With proper care, your holiday poinsettia plant can bring pleasure for weeks or even months after the holiday season ends, according to Dave Robson, University of Illinois Extension horticulture educator. House temperatures, as well as light and humidity levels, affect the length of time the plant will remain attractive.

First brought to this country from Mexico in 1825, the poinsettia has long been the traditional Christmas pot plant. Red-flowered forms are the most popular, but white, pink, and variegated pink and white varieties are also grown.

Most of the newer poinsettia varieties retain their leaves and bracts remarkably well and may stay in good shape for several months. Yet, poinsettias are sensitive to drafts, too cool or too warm temperatures, sudden temperature changes, dry atmosphere, improper watering, and light.

These adverse conditions can cause loss of leaves and withering of bracts--the showy, colored structures commonly called "flowers." The true flowers are actually the yellow nubby parts tucked down in the center of each whorl of bracts.

Robson recommends keeping a uniform room temperature for poinsettias between 60 and 68 degrees F during the day and 10 degrees cooler at night. Humidity levels of 20 to 50 percent are ideal, though these may be difficult to achieve in the winter with the furnace drying out the air.

Robson also recommends grouping the plants together or placing them on water-filled trays of pebbles to increase humidity levels. Temperatures above 75 degrees F are detrimental, particularly in a dry atmosphere.

The plant should be placed near a bright window, just out of direct sunlight, or be provided with 14 hours of artificial light. If windows aren't airtight and leak cold air, move the plants farther back.

"It has been said that more plants are killed or damaged by 'drowning' than anything else," said Robson. "Plants need air as well as water, so avoid over-watering."

Learn to gauge the moisture content of the soil by its color and feel. As the surface dries, it gets light-colored. Pots also feel lighter. When soil is too dry, it becomes firm and sometimes cracked; when saturated, it feels slimy and sticky. Experience helps in finding the ideal condition.

Robson said soil moisture should be maintained at moderate and uniform levels, neither soggy-wet nor bone-dry.

"Never let the pot stand in water for any extended period of time," he said. "If the plant came wrapped in foil or other watertight material, be sure to punch holes in the bottom or remove the wrap entirely so water won't be trapped inside."

Poinsettia plants can be cut back by half in mid-March to encourage new shoots. Poinsettias can be placed outside in the spring after danger of frost has passed and brought indoors in mid-September to early October to force into bloom.

On the other hand, there is nothing wrong with relegating the poinsettia to the compost pile once you've enjoyed it to its fullest and all the leaves have fallen.