It is absolutely safe to spray neem oil on soil, especially when used as a soil drench. Neem oil is derived from the seeds of the neem tree (Azadirachta indica) and has been used for centuries as a natural insecticide and repellent. It is known for its effectiveness in controlling a wide range of pests, including aphids, mealybugs, whiteflies, and spider mites.
When neem oil is sprayed onto the soil, it is absorbed by the plant’s root system and transported throughout the entire vascular structure of the plant. This means that the active ingredients, such as Azadirachtin, are distributed to all parts of the plant, including the leaves, stems, and fruits. As a result, pests that feed on these plant parts are also affected by the neem oil, helping to control their populations.
One of the great advantages of using neem oil as a soil drench is that it does not harm beneficial insects. Beneficial insects, such as ladybugs, lacewings, and parasitic wasps, play a crucial role in natural pest control by preying on harmful insects. Unlike synthetic insecticides, neem oil specifically targets pests while leaving beneficial insects unharmed.
I have personally used neem oil as a soil drench in my garden, particularly on fruit trees, and have found it to be highly effective in controlling pests. I have noticed a significant reduction in aphid populations on my apple trees and have also observed fewer instances of mealybugs on my citrus trees.
It is important to note that neem oil should be used according to the instructions provided by the manufacturer. It is typically diluted with water before application, and the recommended dosage varies depending on the severity of the pest infestation. It is also advisable to apply neem oil in the early morning or late evening when beneficial insects are less active.
In addition to its insecticidal properties, neem oil also has other benefits for plants. It acts as a fungicide, helping to control fungal diseases such as powdery mildew and black spot. It also has some anti-bacterial properties, which can be beneficial in preventing bacterial infections in plants.
To summarize, spraying neem oil on soil, especially as a soil drench, is a safe and effective method for controlling pests. It is absorbed by the plant and distributed throughout its vascular system, providing broad-spectrum insecticidal protection. Neem oil does not harm beneficial insects and can also help control fungal and bacterial diseases.