It’s tough being a houseplant during the winter, especially during the holiday season. Besides reduced light levels and low humidity, you have to give up your favorite spot near the window to seasonal plants like poinsettias, Christmas cactus, and amaryllis. If that’s not enough, you’re often faced with a caregiver who’s intent on watering you like a holiday plant: too often and too much.
The result of this treatment often causes houseplants to meet the Fate of most of their holiday kin: the top of the compost heap.
To avoid the Fate of recycling your houseplants, you may have to make a few adjustments to their indoor accommodations. Because the winter sun is lower and farther to the south, plants receive fewer hours of less intense light. So, houseplants that were exposed to low light on the north side of the house can be moved to east-facing windows. Plants near east-facing windows can be exposed to more sunlight by moving them to a south-facing window. Plants that were located on stands away from direct sunlight can be moved closer to a less exposed window to give them more light. In dimly lit rooms, rotate the plants every week or so.
Low moisture levels in the home during the winter can be uncomfortable to us and harmful to some houseplants. Relative humidity levels of 10 or 15 percent indoors can be tolerated by cactuses and succulents like snake plant (Sansevieria), cast-iron plant (Aspidistra), and various dracenas. Most others need a relative humidity of 40 to 60 percent. When exposed to these low moisture levels during the winter months, the leaves of most plants lose water faster than their roots can absorb it. As a result, the leaves curl, their tips turn brown, and flowering plants may drop their flower buds or flowers may wither up prematurely.
Move sensitive plants to cooler locations or to rooms that tend to be more humid than others such as the bathroom, kitchen (away from the oven), or a well-lit basement.
You can boost local humidity levels in the following ways:
- Water lost by leaves and potting mix raises moistens the air of its neighbors.
- Using a room humidifier or cool-mist vaporizer. Track humidity levels with a digital hygrometer so you can increase levels that will match your comfort, too. The ideal moisture level for people is between 30 percent and 50 percent relative humidity.
- Setting pans of water on radiators or wood stoves.
- Placing high humidity lovers on a pebble-filled tray of water inside an aquarium tank with an adjustable opening at the top. A small fan will improve air circulation and a heating cable under the tray will speed up evaporation.
One final tip regarding winter houseplant care is to avoid overwatering: the biggest cause of plant death during the winter months. Water according to the needs of the plant. Plants that are resting should be watered sparingly. Keep flowering plants moderately moist and watered when the surface of the medium feels dry.
Winter and the holidays can be a challenging time of year for both plants and people alike. However, by offering our houseguests a little attention now will help them realize the destiny we prescribed for them: to brighten our homes with their presence…next Spring.
Bob Polomski (c) 2014