As horrendous as this winter has been, I've maintained some semblance of sanity by tending to my houseplants even while snow is piling up outside my door. I've had the same jade plant keeping me company for many years and another unknown plant in a bizarre deer head planter that I found at a flea market in upstate New York. I've recently added some "air plants" to my collection, as well as a beautiful moth orchid (phalaenopsis) that was intended as a gift but I just couldn't part with. We also received a beautiful palm a few years ago as a housewarming present that currently brightens up a corner of my living room.
Sometimes I feel overwhelmed with my houseplants and I purge the ones that aren't doing so well. I fear my house will end up looking like a 1970s real estate office if I don't edit myself every so often. However, I recently discovered that my houseplants are not only giving me a much-needed dose of greenery in winter, they are also helping to purify the air in my home.
According to a 1989 study by NASA and the Associated Landscape Contractors of America (ALCA), houseplants are actually proven air purifiers and can help to absorb some of the nasty chemicals that unfortunately reside in our homes, specifically formaldehyde, benzene and trichloroethylene.
Formaldehyde is found in many building materials including particle board and foam insulation, as well as cleaning products; benzene is found in oils and paints; trichloroethylene is used in paints, adhesives, inks and varnishes.
The 1989 study of these 3 chemicals was originally intended to find ways to purify the air for extended stays in orbiting space stations, but the test ended up having implications for life here on earth as well. The study found English ivy, gerbera daisies, pot mums, peace lily, bamboo palm, and Mother-in-law's Tongue were the best plants for treating air contaminated with benzene. The peace lily, gerbera daisy, and bamboo palm were very effective in treating trichloroethylene. Bamboo palm, Mother-in-law's tongue, dracaena warneckei, peace lily, dracaena marginata, golden pathos, and green spider plant worked well for filtering formaldehyde.
For an average home of under 2,000 square feet, the study recommends using at least fifteen samples of a good variety of these common houseplants to help improve air quality. They also recommend that the plants be grown in six inch containers or larger.
Many houseplants are of tropical origins, making them perfect specimens for indoor gardening. They generally do well with bright, indirect light, so an east facing window sill is perfect for them. Some plants, such as orchids, are a bit more finicky and may require some tweaking of your indoor climate. Orchids, for example, require higher amounts of humidity than you might have in your home, especially in the dry winter. I use a spray bottle and spritz the air around my orchid in the morning to give it some humidity. You can also use a humidifier in the room where you keep them, or a tray of rocks with water on a radiator can also do the trick.
Orchids are a type of epiphyte or "air plant" which don't require soil to grow. They have roots that take their nutrients and moisture right out of the air around them. Other epiphytes include Ionatha, Bulbosa and Stricta. These non-orchid epiphytes require a full soak every week for 30 minutes, and bright indirect light. They are one of the easiest, low-maintenance plants you can buy and they are very unique looking.
A common mistake people make with houseplants is overwatering. When you buy the plant, read the care instructions carefully. Many plants only require water once a week. I usually let the soil dry out some between watering, and I water less in the winter to mimic nature. Unfortunately, the signs of overwatering and underwatering are very similar (wilting and discoloration) but overwatering will probably kill your plant more quickly than underwatering. Your houseplants will also want some food about once a month. I like to use a balanced fish emulsion, but it tends to be a bit stinky so you can also use a synthetic variety if you want.
Your houseplants will do well outside once the weather turns, but be sure to give them a few days to get used to the outdoors. I bring my plants out in the morning and put them in a shaded area and then I bring them in at night. After a week of this, my plants are ready for the summer outside. Before I bring them back inside in the fall I cut them back, spray them with an insecticidal soap, and pick off any critters that may have made their home in the plants (check the soil too!) The first few weeks inside are usually a shock, but the plants make it through the winter and help me make it through too!