Indoor Cannabis Humidity Control

Cannabis growers control all climate parameters, including humidity, and there are several reasons to do so.

Ideal Humidity Range for Cannabis

Cannabis has an ideal humidity range, just as it has an optimal temperature range. Most cannabis growers prefer a range of 40-70% relative humidity, depending on the growth stage.

In terms of VPD (vapor pressure deficit), the ideal range is 0.8-1.1 kPa during the growth stage, and 1.0-1.5 kPa during flowering stages.

Preventing Molds and Mildews

While the ideal humidity range has a huge impact on development, it’s not the only reason to control humidity. Perhaps the biggest issue with humidity is mold. The most common of which being bud rot (also known as gray mold or botrytis) and powdery mildew.