If employers want to increase job satisfaction, a little shrubbery apparently goes a long way. Workers are happier when offices have plants and windows, a new study found.

American office workers spend an average of 52 hours a week at their desks, according to the 2000 U.S. Census.

Some might argue that not all that time is spent working, but still, all those hours in windowless offices with artificial light can take their toll.

A few green additions could have a large effect on worker happiness, according to the study led by Tina Cade, an associate professor of horticulture at Texas State University, and Andrea Dravigne of the San Marcos Nature Center.

"We pretty much found out that if you had windows and plants, or even if you just had plants in your office, you were more satisfied with your job," Cade told LiveScience. "We thought it was important for offices because a lot of times people are looking for ways to keep employees happy and do all these expensive things like put in a daycare or a workout room. Maybe for less investment they could put in a few plants in strategic places."

• Click here to visit FOXNews.com's Natural Science Center.

The team surveyed 450 office workers in Texas and the Midwest, asking questions about job satisfaction and work environments. They found that people who toiled in offices with plants and window views reported they felt better about their job and the work they performed compared to those in windowless offices without shrubbery around.

When asked about their overall life quality, 82 percent of people who work with plants and windows around said they felt "content" or "very happy."

Only 69 percent of those who work with plants but without windows, and 60 percent of those who have windows but no plants, said they felt this way.

The group of people who work without plants or windows were the most dissatisfied, with only 58 percent of them saying that overall they were "content" or "very happy." While no one who works with plants, windows, or both reported they felt "miserable," 0.8 percent of those who work in offices devoid of either said they were "miserable."

"I was really surprised that having a plant in your office appeared to be more beneficial than having a window in your office," Cade said. "Everybody says, 'I need a window!' but actually it seemed like a plant could be a suitable alternative."

The researchers said they controlled against the influence of salary, position, age, and ethnicity, so they don't think those factors can account for their results. The differences they found in job satisfaction and overall quality of life were statistically significant, they said.

Somewhat surprisingly, the surveys showed men to be more affected than women by the presence or lack of plants and windows.

"People will say that women react more to flowers and green stuff, but we actually saw the biggest differences in the guys," Cade said.

The scientists hope their research may influence employers, architects and urban planners to remember to keep flora around.

"Based on what we've found, it needs to be considered in planning," Cade said. "A lot of times these things are seen as luxury items, but this speaks to the importance of trying to keep spaces green, both inside and outside."

The researchers detailed their findings in the February 2008 issue of the journal HortScience.

Copyright © 2008 Imaginova Corp. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.