Leafy Clean: NASA-sanctioned houseplants purify indoor air


| March-April 2009



Air Purifying House Plants

image by Huan Tran

You don’t need exotic technology or expensive gadgets to remove pollutants from the air you breathe indoors. According to NASA studies, a selection of hardy, easy-care houseplants can help.

NASA has been researching methods of cleansing the air so that future space stations can be kept fit for human habitation for extended periods of time. Researchers have discovered that many common houseplants “scrub” significant amounts of harmful gases—such as formaldehyde and benzene—out of the air through photosynthesis, absorbing pollutants and rendering them harmless in the soil.

These findings are especially relevant for inhabitants of newly constructed buildings, which are sealed tightly to conserve energy but consequently trap pollutants indoors. NASA researchers recommend that you have a minimum of two plants per 100 square feet of floor space in your home or office. Best of all, you don’t need to be a green thumb to incorporate these popular, low-maintenance houseplants into your environment.

Chinese evergreen. Chinese evergreens are tolerant plants that do well in a variety of settings and flourish for years with minimum care. They do best in shadowless light, such as a north-facing window. Keep the soil barely moist.

Dracaena. Dracaenas grow slowly and retain their foliage for long periods of time. Plant them in regular potting mix and keep the soil moist, but don’t let the pot sit in water. They grow best in bright, indirect sunlight, warm temperatures, and low humidity.

Heartleaf philodendron. Philodendrons grow better than most other houseplants under adverse conditions. They do well as long as they’re kept warm, moderately moist, and out of direct sunlight.