Deck the halls with holiday houseplants

If you want to cheer up your home at this time of year, add a holiday houseplant. Its warmth and richness also make it an excellent gift. Here's a primer on how to care for some of the most popular gift plants:

* Poinsettia.

This has been the most popular Christmas plant for many years. Before you buy this year, look for the new hybrids, which are shorter and fuller and contain more of the colored bracts than the skinny, lanky plants.

Besides the traditional reds, you can now find lovely pinks and white, and some that are attractively mottled.

The new squatty varieties will often hold their color beyond Easter if you (1 ) keep them evenly moist at all times; (2) provide coolish temperatures; (3) avoid drafts and bursts of hot, dry air; and (4) provide bright light and high humidity.

* Azalea.

An azalea in full bloom is hard to surpass. To prosper, however, it wants a very cool location (no higher than 60 degrees F., if possible, with some sun). An azalea should never dry out.

Miracid added to the water three or four times a year is desirable, as azaleas are definite acid-lovers.

Because it is not as sensitive to cold as most houseplants, you can let it enjoy a rain shower now and then.

* Cyclamen.

For best results, cool temperatures are required. In fact, they do very well with temperatures in the 50s.

A pebble tray larger around than the size of the plant can provide the high humidity they demand. We keep water just under the pebble surface all the time. When they're producing their flowers, they should never be dry.

Later, when the leaves begin to yellow, watering should be reduced so they can take a rest.

A big florist cyclamen is not the easiest houseplant to maintain. However, the newer miniatures, which come in pink, salmon, white, and bright red, have far less difficulty with an outside environment.

* Christmas cactus

Like the poinsettia, the hybridizers are doing great things with all the holiday cactuses. Besides the cherry reds and corals, there now are lavender, tangerine, white (it has a faint blush of pink), salmon, and shocking pink.

Holiday cactuses, which come from the moist jungles of South America, have nothing in common with the spiny desert dwellers. Thus, they like even moisture, cool nights, and rich soil.

After the blooms pass, do a little pruning if your plant is at all sizable. Remove any branch that crisscrosses.

Holiday cactuses can make a very desirable hanging plant.

Because of their longevity, if properly cared for some holiday cactuses have passed down through families for more than a hundred years.

* Potential.

This is the password when choosing all plants. Buds, rather than full blooms, will give you the pleasure of their unfolding, and you will have flowers over a much longer period of time.

Properly cared for, a young plant will delight you with its performance. A tired, more mature plant, on the other hand, won't bring much pleasure.

Look for young, healthy specimens when you buy a houseplant.