Sasha CampbellNeem oil is a natural remedy for controlling a wide range of pests. It is a natural pest control solution with many other benefits and uses.
Neem oil comes from the seeds of the neem tree (Azadirachta indica), a tropical evergreen tree [1].
It reduces insect feeding and disrupts insect hormone systems, making it difficult for them to lay eggs and grow. It may also help deter some pests from feeding on treated plants.
The Benefits of Using Neem Oil on Plants
Neem oil is a natural fungicide and insecticide used in a wide variety of garden and home products.
It can control various insects and fungal diseases, helping reduce pest and disease problems in the garden.
Additionally, the deoiled residue (neem cake) from crushed neem kernels is widely used as an organic fertilizer [2].
Below are the main benefits and uses of this remedy in the garden.
1. Treatment of Bacterial and Fungal Disease Issues
Many gardeners use it to help prevent and manage fungal and bacterial plant diseases. It has antifungal properties and may help suppress certain plant pathogens.
Neem oil is most effective against powdery mildew, black spot, rust, anthracnose, and some leaf spot diseases. It may also help suppress some bacterial problems when used preventively.
Regularly spraying neem oil solution on plants in and around the garden can help control many bacterial and fungal problems.
2. Control Pests
Neem oil can also help control many pests that destroy food crops and other plants.
Neem oil pesticides are often the first choice for organic gardeners. They are effective against many types of destructive bugs and pests and can be applied in several ways.
A spray solution applied around plants and directly on leaves can kill some pests. It can also suppress others by disrupting their feeding and development. Additionally, it helps deter certain insects from feeding on the plants.
Some garden pests that neem oil works against include:
- Caterpillars
- Leaf-footed bugs
- Leafhoppers
- Aphids (greenflies)
- Spider mites
- Lace bugs
- Fungus Gnats
- Leaf miners
- Some beetles
- Some soil-dwelling larvae
- Spotted lanternflies
- Tarnished plant bug
- Mealybugs
- Whiteflies
- Squash bugs
- Grasshoppers
- Locusts
Moderate neem oil applications can benefit the soil. They may help reduce certain plant-parasitic nematodes while having little impact on earthworms.
3. Natural Fertilizer (Neem Cake)
Neem oil itself is primarily used for pest and disease management.
However, neem cake, which is made from the residue left after oil extraction, is widely used as an organic fertilizer and soil amendment [3].
4. Glossy Foliage
When used correctly, neem oil sprays leave foliage healthy and looking glossy.
Neem oil can be used to clean indoor plant leaves, particularly in enclosed spaces such as greenhouses.
Dampen a rag, then wipe the top and bottom of each leaf with your DIY solution (recipe below).
How to Use Neem Oil in the Garden
Be careful when using it, as it may irritate sensitive skin and the eyes.
Make a homemade neem oil spray by combining 5 ml of neem oil, 2 ml of organic liquid soap, and 1 liter of water. Shake well and spray both sides of the plant leaves.
Alternatively, purchase a neem oil concentrate online or at your local garden center. Use it according to the label’s instructions.
For prevention, apply every 7 to 14 days as needed. During active infestations, applications may be repeated every 7 days as directed on the label.
However, do not use neem oil in hot weather, as it will likely cause foliage burns. It can also damage newly transplanted or stressed plants. Apply neem oil in the early morning or evening to reduce the risk of leaf burn.
Spraying in the spring and other suitable times throughout the year can target the eggs and larvae of various pests.
To wipe down houseplant leaves, mix one teaspoon of neem oil with ½ teaspoon of liquid soap in 1 liter of warm water. Use this solution to wipe down the plant leaves to achieve a glossy shine.
Ingredients
Neem oil contains several naturally occurring compounds that contribute to its pest-control properties.
One of the best-known compounds is azadirachtin. This component is toxic to some pests, disrupting their molting process.
Other active ingredients include picrin, nimbin, and sialin [4].
What Plants Not to Use Neem Oil On
Some plants are more sensitive to neem oil than others.
Some herbs, including thyme, cilantro, oregano, parsley, and dill, may be more sensitive to neem oil. Test a small area first before treating the entire plant.
It can also cause leaf burns when used on leafy vegetables such as lettuce, spinach, and arugula. Moreover, neem oil may coat the delicate foliage of some ferns, increasing the risk of leaf damage.
High doses can burn plant leaves. Therefore, read the label carefully to see if there are any restrictions.
Avoid applying neem during hot weather or on stressed plants.
How It Affects Beneficial Insects
Neem oil insecticides control bugs and pests that feed by sucking or chewing on plant leaves.
Therefore, butterflies and bees are generally less affected because they do not feed on treated leaves. However, they can be harmed if directly sprayed or exposed to fresh residues on flowers.
Do not spray on blossoms or flowers that these pollinators might land on. And do not spray helpful insects with it.
Effect on Pets and Animals
Neem oil is safe for cats and dogs when used correctly. Various pet grooming products contain nourishing neem oil.
Also, experts have tested using neem leaf meal in broiler rations instead of antibiotics [5].
However, neem oil can be harmful to fish and other aquatic organisms [6]. Avoid allowing sprays or runoff to enter ponds, streams, or other bodies of water.
Effect on Humans
Studies have shown that neem oil is potentially toxic to children and adults if ingested in large doses [6].
However, for gardening purposes, you can use it throughout the growing season up until the day of harvest. Be sure to wash your produce thoroughly.
Where to Buy Neem Oil to Use on Your Plants
Pure neem oil, sprays, and liquid concentrates are sold online, at gardening stores, and at other retail outlets.
Neem cake is also sold as a soil amendment and plant fertilizer.
Takeaway
As you can see, neem oil benefits the garden in many ways. As a result, it is widely used in organic gardening and agricultural products.
The benefits of using it on plants are vast, especially for the organic gardener.
I use neem oil for diseases on tomatoes , and keeping moths from laying eggs on my cherries
Thanks for this information. Much appreciated.
Is this safe to spray on a fruit tree after the flowers come out?
It will not harm the flowers but it might harm pollinators.