Optimal Humidity for Indoor Plants

Every crop has its own optimal humidity level, which may change depending on the stage of growth. On average, a good target for plant growth is about 50 percent humidity. Plants growing in low humidity will dry out faster. When the air around a plant is dry, it creates a high vapor pressure deficit (VPD).

Plants that dry out because of low humidity in the air become more susceptible to disease. Pests like spider mites love dry conditions and will attack plants that are already stressed from a lack of moisture.

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