Dr. Roger S. Ulrich of Texas A&M University, Helen Russell of Surrey University, England, and Dr. Virginia Lohr of Washington State University found that common interior plants made participants 12% more productive and less stressed than those who worked in an environment with no plants.



The Wall Street Journal reported in August 2003 that “simply observing a lush landscape holds a powerful ability to promote measurable improvements in mental and even physical health.”

The Associated Landscape Contractors of America reported that placement of plant materials can lower heating and cooling costs by as much as 20%.

Researchers William J. Fisk and Arthur H. Rosenfeld of the Lawrence Berkeley National Laboratory, Berkeley, CA, found that the presence of plants could save $58 billion per year by preventing sick building syndrome, and save another $200 billion in improved worker performance.

The Environmental Research Laboratory of John C. Stennis Space Center (NASA) discovered that plants act as a natural air purifier, and may be an effective remedy for sick building syndrome.

Fisk and Rosenfeld of the Lawrence Berkeley National Laboratory found that 40% of all sick days are related to poor indoor air quality.