Keeping your houseplants in top form through the winter can be a little tricky. Days are shorter so they receive less light. Temperatures can vary more causing growth issues. Humidity might be lower so they may need moisture more often. Following are a few tips to keep your plants as healthy as possible.

Try to place your plants in the brightest part of the room. Sunlight at least part of the day is best. Make sure curtains or blinds are open as much as possible during daylight hours. Mirrors or other reflecting surfaces behind plants on the opposite side of the room from windows can help increase the light for plants in those settings.

If you lack adequate windows to provide enough natural light, artificial light can be provided. While fluorescent tubes specially designed for growing provide the best light, any kind of light is better than none. Spotlights can not only provide a focal point, but add to the plant's overall health.

Most houseplants thrive best at temperatures between 60 and 70 degrees F. Above 75 degrees is too warm, and below 55 degrees can be too cool for many plants.

The biggest problem beyond the optimum temperatures is too widely fluctuating temperatures. If you have a programmable thermostat and are gone most of the day, don't set the temperature too low for the plants. Like many people on vacation, they are comfortable basking in the light and warmth of the day. They can take cooler temperatures at night when they are less actively growing.

Winter heating, especially forced air, can dry out the air more than most houseplants prefer. There are a couple of tricks you can employ to increase the humidity surrounding your plants.

One is to use the pot-in-a-pot method. Place the pot the plant is growing in into a larger pot. The outer pot could be more decorative. Fill the space between the pots with peat or sphagnum moss. Keep that material moist at all times. An alternative is to use trays with a 1- to 2-inch layer of pebbles in the bottom. Set the potted houseplants on top of the pebbles and keep the pebble tray filled with water almost to the top of the pebble layer.

Because of changes in light, heat and humidity, your watering regimen is probably going to change in winter. During some times of the year, you might be able to get by with watering on a weekly schedule. The best time to water a houseplant is when it needs it. Different plants, pots and seasons are going to affect those needs.

For most plants, it is best to allow them to get almost dry rather than keeping them too wet. Use a moisture meter or a finger to determine the need to water. The top inch of soil should be dry before you water. If you feel moisture below that level, wait another day. If it feels toward the dry side, it's time to water.

You are going to have the most success with your plants if they are in pots with drainage holes. Add water slowly until it starts to come out the bottom of the pot. Tepid water is better than cold water. If the pot doesn't have drainage, you are going to have to experiment to determine the right amount of water to add each time you water.

If you follow a specific fertilizer program during the spring, summer and fall, reduce it some for the winter. The plants should be looking healthy but they are not growing as much in the winter because of the conditions mentioned above.

Last but not least, give your plants a shower occasionally if possible. For plants that are easily moved, once a month or every other month, take them to the sink or tub and spray them gently with tepid water. This cleanses their pores and improves their appearance. For plants too difficult to move, use a soft cloth and tepid water to wash individual leaves.

When you keep your plants in top shape you'll also improve the air quality in your home for you and your plants.