Cold weather means that most folks have their homes closed up and the
heat on. After a while, the lack of moisture in the air becomes quite
noticeable to the occupants, especially the houseplants. For those
plants that prefer a high level of humidity, the low humidity commonly
found in homes in winter can be a shedding experience as their foliage
yellows, dries up, and falls off.
Houseplants do best at a relative humidity of 70 to 80 percent, a level
that is often difficult to maintain in the home. Any increase in
humidity will help plants, however, especially if the dwelling is heated
by a wood or coal stove or fireplace.
One way to help increase the humidity around plants and keep them healthy
and growing is to use humidifiers when available and practical. It's
also important to avoid raising the air temperature too high. With
a given amount of water in the air, the higher the air temperature, the
lower the relative humidity.
An inexpensive way to raise the humidity is to place pans of water on
stoves or radiators to act as humidifiers. A gravel-filled tray partially
filled with water also works well. Just place your potted plants
on top of the gravel. The humidity will be increased in the immediate
area of the plants. But do not allow the bottom of the pot to come
in contact with water as this can lead to a waterlogged soil ball that
could kill the plant.
Move humidity-loving plants to the kitchen or bathroom. These
rooms usually have higher humidity than the rest of the house. Or
make a grouping of plants. This will form a microclimate with a higher
humidity. And keep plants, especially ferns, away from wood stoves,
fireplaces, and heat registers.
Many people mist their plants. This is okay, but avoid prolonged
misting. A film of water on the foliage is often all that various
fungus spores need to germinate.
A general rule of thumb to follow if you don't know the humidity requirements
of a plant is that the lower the light requirement, the higher the humidity
requirement.
-----------------
University of Vermont
| 
What is hot:
