Benefits of Indoor Plants

The benefits of gardening are not limited to the beauty and productivity of an outdoor garden. Indoor garden plants have long been known to have positive effects on the mental and physical health of office workers. Specifically, a 1998 study by researchers in Norway revealed that workers in offices complained less about fatigue (reduced by 30%) and cough (reduced by 37%), and reported lower levels of throat and skin discomfort (reduced by 23%) relative to workers in offices without plants.

Now, a group of Korean researchers may have identified a mechanism for these positive benefits of indoor plants. (Kwang et al. 2008. Efficiency of Volatile Formaldehyde Removal by Indoor Plants: Contribution of Aerial Plant Parts versus the Root Zone. Horticultural Science 133: 479-627.)

Researchers from Korea's National Horticultural Research Institute examined the ability of Ficus benjamina and Fatsia japonica to absorb formaldehyde from the air. To study this, the researchers pumped formaldehyde into a container that held one of the two plants, or into a container that was empty. On average, containers with plants removed 80% of the formaldehyde from the air in only 4 hours. Containers without plants lost only 7% of the formaldehyde in 5 hours. Plant leaves reduced more formaldehyde during the day, while roots of reduced more formaldehyde at night. This suggests that formaldehyde is taken in through plant stomates during the day, when rates of photosynthesis are highest. The night removal of formaldehyde by the root zone suggests that soil microbes play an important role in formaldehyde removal.

Formaldehyde is a common household VOC (volatile organic compound) that is known to have negative effects on human health. In fact, VOC's, including formaldehyde, have been linked to 'sick building syndrome'.

What is the bottom line for the home gardener, or the party guest who is looking for a suitable hostess gift? Indoor plants will reap multiple benefits, not the least of which is better air quality, for the gardener or the gift recipient.