Anyone who has some experience with growing plants in a greenhouse knows how important it is to maintain consistent humidity levels. Often gardeners have to deal with low humidity and high temperatures. If the humidity is not controlled properly, plants can become damaged and even die. If the humidity drops below 30%, the plants can stop growing. A greenhouse misting system produces a high-pressure fog or mist that evaporates instantly to cool and humidify, without causing too much moisture to accumulate.