Easy Ways to Increase Humidity
The best-known method of increasing air humidity is spraying houseplants with warm water. Unfortunately, this is not terribly efficient, since the humidity provided dissipates rapidly. To efficiently raise humidity by spraying, repeat the process several times a day.
A room humidifier will do wonders in increasing air humidity. Just make sure to fill it up regularly. Some modern homes have built-in humidifiers that can be adjusted to the desired level.
It is easy to build a plant humidifier of your own. Simply fill a waterproof tray with stones, gravel, or perlite and pour water over them so that the bottom ones rest in water while the upper ones are dry. Set the plants on one of these pebble trays. They will benefit from the added humidity given off as the water evaporates. By keeping the tray constantly half-filled with water, a nicely humid microclimate will be created.
For house plants with moderate humidity needs, grouping them together during the heating season is a simple solution. Each plant gives off humidity through transpiration. Clusters of plants will create very good humidity in the surrounding air.