from feeding and developing, making reproduction difficult. It is not a pesticide that kills bugs by contact. It works over time.
The natural insecticide neem oil is not a knockdown killer, but it is definitely worth including in your overall gardening plan. Neem oil can be bought or made at home.
You can find organic neem oil, which tends to contain higher levels of the active ingredients. You may also want to avoid commercial sprays, since many of them may contain less desirable ingredients. Don’t worry; making your own spray is simple.
This recipe works well:
- One teaspoon neem oil (use pure, cold pressed oil)
- One-third teaspoon of insecticidal soap or liquid detergent
- One quart of warm water
Here’s what you need to prepare:
- Mix the warm water with the soap.
- Slowly add the oil and stir to mix.
- Pour mixture into a sprayer.
- Keep shaking or otherwise agitating the mix while spraying.
Only make as much as you can use right away.
Neem Oil as a Pesticide
Probably the most important use of neem oil for plants is as a pesticide. It is found in many forms, including granules, powder, and liquid. Whiteflies, flea beetles, caterpillars, mites, and aphids are among the insect pests killed and repelled by neem.
Despite its popularity among farmers to use it on vegetables, you can also use it on landscape plants and lawns. Want to get rid of Japanese beetle grubs in your lawn? Spray your neem mixture onto the grass and soak bare spots.
The herb Neem is considered a natural insect repellent that is safe for pollinators like honey bees, butterflies, and ladybugs.
Neem Oil As a Fungicide
Besides being an excellent fungicide, Neem oil can also protect your plants from many kinds of fungi, including powdery mildew, anthracnose, leaf spot, rust, and scab.
This fungus prefers warm, humid conditions and damages plants during summer, so powdery mildew is especially problematic. You can identify powdery mildew by the white or gray spots it causes on your plants’ leaves. Fruits and vegetables susceptible to powdery mildew should be sprayed every two weeks.
Neem Oil as a Dormant Spray
Neem oil can be used as a dormant spray on your orchard’s plants, which you spray on trees during their dormant period, often in cold weather. Typical dormant insects include mites, scales, and woolly aphids. These sprays make it easier to remove dormant insects and their eggs.
Neem Oil as an Organic Fruit Tree Spray
As a fungicide, I also use fish emulsion and kelp in combination with neem oil during the growing season.
Apply this combination when:
- Green leaf tips emerge in spring.
- After buds first turn pink.
- Petals fall.
- About one week after the petals fall.
After harvest, spray the tree as usual, but also spray the ground to promote leaf decomposition and kill any insects hiding under it. After about half the leaves have fallen from the tree, apply fish emulsion and neem oil, but omit the kelp.
Neem Oil as Bacteria Control
As well as controlling fire blight, neem oil helps control bacteria on fruit trees. During the dormant season, spray the trunk, branches and canker areas with neem oil.
There was a situation where I had fire blight in my apples, particularly in the Honey Crisp variety. I used neem oil and other organic sprays, including Serenade and sulfur. However, nothing worked, so I started focusing on varieties with more resistance.
How To Apply Neem Oil for Plants
The best way to use neem oil for plants is to spray it on the leaves. It kills insects that feed on the leaves after they have been sprayed. Neem oil can decompose quickly, so you may need to spray weekly to control pests.
It is recommended to spray during times of bug activity, often in the morning or evening when insects emerge from hiding places in search of food.
In addition to not spraying too heavily, you should also wait at least 24 hours before spraying a large amount. Neem oil can kill plants if applied too heavily. If applying neem oil in the direct sun or when the temperatures are very hot or cold, please take extra care with young seedlings and young plants, which tend to be more sensitive than older ones.
This method doesn’t work for all plants and pests, though, so make sure to check if it will work for your particular problem. You can also apply neem oil to the soil. The plant absorbs it through its roots, along with the poison.
Sunlight and microbes rapidly break down Neem oil, which has a lifespan of 1-2 days on the plant. Another benefit is that insects don’t become immune to the oil, which means it can be used repeatedly. Spray bottles, hose sprayers or watering cans can be used to apply neem oil.
Is Neem Oil Safe?
Neem oil is not only generally safe for use in the garden, but it can also be used as a foliar fertilizer due to its fatty acids. Neem cakes are also used as soil conditioners.
Although neem oil doesn’t harm beneficial insects which typically do not feed on plants, it can harm critters that feed on plants that have been treated. It is safe for mammals and birds, but some tests show that it can cause toxicity in fish.
For plants, neem oil is a great solution, but can it also be used safely on humans? Neem oil is safe to use topically. Nonetheless, it is not recommended for use on pregnant women. Neem seeds are toxic if consumed directly.
For some people, neem oil can irritate their eyes and skin, so wash products that have been sprayed with it before eating them and wear gloves while applying. The FDA says it is not a recognized carcinogen.
Neem oil has a multitude of uses in India, including cosmetics, soaps, and lotions. Thanks to its anti-aging properties and antioxidants, neem oil is touted to be effective in preventing aging and moisturizing skin. In terms of cosmetics, the oil has been stripped of Azadirachtin and left with hydrophobic oils, which aid in skin conditions such as eczema or psoriasis. This oil has also been used as a hair conditioner.
It’s safe for dogs, horses and cats to use neem oil for flea and mosquito control. However, some cats have an adverse reaction to neem in flea control products, so exercise caution.
Neem Oil Around the House
For ants, termites, and other household pests, Neem oil works well. However, It is not much effective against cockroaches. After you spray termites with a pesticide, spread neem dust around the wood where they are eating.
We expect neem oil to play a key role in pest management in the home and garden in the coming years. It’s effective, safe, affordable, and easy to use – what more could you want?