A lot of plants come into our homes in December, and whether their stay is good or bad depends on you.

Poinsettias, cyclamen, chrysanthemums and of course, the Christmas tree arrive usually in perfect condition. They're a joy for the household. But they also represent an investment of money.

These plants are not hard to keep in very good condition for several weeks. But their chief enemy is heat — the kind that flows out of the furnace vents in every room or from a blazing fireplace.

People think they should keep these plants warm, like a pet or other warm-blooded creature. But these plants arose in varying climates outdoors, not in your warm living room. Heat dries them out and shortens the life and beauty of flowers.

Avoid the heat

The first rule is to place these potted plants and your tree as far from heat sources as possible. While a Christmas tree is not easily movable, potted plants are. If you have an unheated enclosed space such as an entry or sun room, that makes an ideal spot to store the plants for the few days before a party, providing the space stays above freezing. The cool nights will greatly extend the bloom life of the popular chrysanthemum and cyclamen plants. That is why florists and garden centers keep cut flowers and potted plants in very cool, but not freezing conditions. A drop in temperature at night is especially helpful because it puts the plant to rest.

If you have no sunroom or enclosed porch, these pots should go near a cool window, where the temperature will likely be lower than elsewhere in the room.

Water well

The second thing to think about is water. This is oh-so-easy to do right, but easy to forget. Nothing more than plain water is required. But make it lukewarm, especially for potted plants. Letting a Christmas tree dry out encourages needles to start dropping. Letting potted plants wilt causes yellow foliage, drooping stems and short-lived flowers.

But it is winter, and plants will not dry out as rapidly now as those do out in the summer sun. Just check them every other day. It isn't nearly as difficult a job as trying to keep a hanging basket watered in July. If you go away for a few days, ask someone to take care of your plants so that you can enjoy them as long as possible. A wilted plant is a wounded plant that you probably won't want to keep.

A place in the sun

The third thing is sunlight. A Christmas tree doesn't require sunlight because it has no blooms to open. But flowering plants do, and sunlight through a window will bring out those buds nicely. It helps that window sills tend to be cooler spots than the interior of a room.