Neem Oil on Cannabis: How to Use It and When Not To
By The Budometry TeamPublished Updated
Neem oil is effective, cheap, and widely available, which is why it is overused. It has a specific window where it belongs and a hard line where it does not.
Part of our pillar guide: Plant Training, Pests and Troubleshooting
How to mix and apply
Roughly 1-2 teaspoons per quart of warm water with a few drops of mild soap as an emulsifier, mixed fresh each time. Apply with lights off or right at lights-out, because oil plus intense light burns leaves.
Coat leaf undersides thoroughly. Repeat every 5-7 days for three applications.
Never in flower
Neem leaves a residue and a distinct smell that carries into dried flower. Stop all neem applications before the flip, or at the very latest in the first week of 12/12.
Alternatives
Insecticidal soap rinses cleaner. Predatory insects work during flower. Environmental control prevents most of what neem treats.
Frequently asked questions
- Can I use neem as a soil drench?
- Yes, it is used against soil-dwelling larvae, but the same flower-stage residue caution applies.
The full guide on this topic
Plant Training, Pests and Troubleshooting
Topping, LST and SCROG explained, plus how to identify and stop spider mites, fungus gnats and powdery mildew, and how to read leaf symptoms correctly.