1) Whether flowering or just showing us their leafy side, plants make us happy. Three different studies have shown that people receiving flowering plants always elicit what psychologists call the Duchenne, or true, smile.
2) Plants produce life-giving oxygen while absorbing harmful carbon dioxide.
3) Plants give off water. Notice how dry your skin feels in the winter when the central heating is on? Plants transpire, releasing up to 97% of the water we provide them, increasing the humidity in our dry homes. Schefflera is particularly effective in increasing humidity.
4) Houseplants may seem like just a pretty accessory, but they're actually working hard to absorb volatile compounds (benzene, formaldehyde, etc). With so much emphasis on new buildings being "tight" and energy efficient, many now retain more of these toxic compounds. One study found that as few as fifteen houseplants (6-8" diameter pot size throughout a house removed 87% of the toxins in an 1800 sq. ft. home in one day!
5) Plants have a calming influence and actually reduce stress. Studies have shown that the presence of plants in the indoor environment lowered blood pressure readings as well as reduced headaches and fatigue.
6) Parents - plants can actually increase learning. European research found university attendance improved, test score rose, and behavioral problems were reduced by more than 60% in classrooms with plants as opposed to sterile, "nonplant" environments. Kids - your parents can have up to 12% quicker reaction time on a computer task in a room with plants.
7) Families with small children and loud pets - plants with large leaf mass and "harder" leaf surfaces (Ficus, Spathiphyllum, and Dracaena, for example) cut noise pollution by absorbing and reflecting noise. This is especially true in rooms with hard surfaces (marble walls, stone floors). For maximum benefit, try small groupings around the room than a single large one. Also, place these groupings in corners rather than in the center of the room.
8) More health benefits from a greener living or work space? Scandinavian studies have shown that houseplants can reduce coughs, sore throats and other cold related illnesses substantially - more than 30%!
9) Ever think of interior landscaping specifically for personal health reasons? Bromeliads, many orchids and easy-to-care for succulents (think Jade Plant) intensify their oxygen production/carbon dioxide absorption cycle at night. Consider these for your bedroom.
10) Have a friend or family member just home and recuperating from a hospital stay? The inclusion of plants, flowering or foliage, inside the patient's room dramatically reduced: anxiety, recovery time, pain, and the number of minor post-surgical complications.
This list of proven benefits doesn't even address the real reason we buy plants in the first place - to set a mood, to create a special look, to just make us happy. Enjoy them for those "emotional" reasons and reap the huge physical benefits they also provide.