悟る · diagnose & fix
Cannabis Powdery Mildew
Disease / mold · also: white powder on leaves, PM, white mold cannabis
White powdery patches on leaves and stems — a fast-spreading fungal infection driven by humidity and poor airflow.
Not sure it's powdery mildew?
Snap a photo and get a free read — no signup. Satoru weighs the visual against the conditions that cause look-alikes, so you treat the real problem.
What it looks like
Flour-like WHITE powdery spots on leaf tops (and stems), starting as small circles that merge into a dusty coating. Wipes off but returns. Thrives in high humidity with stagnant air.
Symptoms
- White powdery/dusty patches on leaves and stems
- Spots spreading and merging over days
- Leaves yellowing/curling under heavy infection
- Musty smell in severe cases
Causes
- High humidity (especially in flower)
- Poor airflow and overcrowded canopy
- Big day/night temperature swings causing condensation
How to fix it
- 1Isolate and improve airflow immediately
- 2Lower humidity into the stage's target range
- 3Remove the worst-affected leaves; treat with a PM-appropriate product (never on buds near harvest)
- 4Defoliate to open up the canopy
Prevention
- Hold humidity in range, especially in flower
- Strong airflow; don't overcrowd
- Quarantine new plants
悟る · how satoru tells it apart
PM is a humidity-and-airflow problem as much as a fungus one. Satoru pairs the photo with your logged humidity so the fix addresses the room, not just the visible spots.
Commonly confused with: Bud Rot (Botrytis).
Not sure it's powdery mildew?
Snap a photo and get a free read — no signup. Satoru weighs the visual against the conditions that cause look-alikes, so you treat the real problem.
More plant problems
Educational reference for cultivation troubleshooting. Symptoms overlap — when in doubt, match against your own conditions. Satoru fuses your photo with your logged environment for a grounded read.