With the low light levels, short days and cold drafts, your houseplants could exhibit symptoms from dropping leaves to dropping dead. Here are a few things you can do to help them out:

CREATE HUMIDITY

Winter means dry air. When every time you touch something metal and an arc jumps from your fingertips you know the air is very dry. Humidifiers can help to raise the level in your whole house and makes a healthier atmosphere for plants and animals. Small room humidifiers can be used if you concentrate your houseplants in one room or area in the winter. Furnace humidifiers will raise the humidity in the whole house and besides helping your plants you will feel warmer. Moist air holds more heat than dry air.

You'll be able to turn the thermostat down and still feel comfortable. It will also cut down on the lightening bolts from the ends of your fingers. For those plants that still need more humidity you can use the saucer and pebble trick. Daily misting of your plants with lukewarm water will also help. Distilled water is probably the best.

KEEP OUT THE COLD

If your plants start to drop leaves suddenly, it could be from the cold. A sudden cold draft from an open door will shock some tropical plants and cause them to drop leaves.
Another indicator to watch for is black tips on the leaves that mean the plant is getting too cold at night. If you have deep enough windowsills move your plants back away from the windows in the winter.  Another option is to move your plants to a table or stand to ge

TURN ON THE LIGHT

With the short days and low winter light levels most houseplants will go dormant and some will just slowly die back. If they are big enough to stand dying back some over the winter they will pick up again when the light levels rise again towards spring. Any extra light you can provide for your plants will help. Fluorescent lights work just fine and they are economical to operate. Coupled with plant bulbs, they provide the light spectrum plants need to keep growing over the winter. Run them 16 hours a day on timers. They also make incandescent plant bulbs to fit an ordinary light fixture, but keep in mind, they give off more heat and need to be further from the plant. Another option for smaller plants is a light garden. Many of the seed companies and plant outlets sell them. It's usually a set of shelves with adjustable 4-foot fluorescent fixtures. They are a great way to keep your plants going during the winter, and it's easy to build your own. If you don't give your plants extra light over the winter remember to feed them less often since they aren't growing as much and won't need the extra food. Winter is also a good time to re-pot root-bound plants while they are dormant so they will be ready to go in the spring when light levels increase. Use a mix of good potting soil and well-rotted compost and a pot 2 inches bigger than the pot the plant is in. With a little extra care your houseplants will survive the winter and be ready to take off in the spring.