Recent research indicates houseplants purify indoor air by removing toxins from the environment. Stanley Kays, a University of Georgia professor of horticulture, and a team of researchers studied the effects of common houseplants on air quality. Kays and his team researched 28 species of plants and discovered certain plants removed volatile organic compounds (VOCs) from the air inside homes. Plants exposed to benzene, TCE, toluene, octane, and alpha-pinene demonstrated that they absorbed these toxins from the environment. Of the 28 plants included in the study, five of them scored excellent at improving indoor air quality.
Purple Heart Plant
The purple heart plant (Tradescantia pallida) scored number one at removing the four most common VOCs from the air. The deep purple foliage of purple heart bears three-petaled pink blossoms when exposed to bright, indirect light. It grows 4 to 6 inches in height and 12 to 18 inches in width. This trailing plant looks best in hanging baskets. It requires cool to average home temperatures from 55 to 75 degrees Fahrenheit in order to stay compact. Thirty percent, or higher humidity, keeps the leaf edges from browning.
Asparagus fern (Asparagus densiflorus) requires bright to medium light. Average temperatures from 60 to 75 degrees Fahrenheit and average humidity from 30 to 65 percent. Asparagus fern looks best in hanging baskets. When planted with blooming plants in the same pot, it makes attractive display. The bright-green foliage forms an arching mound.
Wax plant (Hoya carnosa), an attractive vining plant grows 3 to 4 inches in height and 4 feet wide. The waxy flowers emit a sweet honey scent. It requires high light and cool to medium temperatures from 55 degrees to 75 degrees Fahrenheit. The vining nature of the plant makes it excellent in hanging baskets or for training onto a topiary form.
Purple Waffle Plant
Purple waffle plant (Hemigraphis alternate) requires medium light and tolerates average to high temperatures from 60 degrees Fahrenheit and above and medium to high humidity from 30 percent and higher. It must be protected from drying winds and cold drafts. The plant grows 6 inches high and 18 inches wide. Its mounding form looks good in hanging baskets or standing pots.
English ivy (Hedera helix) requires bright indirect light during the summer and some direct sun during the winter. It prefers cool temperatures from 55 degrees to 65 degrees. Provide medium to high humidity from 60 percent and above. English ivy grows 6 to 8 inches high and 2 feet wide. This trailing vine looks best in hanging baskets or trained onto a topiary frame.