Greenhouse Gardening

Humidity

Humidity is essentially how "wet" the air is. Hot air holds more water vapor than cold air. Most plants do best with a relative humidity (the percentage of the amount of water that the air can hold at a given temperature) of between 45 and 60 percent. High humidity leads to pest and disease problems and causes vapor to condense when warm water-filled air hits a cold surface. Low humidity, on the other hand, can dry out plants. Transpiration from plant leaves contributes greatly to greenhouse humidity. To avoid excessive humidity, water early in the day and only when needed, and make sure you have good greenhouse ventilation. If your humidity is too low, you can raise it by periodically wetting down the floor or misting plants.

 

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