Understanding Greenhouse’s Vapor Pressure Deficit (VPD)

Vapor Pressure Deficit is a weird metric that could be used to help make a better environment for your plants in a greenhouse. It’s basically the amount of water the air in your greenhouse can hold, it depends on the inside temperature and the humidity.

Think of it as the “thirst” of the air around your plants. When VPD is too high, your plants lose water faster than they can absorb it, leading to stress and stunted growth. When it’s too low, plants can’t transpire properly, which hampers nutrient uptake and can invite fungal problems.