Houseplants: beating the winter blahs

By Deb Brown

From eNews, February 24, 2005

During the winter months, the indoor environment can be especially hostile to houseplants. Days are shorter, limiting the amount of light that's available for photosynthesis. Cold air near windows and doors can damage tropical plants. Air becomes drier as furnaces kick in more frequently, and insect infestations may flare out of control.

Yet, despite these potential pitfalls, you can keep most of your houseplants looking healthy. So that, come spring, they can begin to perk up on their own.

• To compensate for the fewer hours of daylight, move your houseplants to brighter locations around your home--but remember, not too close to icy cold windows--or you can supplement natural daylight by placing fluorescent lights about a foot from your plants.
• The more you heat your home, the drier the air becomes. If the humidity level is too low, plants may lose water faster through their leaves than they can replace it through their roots. The symptoms of this include browning leaf tips, yellow leaf margins, and buds dropping or wilting. The simplest way to deal with low indoor humidity is to pay attention to the watering of your plants.
  
  Watering tip: Allow the water to come through the container's drain holes before you stop. Pour away any excess moisture that has collected in the tray or saucer, and check the soil regularly to determine when to water it again.
• Spider mites and houseplant insects reproduce rapidly in a warm, dry environment. To prevent or control an infestation, increase the humidity level in your home by installing a humidifier. These pests are also drawn to dusty foliage, so keep your houseplants clean and dust-free by wiping them down periodically with a soft, damp rag. Common signs of insect activity include fine webbing, cast skins, and shiny, sticky residue.

Deb Brown is a horticulturist with the University of Minnesota Extension Service.