There is nothing quite like a lush, tropical plant to chase away the winter blues. But wintertime presents some challenging conditions for indoor tropical plants. Low humidity levels, caused by home heating, can quickly desiccate succulent leaves and stems. Because of its lower angle, the winter sun may burn tender foliage. Cooler temperatures cause slower growth and necessitate careful watering. Dry winter conditions are also ideal for insect pests like spider mites and white flies, which often attack weakened indoor plants. Fortunately, tropical plants are generally hardy and can be coaxed through winter with a little attention to their needs.
Spread out the pebbles evenly in a 1-inch layer on the cookie sheet or other shallow, waterproof pan. Place your potted plants on top of the pebbles so that they are not touching each other.
Fill the cookie sheet with enough water to reach almost to the top of the pebbles, but no higher. Make sure the water does not touch the bottoms of the pots. Monitor the water level often, and refill as necessary to raise the humidity level around your plants.
Spray the leaves of your plants daily with a fine mist of warm water from a spray bottle. Do this in the morning when the plants are not in direct sun.
Move plants at least a few feet away from windows to prevent sun scald and damage from drafts when the light begins to change in late fall. Cover south-facing windows with gauzy curtains or light shade cloth to filter the brighter, more direct light of the winter sun. Remove or pull back the curtains, and readjust your plants so they receive filtered sun in late spring.
Wash the foliage of large, leaved tropical plants by gently wiping the upper leaf surface with a soft cotton cloth, moistened with warm water every few weeks through the winter. Clean dust and dirt from smaller leaved tropical plants using a gentle, medium spray nozzle at least once a month.