What is the Ideal Relative Humidity for Cannabis Cultivation?

26 May 2022

Did you know the relative humidity that is best for cannabis plants varies over the course of their lifecycle and the optimal relative humidity also depends on the plant’s heritage?

This article delves into the different conditions required during the different stages of the marijuana growth cycle and the technology that can be used to control the indoor climate – to simultaneously improve grow quality, increase dry weight mass, and stimulates the manufacture of compounds. 

Many medicinal cannabis growers maintain that soil and nutrients are the most important factors in growing cannabis, however it is environmental conditions that really matter.

Light, temperature, air circulation, light reflection and humidity are the main factors for creating a perfect growing environment.

To enable a year-round yield, the grow room must maintain a consistent climate. Temperature and humidity are essential factors during growth cycles.

Damaging Effects of Humidity in Cannabis Cultivation

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Cannabis is susceptible to a variety of humidity-related diseases such as botrytis, downy mildew and Alternaria.   Correct and consistent humidity levels play a pivotal role in reducing plant disease and maximising plant health

  • Treating humidity in the growing and drying spaces with a dehumidifier for cannabis is the most efficient method to eliminate diseases.

DEHUMIDIFIERS AND HYDROPONICS

A number of factors play a role in controlling humidity: room temperature, room size, number of plants, plant species and air circulation. But, ultimately, nearly every indoor grower, no matter how small or large the application, is going to need a dehumidifier or humidifier to achieve indoor air quality.

  • Whether growing in a greenhouse or closed facility, plants constantly transpire water, increasing humidity. If left unchecked relative humidity will quickly increase.
  • The dew point is reached once water vapour saturates the air. Water starts to condense on the cooler surfaces, including the plants and inside the buds. This condensation leads to the development of fungal pathogens, which leads to the spread of disease and bud rot.

WHAT IS THE IDEAL RELATIVE HUMIDITY FOR CANNABIS?

The relative humidity that is best for cannabis plants varies over the course of their lifecycle. RH levels should be changed during different cycles to optimise growth and health.

It is also important to note that the optimal relative humidity depends on the plant’s heritage. If a plant is native to the tropics, then it can handle a higher RH than a plant native to cooler climates.

dIFFERENT STAGE OF MARIJUANA GROWTH AND THE CHANGES TO THE IDEAL RELATIVE HUMIDITY LEVELS

BENEFITS OF A DEHUMIDIFIER FOR CANNABIS GROWING AND DRYING

Dehumidifiers simultaneously improve grow quality, increase dry weight mass, and stimulates the manufacture of compounds.  There are two types of common dehumidifiers that can be applied, depending on a few variables; a desiccant dehumidifier or a refrigerant dehumidifier.

BENEFITS OF A HUMIDIFIER FOR CANNABIS

There are many varieties of humidifiers on the market however only a few are designed with commercial operation in mind

Humidifiers add moisture to the air. Young plants needs upwards of 65-70% humidity for vigorous growth. The extra humidity is needed because root systems have not fully developed yet, so most of their water is absorbed through the leaves.

To find out more about dehumidification technology and custom build drying rooms, please visit the Humiscope website or message me direct