During the winter, most homes have less than 30 percent humidity and some houseplants may suffer. Humidity can be increased with a humidifier. Setting plants on pebbles in a water-filled tray increase humidity too. Make sure the pots are not sitting directly in water. Another technique is to group plants together which improves the humidity immediately surrounding them.
Misting plants does not always work well. The humidity level is affected for only a short time and repeated misting is necessary. While some plants tolerate misting, other plants do not. With too much misting, the incidence of disease may increase.