For more information, visit: br Marijuana flourishes through a wide range of relative humidity. It can grow in an atmosphere as dry as a desert or as moist as a jungle. Under ordinary household conditions, the humidity will rarely be too extreme for healthy growth. The effects of humidity on plant growth are closely tied to temperature, wind speed, and the moisture of the soil. br br The theory of transpiration is a process similar to evaporation. It inherently involves the rate at which your plant expels and, subsequently, absorbs moisture. Transpiration also cools plants and enables flow of mineral nutrients and water from roots to shoots. It is closely connected with the plants’ stomata, which are like pores on the leaves of a marijuana plant that open and close to accommodate the external and internal availability of moisture. The goal of the stomata is to protect the marijuana plants from dramatic changes in moisture.