Firms branch out to bring petal power to corporate America.

New York's concrete jungle keeps getting greener.

As environmentally-conscious building is becoming more main stream, plants that once graced only the terraces of towers are starting to be incorporated into the floor plans of office interiors.

Landscape designers believe that the benefits their products bring to employers, including absorbing toxins in buildings with stale air, providing humidity during dry winter months, and helping to reduce stress and aiding in employee retention, will sustain the longevity of their businesses.

"At the time when we started our business in the late 1970's, putting plants in buildings was a fad and most building owners didn't believe we would be around long enough," said Howard Keith Freilich, owner of Blondie's Treehouse Inc, a landscape design firm that caters to businesses across the tri state area, including Fortune 500 companies.

"I started the business by myself selling plants on a street corner. Now I have 160 full time employees and our company sales are in excess of eight figures. I think much of our success came about because, over the years, people came to understand the benefits of this kind of design. Owners know that this isn't a fad, that their plants will be maintained, that we are here to stay."

Christopher Raimonidi, principal of Raimonidi Horticultural Group, believes people's interest in shifting towards environmentalism has really become apparent in the past 18 months to two years.

"There is a marked difference in people's attitudes towards our work,' Raimonidi said. "Besides being busier than ever, the questions that clients are asking us are specific to information that is present from the green building movement like, 'Will this plant clean the air, will those plants help us get LEED credits,' things like that."

That specificity began trickling down to interiors upon the emergence of sick building syndrome research that revealed the poor air quality in many of Manhattan's buildings was impacting workers performance. It was solidified when new research revealed the very real benefits of plants.

"Since NASA published that research about how plants act as clean air purifiers, removing toxic byproducts like benzene and formaldehyde from the air, people's interest has been piqued," Freilich said.

Projects like Natures Design and Plants for Work have been created nationwide to help verse architects and landscape professionals on the benefits of plants, to give them certification and to inspire them to create cutting edge products. Raimonidi's firm is always trying new designs. It won awards for its work greening an atrium in a three story United Parcel Service building in Manhattan. The ventilation system of the building pulls air across the atrium, grazing the ficus fig fiddle leaf and palm plants, then redistributes it to the top floors, thus re-oxygenating the air while cleaning it. The firm is currently working on a project designing vertical walls created from soils and plants that will act as a natural filter for the air of a building in lieu of fans or other traditional ventilations systems, trapping bad air in the wall for the plants to absorb and process.

"If the project works, it could provide a revolutionary way of filtering air," Raimonidi said.

The green movement has given firms a lot more material to work with.

The project that allowed Ellen Zachos, owner of Acme Plant Stuff, to cart a tractor trailer load of 30 foot tall bamboo into a corporate office building in Manhattan may not have been possible before green building had become so popularized, she said.

The real benefits of plants in the work place, cannot necessarily be measured scientifically.

"There is a lot of emotion connected to plants. Employers integrating plants into their offices are beginning to realize that the way employees connect to plants emotionally, destresses them and contributes to creativity and productivity and, ultimately, makes good business sense," Raimonidi said.

"I have never really had a client saying 'I am breathing better now that the plants are in place,' but I get positive feedback all the time that the design of a building may have been good but that until we put the plants in the client never really felt settled, never really felt like they were home," said Zachos.

"I feel very fortunate to be able to do something that is creative and that I love that brings smiles to clients faces.

"Before we do the work, we can bring them a rendering or a picture to show them what the project might look like when we are done. But after the work is complete, you can just go and sit there in a lobby maybe, and see how people smile, and how their attitudes change when they look at an installation.

"That's very gratifying and it keeps me going."