Neem oil has become one of the key tools in our fight against the constant invasion of pests in our organic garden. We have definitely tried all kinds of organic homemade and DIY- solutions for controlling the numerous pests that love our gardens. The same thing can be said for dealing with mildews and rusts. Let’s just say this hot humid southern climate of ours can be pretty unforgiving. Finding an organic insecticide or fungicide that is naturally derived and can be safely used in the garden is no easy task.
Neem oil is everything we need rolled into one. Using neem oil in the garden has been a lifesaver time and time again. We have battled off everything from powdery mildew to aphids and scale this year alone.
What is neem oil?
Neem oil is produced from the seeds of the neem tree (Azadirachta indica). The oil rich seeds are pressed to extract the oil. Neem seed oil has antibacterial properties in addition to being an effective pesticide and fungicide.
Neem oil contains a chemical compound, azadirachtin, which is the active ingredient that plays into the control of pests. This compound causes many types of insects to lose interest in feeding and stop laying eggs. It is almost completely non-toxic to all birds, fish, and bees. It is one of the safest organic pesticides and fungicides available.
For garden use, neem oil can be purchased as a pre-mixed spray or a concentrate. Neem is also available as a powder that can be mixed with water for application. It is one of the more commonly available organic pesticides.
Using neem oil in the garden
Neem oil is most effective when it is applied regularly as a preventative control. It works particularly well on younger plants. Neem oil can be applied as a foliar spray or a root drench. When used as a root drench, neem oil acts as a systemic. While insects feed on a treated plant, they intake the azadirachtin chemical causing them to reduce or stop feeding and also interrupts their mating. As a foliar spray, neem oil can smother some types of insects on contact while preventing eggs from hatching.
Gypsy moth caterpillars
Controlling bacteria and fungi
Applying neem oil
We typically use a neem oil available in concentrated form. Follow the directions on the packaging to mix properly.
Once you have spotted the first pest, bacteria, or fungi begin to spray every 7-10 days to provide the most effective control. Supplement your organic pesticide by handpicking any adult insects that you spot while treating. Neem oil is best applied in warm dry weather in indirect light or during the evening as the oil can burn foliage in extreme temperatures.
Be sure to shake neem oil spray well to allow the oil to emulsify in the water before spraying. Spray above and below all of the leaves to give it complete coverage.
Storing Neem Oil
Mix the amount of neem oil concentrate that you need and use it within a few days of mixing. The oil has a limited half-life particularly when mixed in water. I try to use up every last bit of it each time I mix it up. Use any excess mix on particularly problematic plants or as additional root drench to provide continued protection.