'Come quick! The office ficus tree is turning yellow'

Office workers call them everything from ''flower girls'' to ''shrubbery women.'' In fact, the dozens of young women who fan out across Chicago every morning with their giant watering cans, pruners, and feather dusters in tow are plant tenders. They are part of a burgeoning business that has been holding its own in spite of the recession.

As service technicians of Tropical Plant Rentals Inc., the nation's largest plant rental company, based in Prarie View, Ill., their job is to make a daily check of the hundreds of plants under their charge in banks, hotel lobbies, offices, and shopping malls. The plants in the towering Sears Building alone keep eight workers busy five days a week.

With the tending, which ranges from feeding to cleaning (''the dust film on leaves can cut the light by 50 percent,'' insists assistant manager Art Klecha), goes a guarantee to replace any plants on the wane. ''We like to have them last at least a year, but occasionally we lose one,'' notes Richard Manek, Tropical's downtown service manager. It is partly that added security which prods more companies to rent plants and contract out the care, rather than buy and rely on in-house green thumbs.

But, despite the planned detachment, a few office workers have become hopelessly partial to the foliage in their midst, regardless of how seedy its state. One advertising executive was furious when he realized his favorite dracaena marginatam (Tropical workers use botanical terms, abbreviating only occasionally as in ''Benny'' for a ficus benjamin tree) had been replaced without his knowledge and demanded its return. Plant caretakers scurried to the company's downtown warehouse where both replacement and used plants are stocked. They managed to retrieve it, and the executive is happy once again.

Tropical's technicians, who often have plants of their own at home and are frequently asked for advice, are sometimes as partial to their assigned plants as those who work next to the greenery. Katie Arnold, who tends 1,200 plants at the IBM Building here, recalls the day recently when she noticed a ''Benny'' missing from its usual spot on the 39th floor. When employees conceded it had been moved down to the 25th floor and wondered how she could possibly notice such a detail, she told them exactly how it was.

''All these plants are like my children - they're my babies - I know exactly which ones are on which floor,'' she explained. The tree stayed on the 25th. ''It was I who had to make the adjustment,'' she said.

As the plant tenders tell it, many office workers worry about the plants despite the daily care given by the outside service. Many telephone in a report whenever a plant is not looking its best.

''A lot of people panic when they see one yellow leaf,'' notes Shena Hillard, an assistant superviser for the company and a recent horticulture graduate from Purdue University. The cause of the yellowing, she says, could be anything from too much to too little water or being too close to a heater.

''You get a lot of people trying to help you, like giving the plant extra water - there's a lot of public-relations work in this business,'' Mr. Marek says.

Plant varieties are assigned according to the light and scale of their surroundings. If light is strictly limited, as in many downtown Chicago buildings, a plant from the dracaenam family or sansevieriam may be recommended. Marek says most green plants need more water in the winter when heat is on than in the summer but that the biggest adjustment - sometimes marked by leaf shedding - comes not with the change of seasons but with the shift from nursery nurturing to office life. Many of the plants are grown in the company's south Florida nurseries and are shipped north in temperature-controlled trucks.

''What I like about this job is the fact that you're constantly learning new things - you never get bored - and the exercise is terrific,'' says Susan Kramarik who tends a North Chicago route that includes several apartments. In one of her accounts - an apartment atrium now full of poinsettias - toads (and maybe lizards as well) are to be added as insect control. ''I'm really looking forward to that,'' she says.