THE DETAILS: Swedish and Norwegian researchers analyzed more than 20 studies focusing on plants and their psychological benefits and found that many studies linked houseplants with positive benefits, including improved performance in an office or classroom, increased pleasantness, lower anxiety, and lower blood pressure. No studies registered negative effects related to indoor plants, although a few studies did not show significant mood improvement.
WHAT IT MEANS: While the researchers call for more studies looking at indoor houseplants and mood, there's plenty of evidence suggesting they benefit us in many ways, whether in the home, classroom, office, or even a hospital room. In fact, they seem to help us heal. A study published in the September 2008 issue of the journal Preventive Medicine found that patients in a hospital room with a plant reported less stress when compared to those in plant-free rooms. Another study published in 2008 suggests that hospital patients recover faster and use fewer painkillers when there's a live plant in the room.
A well-cited NASA study from the 1980s determined that several common houseplants also have the power to rid your air of harmful volatile organic compounds that gas from paint, furniture, and other building materials made of plywood. A more recent study found these common plants can also remove harmful, lung-irritating ozone from indoor air.
Here's how to enjoy the benefits of houseplants without spending lots of green.
• Score free plants. Sure, you can usually find houseplants at the local nursery or grocery store. But before breaking open your wallet for an all-natural air-purifying plant, ask around to see if you can score unwanted houseplants. Search freecycle.org to ask for unwanted houseplants, or ask neighbors or relatives if you can snag a cutting. Rodale.com's Nickel Pincher suggests you snip four to six inches off the tips of growing shoots, remove the lower leaves and any flowers, and stand the cuttings in a jar of water. Once its new roots are about an inch long, you can plant the cuttings in potting soil. Pot them in recycled or reused containers…just make sure there are a few drainage holes on the bottom.
• Opt for the gold-star air cleaners. When it's time to pick a houseplant, go with one that science has shown is one of the top air-cleaning indoor plants. These include areca palm, reed palm, dwarf date palm, Boston fern, English ivy, Australian sword fern, peace lily, rubber plant, weeping fig, along with snake plants, spider plants, and golden pothos. If you're a first time plant-keeper, consider placing golden pothos in the bathroom, because this air-cleaning plant does well in low-light, humid conditions. Or try a snake plant, below.
• Propagate the houseplants you have. Snake plants, also known as mother-in-law's tongue, are virtually kill-resistant, so they're good to start with if you're not much of a horticulturist. They require very little light and can endure comparatively long periods of time without water. You can actually propagate them relatively easily. Cut off an entire snake plant leaf, and then cut the leaf into two- to four-inch sections. Fill a tray with moist sand, and stand the cuttings in the sand. Loosely drape some transparent plastic film over it to trap moisture—stick pencils or chopsticks in the sand to hold up the plastic. After about two months, transplant each growing plant into its own pot. For more on propagating plants like this, check out the Plant Propagator's Bible (Rodale, 2007).
• Prevent a plant kill. If you're notorious for murdering houseplants, don't be deterred from trying again. Here are some tips from our colleagues at OrganicGardening.com:
1. Understand the light factor. Make sure you match your plant's light needs with the right indoor environment. A plant requiring high light will do best in front of most south-facing windows, or large unobstructed east or west windows. North-facing windows and any shaded windows are good places to place low-light plants.
2. If you're buying a plant at a store, look it over to make sure it's not diseased or infested with pests. Those are visitors you do not want to welcome into your home. If leaves fall off with a gentle tugging, the plant could be unhealthy.
3. Water right. Push your finger an inch into the pot's soil; if it's damp, don't water, but check back in a few days. If it's dry, water it. When it's time to water, provide a thorough soaking so that a little water comes through the pot's drainage hole and into the saucer below. For more tips on caring for household plants, visit OrganicGardening.com.