People claim they have purple thumbs more often than not when it comes to houseplants. I am one of these weary folks.
Gardens are fine. I am happiest in the midst of greenery and humusy soil. But come winter, while trying to save a few herbs, I watch helplessly as things wither away. Once I had a house full of plants I'd propagated from cuttings, but when I moved to Idaho I lost them all except one, a sansevieria, a plant so determined to live that one of its common names is Mother-in-law's tongue.
People will still choose to not have plants inside because they expect them to die—but consider the health benefits. Plants breathe carbon dioxide, which we exhale, and in turn they exhale oxygen, which we need to breathe. Therefore, plants freshen air, add energy and help remove toxins and chemicals. As with we big, bumbling humans, the most important elements a plant needs to thrive indoors are water, air and light.
Inside our homes over the winter, this aspect of plant health is not always easy to come by. According to Leslie Land and other New York Times "Garden Q & A" columnists, it's important to try to reproduce a plant's native home.
"In a house, dormancy is induced naturally by shorter days, or by your withholding water or putting the plant in a dryer spot. Growth slows, and the plant needs less fertilizer and water."
Since heated rooms tend to be dry, especially with forced air or fire, you should keep temperatures comfortable but as low as possible. Temperatures above 67 degrees will severely affect indoor plants since the humidity drops as temperatures rise. At night, close curtains or move plants if they are next to windows, as glass can be a cold and harsh neighbor.
You might consider, as I have, acquiring an air purifier or humidifier, as long as it's kept nice and clean. Leaf loss or yellowing is often caused by lack of humidity. Plants create a certain amount of humidity themselves through transpiration through leaves, from the soil, and even the pots if they are porous. The more plants you have in a room, the higher the humidity will be, and the plants are placed close together. They will be able to benefit each other.
Setting the pots onto a bed of small pebbles and gravel in a shallow tray with water in the tray raises the humidity without giving the plants "wet feet." Except for fuzzy-leafed plants such as African violets, houseplants enjoy a daily misting with room-temperature water. Placing water-filled vessels around the room will also add to the moisture in the room.
If all else fails, try a cactus. There are so many fascinating shapes, colors and sizes of these plants that, by themselves, they can turn a room into a virtual desert terrarium.
