Most of the indoor plants originate from humid jungle environments - air moisture is critical for them. In general, such plants tolerate 40-60% humidity level (it is much higher than most of our homes maintain). In winter, the humidity level must be increased even more for your houseplants to thrive.
We recommend placing several plants in a group, thus creating a ‘pocket of humidity’. You can also put a dish of water in the center to create a humid microclimate. Another option is to use pebble trays - play a layer in the tray and water until the pebbles are not quite covered; then, set the plants on top. This will help to hold the plant above the water and keep the roots not constantly wet. Water evaporation increases the air around the plant.
Be careful: too high humidity levels can cause mold growth or damage your home furniture. If you notice your houseplant leaves turning red or brown, it is a signal of the excessive humidity level.
You can also buy a humidifier that will help you to create the ideal climate in your home. Check for Honeywell, TaoTronics Cool, Vicks Warm, Pure Guardian models.