What is the life expectancy of a foliage plant taken into the home? That question is often asked. It depends, of course, on the treatment the plant receives. Some plants not only stay alive for years but continue to be attractive. The same plant in a different home with poor treatment might last only a few months.

But the care the plant receives after it goes into the home is not the only factor; equally important is the condition of the plant when purchased. Many plants are sold in poor condition and should have been discarded instead.

It is a mistake to assume you can buy a sick plant and restore it to good health; the odds are overwhelmingly against it. Even if it were given to you instead of being sold as a bargain, it usually is not worth taking home unless, of course, you are found of nursing and would like to see what you can do with it.

The big problem used to be that the plants were grown in full sun and few survived when taken into the dim light of the average home. That has been taken care of to a large degree by acclimatization (adjusting them to a lowlight environment).

About 44 percent of foliage plants sold in the United States come from Florida. The foliage plant growers of Florida are proud of their plants and most now are producing them in shade or acclimatizing them before they leave the state.

Twenty-nine of the growers have formed an organization called Florida Foliage Producers (FFP), the primary aim of which is to "increase identification of high-quality Florida-grown plants, expand the use of Florida foliage in home and commercial interior design and provide information to consumers, retailers and architect designers."

FFP is developing a labeling program; the label on the plant will be distributed nationally and found only on plants of the member growers, "all of whom have demonstrated high standards and good quality control in growing and shipping foliage."

However, growing and shipping are only part of the problem; no doubt, FFP members have a good idea of the big job ahead of them, teaching thousands of retail store personnel how to take care of the plants so they will be in good condition when sold.

On the way to market, the plants may have been on the road five days in a box without light. We don't know how long plants can go without light and not be seriously damaged; some say seven days is the maximum.

The plants may have become chilled. If the temperature goes much below 55 degrees F. the plants may be badly hurt.

The truck's exhaust system may have leaked fumes into the truck. Gas injury is not severe enough usually to be seen immediately but it is possible there could be visible symptoms.

There may have been a buildup of respiration gases in the packing boxes. All plants produce some ethylene; too high a concentration of this gas will harm them.

Surveys indicate a high percentage of foliage plants are sold to the public in supermarkets. The personnel of almost all of these stores are not horticulturists and do not know how to take care of the different plants. "We need simple, easy-to-understand instructions," they say.

When the plants are delivered to the headquarters of the company that will distribute them to its stores, the tops should be removed form the cardboard boxes and the sleeves (paper wrappers) taken off immediately so air can circulate around them. Plants that remain boxed and sleeved will deteriorate rapidly from lack of vital air and light.

When the plants get to the store that will sell them to the public, they should be placed immediately where they will get good light and not be crowded. The best temperatures for them are 60 to 65 at night and 70 to 75 during the day.

The plants should be watered with room-temperature water when needed; much more damage can be done by over-watering than by underwatering. The plants should not be fertilized.

In many cases, light in the retail shop may be lower than desirable, however the plants should not be seriously damaged unless light levels are too low for easy reading.

FFP members say retail personnel will be provided with helpful information on positioning plants in the store environment and proper living conditions under which the plants will thrive and look attractive.

The public also can help. If the plant does not appear to be in good condition, don't buy it. That is certain to persuade the store personnel to learn how to take better care of the plants or stop handling them.