Neem Oil and Cannabis
Neem oil is a great tool for any organic cannabis gardener. I like it because it is safe, cheap and easy to find. You can buy it online or at Home Depot, Dixieline, Walmart or at any Hydro Store. Neem oil is available in concentrate, where you have to measure it out or can purchased as ready to use. The concentrate form is usually cheaper, but you need your own sprayer. Hopefully the following text will clear up any questions you have about how to use neem oil on cannabis plants.
What are some good brands for Neem Oil?
Concentrate: Dyna Grow Neem Oil or Bonide Neem Oil
Ready to Use: Monterey Neem Oil
What is Neem Oil?
Neem oil is my go to for bug and mildew defense. It is by far my favorite organic pesticide for a number of reasons. First, it is really easy to apply and safe around my family. Neem oil is biodegradable, nontoxic, and organic. It’s safe around fish, birds, pets, livestock and wildlife. It comes from an evergreen neem tree found in India. The oil is created by crushing tree seeds and adding water.
How to use Neem Oil on Cannabis Plants
Neem Oil only targets leaf sucking and chewing insects. It works great against all types of bugs including aphids, mites, scale bugs, white flies, caterpillars, mealybugs and thrips. When applying neem oil to cannabis, make sure to spray on both sides of the leaves. A good sprayer definitely makes this job easier.
When used as a soil drench, neem oil is effective at controlling unwanted nematodes by preventing their larvae from hatching. Fortunately, beneficials like earthworms are not affected by neem oil. 🙂
Lastly, neem oil can prevent or kill fungus. Use neem oil to treat powdery mildew, black spot, rust or leaf spot.
When is the best time to apply Neem Oil?
I always spray neem oil late in the day. Some studies have suggested that neem oil affects bee’s. So to protect our precious bee’s please spray late in the day!
Can I use Neem Oil indoors?
Yes. Neem oil is safe for indoor use. It is nontoxic and biodegradable.
How Long will Neem Oil Last?
Neem oil degrades quickly in sun light and during rainfall. When mixed with water, it can be stored up to 4 days. Shake well before using again.
Conclusion
Lastly, if you have any questions please post them in the comment section. If you are interested in learning even more about growing cannabis, please check out my blog. Here are a few of my most recent posts:
- The Cannabis Growing Season – Southern California
- Is a Grow Tent Necessary
- Trichomes When to Harvest
- Cannabis Water Filter
- Organic Fertilizers for Cannabis
- Cannabis Pot Size Guide
21 Comments on “How to use Neem Oil on Cannabis Plants”
Should Neem oil be washed from buds before drying?
Should Neem oil be rinsed from buds before drying?
If you sprayed within the last day or two washing wouldn’t be a bad idea, but Neem oil degrades very quickly. As a rule, I always try and avoid spraying when I plan on harvesting within 2 weeks.
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How often during a grow does one spray a plant w need oil?
Scott,
If you are experiencing issues like pests or powdery mildew then spray every few days until conditions improve. I would also double check the instructions on your neem oil for spraying directions. Hope that helps!
Do you spray only at night? And must it be rinsed from leaves by morning?
Dawn,
I definitely prefer spraying late in the afternoon after the Bee’s have stopped flying. I think it’s the best time to spray. As for your second question… neem oil degrades quickly in sun light. It doesn’t last long. The amount of time it takes to degrade depends on the weather conditions (4 days to a week or two).
Can you use neem oil during flowering
Hi Brian,
This is a tricky question to answer without more information about your situation. As a general rule, I always try to avoid spraying close to harvest.
However, Neem oil does degrades quickly so it is an option if needed.
Great post.
How long before dark should I spray neem oil on my cannibus plants.
I like to spray around 2 hours before darkness.
Informative.
You said Neem oil degrades in sunlight. I have plants in fabric bags in a grow tent that had fungus knats, so I sprayed Neem oil on them last night. Question is, is my 600 watt grow light breaking down the oil faster than normal?
TY,
Debra
Hi Debra,
I don’t think your 600w light is breaking down the oil any faster than normal. On a side note, getting rid of Fungus gnats can be challenging. You might want to consider spraying your soil with a water/hydrogen peroxide mix. Use 4 parts water and 1 part hydrogen peroxide for your mix. Spray a few times over a week or two and this will kill off the larvae.
Good Luck!
I have leave septoria I sprayed neem oil on them in the evening and took infected leaves off. Now it is raining, so how often do I spray the neem oil on them?
Kathy,
Rain can sometimes wash neem oil off. If you feel like you need to spray again, I would do so soon.
I have the Bonide brand Neem oil spray. It says it’s %0.9. Do I need to dilute it?
Very helpful article . Thank you