By now, you’ve no doubt heard of the miracle product known as neem oil. This all-natural tree extract shows up in beauty products, healthcare, and a wide range of agricultural applications.
Yet you’re probably a bit confused by the mixed messages out there on how useful neem oil is for plants.
Neem affects insects differently than chemical solutions. While it can take up to two weeks to see results, it’s far more successful at eliminating infestations in the long term.
Another controversy is whether neem is safe for agricultural use.
While lauded in most of the world, neem oil is currently banned in Canada due to the potential side effects of misuse.
Knowing how often to apply neem oil protects plants from potential damage. It will also help protect beneficial insects from coming into contact with this natural insecticide.
Check out this article on What Bugs Neem Oil Kills.
How Often Can You Use Neem Oil On Plants?
As a general rule, neem oil is just for eliminating infestations.
Yet, you can use it as a preventative every 2 to 3 weeks.
How Often To Use Neem Foliar Sprays
Neem foliar sprays use a processed form of organic neem oil insecticide known as clarified hydrophobic neem oil.
This oil has most of the active ingredients of Azadirachtin removed, resulting in concentrations of .5% to 3% percent.
As a topical solution, neem foliar sprays suffocate insects on contact and kill some external fungal diseases and infections.
But, it requires application every other day for at least 14 days for it to work.
Apply at either dusk or dawn to prevent contact with beneficial insects such as ladybugs or honeybees.
Once you end any current infestation, you can safely use the foliar spray once every two weeks for prevention.
How Often To Use Neem Soil Soaks
Soil soaks or a Neem drench are a very different story.
The soaks use 100% percent cold-pressed pure (AKA raw) neem oil.
Pour this version of neem oil for plants on the soil so the plant’s roots can soak it up, turning it into a systemic insecticide.
The Azadirachtin will remain potent within the plant for up to 22 days. It will only affect piercing or chewing bugs.
It makes it far safer for use on plants near beehives.
Due to the longevity of the Azadirachtin, repeat soil soaks every 21 days to keep the potency.
Azadirachtin kills most infestations without harming pollinators and beneficial critters such as earthworms or predator species. But it will also help combat many bacterial and fungal infections, including some forms of root rot.
When NOT To Use Neem Oil
Something not discussed enough is when you shouldn’t use neem oil on a plant.
While non-toxic and often used in products such as toothpaste, it’s generally agreed that you should not apply neem to an edible plant the day of harvest.
You can use a foliar spray the day before, or soil soaks before harvest. You will ingest less if you avoid applying it on the actual day of harvest.
Another essential rule is constantly testing a small part of a plant one day before using neem oil products.
Plants, like people, can have or develop allergies and sensitivity to even natural products.
By testing a small portion of the plant first, you can check for signs of chemical burns or allergic reactions.
When using neem regularly, you may only need to test once. Yet you should always retest the plant if you haven’t used neem oil on it for an extended period.
If you see an adverse reaction from testing or regular use, you should stop using neem products on that plant immediately.