Powdery Mildew (PM)

White powdery coating on leaf surfaces that wipes off and re-grows. A foliar fungal disease that thrives at 18-26 C with relative humidity in the 50-70% range and stagnant air - the indoor flower-room sweet spot. Once present, spores embed in the canopy and the room; act fast and improve airflow before reaching for chemistry.

What usually causes it

• RH consistently above 55-60% in flower with weak intra-canopy airflow
• Dense canopy blocking airflow to lower nodes
• Infected clones or a strain with low PM resistance
• Day/night temperature swings causing leaf condensation (dewpoint hits)

Related product categories

• Fungicides & Disease Control
• Climate & Ventilation
• Plant Protection

Terms worth knowing

• VPD (Vapour Pressure Deficit)

Walk the questions if you are not sure this is the match. The notes above are the same ones the tool ends on.