Thursday, January 23, 2014

Low Humidity Problems and Indoor Houseplants by Carol King

Spider Plant Chlorophytum comosum
This time of year, we Colorado gardeners turn to indoor plants to soothe our gardening souls.  However the indoor environment in our homes can be very harsh for many plants. Many of our house plants are native to humid, tropical rain forests and require special consideration when they reside in our Colorado homes. While lighting and temperatures need to be monitored for successful indoor gardening, humidity is the big issue during colder months.  Heating systems common in Colorado circulate dry, warm air throughout the house. Our indoor environment often has less than 10 percent humidity. This is a drastic reduction from the 70 to 90 percent relative humidity levels found in the native climates of most tropical plants.

Why does this matter? Humidity is the level of moisture in the air and can affect a plant's need for water.  Plants grown indoors with low humidity lose more water through transpiration, so their root systems require more water. In addition, plants located near heating or cooling vents may develop leaf spots or brown tips.


Here are a few tips to help alleviate low humidity problems:
  • Misting plants may help alleviate this condition, however, it must be done frequently to be effective, and it may promote some foliar diseases. 
  • Place several plants together on a tray filled with gravel. Filling the tray with water provides the humidity many plants need. Make sure the bottom of the container does not stand in water; the soil will become water-logged and cause root damage. 
  • Using a humidifier or hosing down the floor around your plants may also help.
  • For house plants with moderate humidity needs, grouping them together during the heating season is a simple solution. Each plant gives off humidity through transpiration. Clusters of plants will create very good humidity in the surrounding air.
For more information see this  Planttalk Colorado Fact Sheet.