Could high humidity (above 60%) be causing powdery mildew?

RH above 60% for extended periods. Poor airflow. Dense canopy. Fix: Drop humidity: 55-60% veg, 40-50% flower Run oscillating fans at canopy level constantly Defoliate dense inner growth

Could poor airflow be causing powdery mildew?

Stagnant air inside the canopy. Dense inner foliage. Fix: Prune inner leaves Add clip-on fan at canopy level

DiseasesUrgent — act today

Powdery Mildew on Cannabis

Powdery mildew (PM) is a fungal disease that coats leaves in white powder. It spreads fast, weakens the plant, and makes buds unsellable.

What it looks like

●White powdery patches on leaf tops (like flour dusted on)
●Patches spread and merge over days
●Advanced: leaves yellow and die
●Can appear on buds in late flower (bud rot risk)

Quick diagnostic checks

1Remove affected leaves immediately (don't compost)

2Spray with milk solution (1:9 milk:water) — works for early stage

3Drop humidity below 50%

4For established PM in flower, consider early harvest — bud rot is next

Causes ranked by likelihood

1. High humidity (above 60%)

Most common

Signs

●RH above 60% for extended periods
●Poor airflow
●Dense canopy

Fix

✓Drop humidity: 55-60% veg, 40-50% flower
✓Run oscillating fans at canopy level constantly
✓Defoliate dense inner growth

2. Poor airflow

Common

Signs

●Stagnant air inside the canopy
●Dense inner foliage

Fix

✓Prune inner leaves
✓Add clip-on fan at canopy level

⚠️When to worry

Always. Once established, PM is very hard to eradicate. Prevention > cure.

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