Those of us who enjoy plants look on this time of the year in a couple of ways. First, we're frustrated because we have been deprived of all those outdoor plants that have furnished us with a display of color. Second, unless we have a special greenhouse or other highly lighted area, indoor plants are more of a problem to keep growing well and looking good.

Many of you have breathed a sigh of relief because the marigolds and geraniums are blackened. The long 1988 growing season is over! Other plant lovers will accept the challenge of maintaining close relationships with the plant world even though multitudes of problems must be faced and overcome.An Ohio State University newsletter brings to our attention desirable effects from having plants in our surroundings:

"NASA scientist Dr. B.C. Wolverton is conducting some exciting new research at the John C. Stennis Space Center in Mississippi. He is examining the idea that plants can purify the air in a spacecraft and keep it clean. His current studies show that plants do a "superior" job of removing benzene from the air.

Plants are also quite effective at eliminating carbon monoxide and cleaning up formaldehyde. The implications for the plant industry go far beyond space shuttles. Benzene, carbon monoxide and formaldehyde are common air pollutants in modern buildings. Today's tight, energy efficient structures have far fewer air leads to disperse these pollutants. People can get headaches, nausea and other ills from these pollutants. Plants may provide a solution.

As we visit the garden centers and plant shops we can be overwhelmed with the array of choices available to help us clean our polluted surroundings. Of course, there is one that predominates the displays this time of the year. That's the traditional poinsettia, a marvel of color to brighten drab surroundings.

That tropical plant has been much improved to provide more sturdy, persistent colorful bracts to last beyond the Christmas holiday season. Yes, what most people call the flowers are really modified leaves. Poinsettias have been developed in red, pink, white and marbled colors. With proper care, they will maintain their decorative value well into February.

That proper care begins with the selection process. Choose a plant with the least pollen showing on the small greenish buttonlike flowers. Open yellow flowers mean a more mature plant.

Because the poinsettia originated in southern Mexico, it resents the outdoor climate of northern Utah. Don't stop to shop and let the car get below 60 degrees. During the day, 65-70 degree temperatures will prolong their life. At night, 60 degrees is about the lowest it should get. Poinsettias like a bright location, but if they're too close to a window on a cold night, leaves may be damaged. Move them from drafts such as an opening outside door or a heat vent.

Keep the soil uniformly moist, but daily irrigations probably won't be needed. Wait until the soil surface is somewhat dry. Once a week, fertilize with a half-strength soluble house plant fertilizer such as Rapid-gro or Miracle-gro. A January "In Your Garden" will explain post-holiday poinsettia care.

You still hear and read references as to the toxicity of poinsettia leaves. Recent tests have proven that they are of little hazard around the home. Poinsettias contain a milky sap, as do most plants in the Euphorbia genus. This sap can irritate skin and cause pain in contact with open cuts or eyes, according to the Sunset Western Garden Book.

You can choose other colorful plants that greenhouse operators have coaxed into bloom this time of the year for you or for a gift. Azaleas, chrysanthemums, kalanchoes, gloxinias and begonias all come in assorted colors and with good care will give weeks of enjoyment. Adequate light, enough but not excessive water and room temperature on the cool (70 degrees) side are conditions to prolong flowers' lives.

It's very difficult to provide an environment in the average home to coax these plants into repeat bloom cycles. Consider them to be a long lasting bouquet. Don't become so attached to them that they can't be discarded after they've lived their useful life.

A couple of plants, related to one another, may provide color but not with their blossoms. These are the fruit-bearing pepper and Jerusalem cherry. If small children are around and there's a chance that they will consider colorful "berries" an edible delicacy, these plants are probably not for you. The Jerusalem cherry fruits resemble a cherry tomato but are poisonous if eaten.

The peppers are colorful in an array of green, yellow and red. Those pods are edible but very hot. If they contact eyes or other tender tissues of children, there would be a great deal of lasting discomfort.

Those of us without a highly developed green thumb can choose from many assorted foliage plants. Although their color display is not as intense as some just mentioned, variegated leaves or stems will brighten our homes. Some of this category are good air purifiers because their leaf surface is so extensive.

Foliage plants aren't as fussy about light, water and temperature factors and will survive some "benign neglect." Garden centers or the books they carry will provide specific care instructions for your new purchase.

Here are some choices to consider: Devil's ivy (Pothos), Spider plant, Maranta (Prayer plant), Syngonium (Arrowhead plant), Peperomia, Sansevieria (Snake plant), Dieffenbachia (Mother-in-law plant), several Philodendrons, Cracenas and Schefflera.