The warm, dry house that is your sanctuary during the cold months is decidedly less inviting to the plants brought there at summer's end. Dry air can leave plants susceptible to insect infestation and other problems. To protect them, take these steps to make their environment more humid: Layer the bottom of a watertight, rustproof metal tray (available at baking- or garden-supply stores) with pebbles. Set the tray where plants will receive adequate light, then fill it with water almost as high as the tops of the pebbles. Place the pots on top of the pebbles, making sure to keep them out of the water. The continuous evaporation of water will create the humid conditions in which most plants thrive. Replace the tray water as necessary, and water plants as usual (the runoff will collect in the tray). Mist pebble surfaces -- and plants, too, if appropriate.
Healthy Plant Tray
Martha Stewart Living, September 1998