by Jerry Parsons, Ph.D.
Horticulture Specialist, Texas Agricultural Extension Service
in San Antonio
The first thing to consider in selecting a plant
for interior decoration or indoor landscaping is the desired
Cut-flowers in an arrangement are temporary,
while the majority of flowering plants in containers are used
for a somewhat longer time, or until their blooming period
is completed. Think of the plants you select for your interior
as a fixture that is as much as the permanent décor
as draperies or paintings. However, this comparison will have
limitations since paintings and sculpture require no care,
except occasional cleaning or dusting. However, indoor plants
will grow larger and sometimes even outgrow their surroundings
What are the qualities of a good plant for
an interior landscape- First, it must be vigorous and strong,
and be able to withstand more adverse conditions than the
average outdoor plant. Indoor areas have more challenging
conditions for excellent growth, such as minimum light and
rather inadequate ventilation. Inside, night temperatures
are warmer, there are drafts and the atmosphere is drier.
While all of these environmental factors may be controlled
to a certain extent, they're always present and eventually
a delicate plant will succumb to these conditions.
The second important characteristic of a plant
well suited for inside is that it should be evergreen, since
it will be seen everyday throughout the entire year.
In addition to being evergreen and robust, plants
selected for indoors must also be attractive. While most of
these plants will flower from time to time, the major appearance
considerations are directed toward the plant's foliage and
how the plants grow. The leaves may be selected for their
color or form, or both. The growth habit (form and shape)
of these plants should be attractive and require the most
minimum of maintenance.
Many plants suitable for indoors have variegated
leaves. When these plants are selected, the inside light intensity
must be greater than the light required for plants "plain"
green leaves. Variegated foliage needs more light in order
to retain its bright and striking color contrasts. The leaves
of many tropical foliage plants specially adapted to indoor
conditions can, of course, be very fascinating with no more
color than the natural green color of their leaves. In many
instances, the size, texture and surface of the foliage is
its most attractive feature. Most plants that are best suited
to indoor success thrive in medium- to low-light intensities.
For best results, select plants that are slow-growing.
They will perform well over a longer period of time without
a great deal of pruning or training. Some of the easiest house
plants to grow include:
Heartleaf Philodendron: Philodendron oxycardium
(cordatum). While most of the philodendrons are easy to grow,
this is the easiest. The name Philodendron is derived from
the Greek language and it means tree-loving. Therefore, it's
not unusual to find climbing forms of Philodendron such as
Heartleaf trained on "totem poles" made of bark
or osmunda fiber.
Devil's Ivy: Scindapsus aureus. This plant
looks a lot like a variegated Heartleaf Philodendron and,
in fact, it is often called "Philodendron". To further
confuse matters, it is also called Pothos. Whatever you call
it, it is easy to grow. The best variety of scindapsus is
'Marble Queen'. Many times the leaves of this variety are
so variegated that they are almost white. This variegation
is more intense in good light.
Chinese Evergreen: Aglaonema commutatum. This
is an excellent plant that is not used enough. Of all house
plants, it is perhaps the easiest to grow and some of the
newer varieties are very attractive. The standard Chinese
Evergreen is a bit dull with green arrowhead-shaped leaves,
but the variety 'Silver Queen' is striking.
'Janet Craig' Dracaena: Dracaena deremensis
var. 'Janet Craig'. There are many dracaenas suitable for
use in the home, but this is one of the best. All members
of this genus may occasionally have dead, brown leaf tips
due to low humidity. However, on 'Janet Craig' it is not that
noticeable. This plant may even be tougher than the Chinese
Spathiphyllum: This is the so-called "closet
plant" that is very tolerant of low-light indoor conditions,
even though it will not grow in a closet!
Arrowhead Plant: Syngonium or Nephthytis. It's
a tough plant with both green and variegated forms available
Cacti and Succulents, such as Aloe and Euphorbia
are fine if you have lots of light.
Wax Plant or Hoya is a very durable, vining
"Red Bird": Pedilanthus is a waxy,
Swedish Ivy: Plectranthus is an apple-green
plant that makes a nice hanging basket
Don't forget to dust and prune your house plants
during the summer months. In the winter, dust from the heating
system can coat the leaves, clogging the pores (stomata) through
which the leaves breathe. In the summer, when windows are
open, there is even more dust in the air to collect on plant
Dust can be removed in several ways. A damp,
soft cloth or sponge is good for plants with large leaves.
Ordinary tissue will also do, but be gentle so as not to bruise
the leaves. Another method is to mist plants, or give them
a tepid shower in the bathtub or sink. To prevent soil from
washing out of the pot, wrap a piece of plastic around the
base of the plant and pot.
Pruning is also a good idea. It keeps the plant
at the size desired and improves its shape. Remove the browned
tips of leaves or leaves that are yellowing. These can occur
even on healthy plants, primarily in the winter. Plants with
thin, sharp tips such as Dracaena, spider plant, aspidistra
and ferns suffer most. When the edges of leaves turn brown,
snip them, following the shape of the leaf and repeating as
often as necessary. Water plants when needed. The leading
cause of most house plants deaths is over-watering. Simply
check the plant weekly by using the most tried-and-proven
technique-- the finger test. Simply place your index finger
knuckle- deep into the potting soil. If you feel moisture
--DON'T WATER! But if the mix is dry, completely saturate
the potting soil.
House plants also respond to soil aeration.
Loosen the soil with a kitchen fork to help the roots get
air. This also helps to get rid of the mold that sometimes
collects on the surface of the soil when plants are kept too
moist or in poor light. A generally recommended feeding program
includes using a water-soluble fertilizer once every 6 weeks,
as well as a slow release fertilizer (Osmocote) every 6 months
as a top dressing in the pot, or mixed into the potting soil
when plants are transplanted into larger pots.
Occasionally, house plants may suffer insect
problems. Controlling insects such as aphids, mealybugs or
spidermites may seem to be a never ending battle, but the
use of a systemic insecticide containing Di-Syston granules
as a preventative measure will help. Follow the product label
directions and cautions.
Sometimes people think that living house plants
are not worth all the bother. Think again. The use of non-biodegradable
plastic plants defeats the whole goal of beautification. It
adds to pollution. The only difference between a plastic plant
and a plastic carton is size. Real IS best!
For much more information about interiorscape
House Plant Care
The most frequently asked question about house
plants is "Why does the bottom foliage of my houseplants
turn yellow and then drop?" There is no concrete answer.
Leaf drop associated with plants is usually due to improper
The cause may be one or a combination of factors.
In all, there are about 10 common causes of leaf drop.
The first is improper light. Insufficient natural
light or perhaps too light intensity that is two great, possibly
causing scorching and then eventually, leaf drop. This may
be particularly true in plants of the Ficus Family.
The second cause of leaf drop is shock at transplanting.
Transplanting will ultimately lead to stress and stress leads
The third cause is a sudden change in temperature
or light, which also causes shock. Always be familiar with
the light requirements of your plants and try not to make
changes. Most sudden changes in temperature and/or light occur
when we move plants from indoors to outdoors or vice versa.
The fourth cause is too much fertilizer. We
seem to live with the idea that a little will do a little
good and a lot will do a lot of good. This is just not so
when it comes to fertilizing. Seldom will under-fertilization
lead to leaf drop.
Drafty locations will be the fifth cause of
leaf drop. Therefore, placing them under or around air conditioning
and heating vents should be avoided.
Sixth is gas fumes. Leaky space heaters or stoves
using natural gas, butane or propane can also cause severe
leaf drop in ferns. Also, severe infestations of insects and
diseases may cause leaf drop if allowed to spread uncontrollably.
Check plants frequently for insects and diseases and treat
promptly if needed.
Packed soil due to infrequent repotting and
improper watering may lead to leaf drop. In this case, leaf
drop may be the result of a lack of oxygen. Repotting will
help correct this problem.
Finally, the tenth cause of leaf drop is moisture
fluxuations. This can easily be corrected by following a schedule
of frequent, light applications of water.
There are a number of insects that attack our
house plants. Many times we bring them in when we move our
plants indoors after repotting, watering, or airing-out period
outdoors. Just about all of the common houseplant insects
are sucking types. These include mealybugs, spider mites,
aphids and scale insects.
Mealybugs are soft-bodied, oval insects with
well-developed legs and segmented bodies that are covered
with powdery wax. Many mealybug species have flat bodies with
pointed sides and tail-like filaments. The adults and the
nymphs feed in compact groups. They suck juices from leaves,
stems and roots of our house plants. Mealybugs may be controlled
using diazinon or Malathion with 1/4 teaspoon of a liquid
dish-washing soap, or, you might like to try the insecticidal
soaps now on the market for control of mealybugs.
Spider mites, which include the 2-spotted spider
mites and red spider mites, are some of the most destructive
pests of indoor plants. These tiny bugs feed underneath the
leaves and are known for spinning fine webs along veins and
leaves. They are considered sucking insects and in severe
cases can cause chlorosis and stunting, eventually leading
to death. For control, 2 chemicals are widely used for severe
cases, Malathion and Kelthane. Kelthane is a miticide and
may be most effective. Before applying these or any chemical,
read the directions for specific instructions. Where spider
mite infestations are not too severe, insecticidal soap and
water may be used to eradicate or retard infestations. To
use soap and water, take the plant outside and cover the container
with aluminum foil to keep from losing the soil. Turn the
plant to its side and, using a sprayer ,thoroughly apply the
soapy solution to the underside of the leaves. Afterwards,
wash with clean water. See your local garden center for more
detail on insecticidal soaps.
Aphids and scale are 2 additional insects that
plague indoor houseplants. Aphids are commonly greenish-white
but may also be brown, red or black. They are sucking insects
and are normally found on the undersides of leaves and tips
and shoots of young tender plants. They can cause chlorosis
and stunting and may even lead to leaf drop and death of the
Scale insects are also sucking insects and
are found on nearly every part of the plant. Young, immature
scales in the "crawler" stage are found on the underside
of leaves and the tips of plants. As they mature and become
stationary with their waxy coat, they are normally found on
older leaves and stems. Control of both aphids and scale include
using insecticidal soaps, Malathion, diazinon and pyrethrins.
Always treat plants outdoors and then bring
them in after the chemical has dried. Treat all plants including
the soil before they are brought in for the winter, and check
the undersides of pots and trays for centipedes, millipedes,
snails, slugs, sowbugs, and pillbugs that may be harboring