Stress levels
Psychological and physiological stress levels were measured over the four week period before and after they placed plants on their desks.
Participants recorded their pulse, an indicator of stress response, before and after looking after the plants and completed surveys to measure psychological state and anxiety levels.
About 27% of participants experienced a significant decrease in their pulse rate by the end of the plant-tending period, and most participants' anxiety scores decreased too.
The research team also monitored the participants' psychological stress levels using a measurement called the State-Trait Anxiety Inventory.
The STAI measures two types of anxiety – state anxiety, or anxiety about an event, and trait anxiety, or anxiety level as a personal characteristic.
The participants were also asked to take a three-minute rest at their station whenever they felt stressed or fatigued.
Green is good
The team found that the active involvement of workers in caring for office plants and the availability of greenery in the workspace helped lower their stress and fatigue throughout the experiment.
There was also a noticeable decline in the participants' anxiety levels, which the researchers attributed to the calming effect of the plants.
The team thus recommends placing plants within close sight of workstations to help reduce stress levels in the office.
"At present, not so many people fully understand and utilise the benefit of stress recovery brought by plants in the workplace," said lead researcher Masahiro Toyoda.
"To ameliorate such situations, we decided it essential to verify and provide scientific evidence for the stress restorative effect by nearby plants in a real office setting."
Why does it work?
So what makes a desk plant especially helpful? Having plants to look at presents a healthy, restorative distraction from draining office tasks, according to the study authors.
Other research suggests that nature can serve as an antidote to over-stimulation or "attention fatigue," as well as boost cognitive performance.
Positive attachment
As well as the benefits of looking at the plant the researchers found workers developed a "mild attachment" to their plants which intensified the benefits.
In the study, the plants were only a few inches tall and wide, so could suit even a small or shared office desk.
If your workplace does not allow plants a walk in a nearby park or tree lined street can give similar benefits.