WINTER CARE OF HOUSEPLANTS
by Jerry Parsons, Ph.D.
Horticulture Specialist, Texas Agricultural Extension Service
in San Antonio
Now that the cold winds of winter have arrived,
people are keeping their green thumbs in tune with care and
culture of houseplants.
The custom of growing plants indoors is not
a new one. At a very early date, man learned how to grow plants
indoors during the long winter. These plants probably had
culinary or medicinal uses. Gradually, man came to grow house
plants simply for his own pleasure and enjoyment. Thousands
of years ago, homes were decorated with pots, jars, and baskets
containing living bits of nature.
Until about the middle of the eighteenth century,
the indoor gardener had only a limited variety of houseplants
from which to choose. Luckily, many rare and exotic species
were discovered through world exploration. Today, many hundreds
of species are available for indoor gardening.
The plants one chooses to grow should be readily
adaptable to its new indoor environment. The more nearly the
indoor conditions resemble the natural habitat of the plant,
the better it will grow. The plants should be compatible with
the existing decorating plan and act as room accents. Most
importantly, select healthy plants.
Light is the source of energy for plant growth,
so the amount and type of light available make it the first
consideration in choosing a place for growing indoor plants.
The length of the day has a great effect on metabolism - during
the fall and winter when the days are shorter, most plants
almost completely stop growing. Many homeowners who want to
decorate with growing plants don't have adequate light in
which to culture them. For those who want to try some houseplants
in low lighting, choose those which will tolerate such conditions.
These include the Chinese Evergreen, Spathyphyllum, Cast-iron
plant, Maidenhair Fern and Birds-Nest-Fern.
In addition to the shortness of the days, another
factor which contributes to the dormancy of many plants is
the diminished intensity of light in the winter. Plants will
not bloom unless the level of illumination is approximately
that of their habitat, although they may survive and even
grow quite well with considerably less light in many instances.
A southern exposure gets the most light and
is usually the best location for most plants. An east window
is the second choice because it receives the morning sunlight.
A western exposure can support many plants but afternoon protection
may be needed. A north window gets almost no directly sunlight,
but a good variety of plants may still be grown if they are
Temperature is also an important environmental
factor. Plants flourish much better at their natural temperature.
In almost every house, there are wide differences in temperatures
between rooms, and even between areas of the same rooms. For
example, window sills are almost always cooler at night than
the center of the room.
Humidity is the third important factor to consider
when growing plants indoors. The natural habitat of a plant
may have been very humid or very dry or somewhere in between.
The air in most homes is usually too dry in winter to support
many types of plants except succulents. The gardener must
then provide the additional humidity that the plants require.
There are several ways to increase the humidity
around houseplants: misting with lukewarm water, placing a
tray of water near the plants, and grouping plants close together
so that their combined transpiration will raise the humidity
The quality of the soil that the plants will
grow in is vital. Most plants grow well in the packaged commercial
soil mixes. Be sure to choose one that is high in organic
material and has been sterilized to kill insects, diseases,
and weed seeds.
The correct container is also important. The
height or diameter of the container should be from one-fourth
the height or width of the plant. Unglazed clay pots with
drainage holes are usually the best types to use because they
lessen the chances of overwatering.
The steps in potting a plant are simple, but
it is vital to the future plant to follow them carefully.
A plant needs repotting when a mass of roots develops that
presses against the wall of the pot. To remove a plant, hold
the root ball with your hand, turn the pot upside down, tap
the pot sharply, and the plant will slide out. The job is
much easier if the plant was watered thoroughly the night
before repotting. Place the plant in a pot one-half to one
inch larger than the previous pot. Fill the soil in gently
around the tender roots.
Of all the factors in the natural environment
of a plant, the most difficult to reproduce is the moisture
content of the soil. The amount of water a plant needs usually
depends on the temperature of the room, the kind of pot, and
the size of the plant. Be sure to soak the soil thoroughly
so that every particle is wet. Then, when the excess water
drains away, the soil will be uniformly damp and the roots
can use all of the available space. The best way to determine
how much moisture is in the earth is to touch it with your
finger. Avoid overwatering -the soil should be slightly dry
before the plant is watered again.
There are many easy to grow houseplants - for
instance Chinese evergreen, Cast-iron plant, Maidenhair Fern,
Birds-Nest-Fern, Sansevieria, Philodendron, Pothos, Spathiphyllum
and Zebrina to name a few that can be used. Some of the most
dramatic houseplants, however, are the various species of
palms. The Lady Palm (Rhapis excelsa) is a palm that can be
used outdoors in the shade and its shade tolerance also makes
it an excellent indoor palm. It's rather slow growing and
large specimens can be expensive, but it is a beautiful palm
well adapted to indoor conditions. The Pigmy Date Palm (Phoenix
roebeleneii) is often used as an indoor palm and unlike its
huge relative that produces the commercial dates it is more
adapted to home conditions. Fountain Palm (Livistonia chinensis)
is a palm that will grow in protected locations outdoors here
and has huge, bright-green fan-type leaves. It would be an
excellent plant to use in an atrium. The European Fan Palm
(Chamaerops humilis) is quite hardy outdoors going as far
north even as central Texas, but it can make an excellent
indoor palm as well. With age it tends to form multiple trunks
in cluster fashion. One of the best of the indoor palms available
on most seed racks and is the best to use for ornamental use
since it produces several blooms with much better than some
other palms, especially the often sold Areca Palm.
There are many good houseplant fertilizers on
the market. Frequent fertilizing is necessary because the
soil rapidly loses many of its nutrients through frequent
watering. However, overdoses of these fertilizers can cause
weak stems, lanky growth, and even death. Read the label and
follow the directions! Don't overdo the fertilizers! In fact,
if the light intensity is low, it would be best not to fertilize
from October 15 until March 15.
By providing the correct natural environment
including light, temperature, and humidity and by careful
potting, watering and fertilizing, you can grow beautiful
healthy plants. Finally, some of the few good imitations of
real plants have been several of the artificial palms. If
your thumb isn't the least bit green, or if you need a plant
for a dark hallway, these might be permissible.
For more information about many types of houseplants
and pictures of each, see: