If you are indoor grower, you probably heard about VPD chart, there are growers out there that that’s their bible.
VPD is short for Vapor Pressure Deficit which shows what the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated.
Once air becomes saturated, water will condense out to form clouds, dew or films of water over leaves. Think of it as a way of finding the sweet spot for your plants through your environmental conditions. Outdoors air that is hot and too wet produces rain and clouds, too wet and cold and it can snow.
Understanding what your plants need for optimum production comes down to knowing what their natural conditions are where they originated.
Some great land race strains from back in the day were named after where they came from. Ever heard of Columbian Gold, Thai Stick, Panama Red or Afghan Kush? Those name reflect where the plants originated and they stuck. So recognizing that most of those strains came from hot and humid places wouldn’t make sense to give them what they’re used to? Your answer should be yes as that is when the magic happens.
Below is a VPD chart you can use: