Do most indoor plants go dormant in the winter?

Most indoor plants come from tropical regions that are warm year-round. Unlike temperate zone plants, tropical plants grow actively all year long. Indoors in northern climates the winter months bring shorter hours of daylight. This reduction in light will cause plant growth rates to slow leading some observers to believe they are dormant.

Does misting increase the humidity for plants?

Misting plants once or twice per day increases the humidity by so little that it has no practical value for humidity-loving plants. Misting does help keep plants clean, however.