INTERIOR PLANT CARE
Section G
INTRODUCTION
Growing and maintaining
plants indoors has been a source of enjoyment and beauty for generations. Foliage plants make homes and offices more
attractive throughout the year. They impart
an atmosphere to a room that can be achieved with few other accessories. Growing and caring for interior plants offers
a new and exciting hobby for anyone who likes to work with living things and
see them grow.
Interior plants vary in their
ability to withstand the adverse conditions found in most homes, offices,
buildings and malls. For example, most
rooms have low light, low humidity, and drafts that make the room unsuitable
for good interior plant growth. Plants
grow much better in a greenhouse where these environmental conditions can be
controlled. However, by selecting plants
that are more tolerant to adverse conditions, it is possible to have beautiful
interior plants the year around. The
purpose of this article is to examine the criteria necessary for the successful
management and care of interior plants in offices, buildings, malls, and homes.
PLANT SELECTION
Buying Interior Plants
When buying
interior plants, make sure that you are looking for healthy, bushy, vigorous
plants. Stay away from limp or leggy plants. Do not buy plants that have yellow
leaves. Usually this is a sign that the
plant is not getting enough light, is too old, or is having some kind of root
or disease problem. Check the plant for
insects by inspecting both the underside and upper sides of the leaves.
Check the stems as well. By looking only at the top of the plant, you
cannot always see the insects that may do the damage.
What is a Healthy Plant?
A healthy plant is one that
is fairly full, has a dark green color to the leaves, and is well branched (if
it normally branches). A long, tall
plant that does not have a good foliage canopy is usually one that has been
kept under low light for too long, has had problems in growing, or does not
have the root system that it needs. An
exception to this may be very large Dieffenbachia or Dracaena. These plants tend to lose some of their lower
leaves as they get older. However, you
still want to look for plants that are full of leaves and have plenty of fresh
growth.
One thing to avoid is a plant
that has tender, young growth. If such a
plant is placed in a darkened room, the new tender growth will be the first to
deteriorate. Make sure that the plant is
not a very old one, because this can cause problems.
To better serve your
customer, you should acquire the knack of spotting healthy, good quality
plants. To a lot of people, the biggest
is the best. There are several clues to
a plant's health, but size is not always one of them; shape is, however. Choose plants that are short and stocky
rather than long and leggy. Leaf color
is another quality to check. Look for
lush foliage instead of pale, faded leaves.
Remember, too, that leaves without insect bites are not necessarily pest
free. Check the stems and underside of
the foliage for brown spots and insect webs.
Look for white or yellow dots.
Become a plant critic. Make sure
the plants you buy and sell are healthy ones!
Transportating Interior Plants
When transporting interior
plants, remember the two seasons of the year that can cause damage to the
plants, the hot summer and cold winter.
In the summer, avoid placing the plant in a vehicle and leaving the
vehicle closed. Heat will build up and
may possibly destroy the plant. This heat
build-up can occur in a very short period of time.
If you have to set the plant
near a window in the vehicle where the sun is shining directly on the plant,
make sure that the plant is covered with newspaper. An alternative would be to cover the window
by placing paper so that the sun will not shine directly on the plant. If traveling for any distance, this is
extremely important. Plants can be
burned by the sun shining through the glass in the vehicle even though the air
conditioner is on and you are comfortable.
During the winter months,
make sure you insulate the plant thoroughly before leaving the store to carry
it to the vehicle. This may be done by
wrapping the plant in newspaper, plastic, or special plant sleeves designed for
this purpose. In severe weather, even a
short run from the store to the vehicle may be sufficient to injure the
plant. If the plant is properly
insulated and protected, this is not a problem
Make sure that the plants are
placed in the vehicle with the heater on.
Do not place them in an unheated trunk compartment as this is usually a
very cold area. If the plants are
wrapped carefully and placed in the front or heated part of the vehicle where
the temperature is comfortable, they will survive the delivery trip.
ENVIRONMENTAL FACTORS THAT INFLUENCE PLANT GROWTH
Light, temperature, water,
humidity, fertilizer, containers, and soil mixes are chief factors that affect
plant growth. Any one of these in the
incorrect portion or of the wrong type will prevent proper growth of interior
plants. Each of these factors will be
discussed in the following portion of this article. Suggestions will also be made on how to
manipulate them to get optimum plant growth.
Light
The growth of interior plants
and the length of time they remain attractive depend on the amount of light
they receive in relation to how much light they need. Light is necessary for all plants because
they use this energy source to manufacture food.
Inside, we often must
supplement light by using incandescent or fluorescent lights or by placing the
plants near a window. Some interior
plants, especially ones that have been indoors for a long time, cannot tolerate
extended periods of direct sunlight. For
this reason, it is best to locate interior plants in or near windows that get
direct sunlight for only short periods of time.
Do not, however, put plants in dark corners. Indirect light is best for most interior
plants.
Flowering plants such as
gloxinias, geraniums, and begonias prefer bright,
indirect light. Place
them in areas that will receive this light level. East facing windows are good for these
plants.
Excessive light can be as
damaging as too little light. When a
plant gets too much direct light, the leaves may become pale, sunburn, turn brown,
and die. Therefore, during the summer
months, protect plants from too much direct sun
light.
Remember, also, that the sun
is lower in the sky during the winter.
Tender plants such as ferns may sunburn during the winter months. With the sun lower in the sky, many windows
will receive more hours of direct sunlight during the winter months.
Temperature
Most interior plants tolerate
the normal temperatures found in homes and offices. The ideal temperature is 70 to 80 F in the day
time and 60 to 65 F at night. Many
flowering plants will keep their flowers longer when the night temperature is
50 to 60 F. Some interior plants can
withstand night temperatures as low as 40 F for short periods. They should not stay at these temperatures
for long periods though. If they do,
they may deteriorate and even die. A
minimum temperature of 50 F is recommended for many interior plants. The rule of thumb to follow for temperatures
for interior plants is to maintain the night time temperature 10 to 15 F lower
than the daytime temperature.
Remember that plants such as Dieffenbachia
(Dumb Cane) and Agaloenema (Chinese Evergreen) are sensitive to even 50 F. It may cause a limp stem in and foliage spotting in Agaloenema.
The increasing cost of
heating has kept many people from adding plants to their homes and
offices. Certainly where lights are
never on from Friday afternoon until Monday morning and the temperature is
maintained at a minimum creates environments poorly suited for plant
growth. Keep this fact in mind when
assisting your customers in selecting plants for their offices. Only the hardiest of plants will withstand
such conditions.
Water
Incorrect watering is
probably the greatest cause of failure in growing interior plants. The most common question plant growers ask
is, "How often should I water my plants?" There is no easy answer to this
question. Some plants prefer dryer
conditions than others. Temperature and
humidity also affect how often one needs to water plants. Temperature and humidity will vary from day
to day, week to week, and season to season.
A good watering schedule in the spring may be totally inadequate for the
summer, fall or winter. The best answer
to this question, though somewhat vague, is, "Water your plants when they
need it!" Most people water their
plants either by a calendar schedule or when the surface of the soil becomes
dry. Both systems usually result in overwatering. To
adequately water a plant, you must know when to water and how much water to
apply.
When To
Water
Interior plant roots are
usually in the bottom two-thirds of the pot.
Therefore, you should not water until the soil in the bottom two-thirds
of the pot begins to dry. You can't tell
this just by looking. You have to feel
the soil; not on the surface, but about one-third the depth of the pot below
the surface. For a 6-inch pot, stick
your index finger about 1-1/2 to 2 inches into the soil. This is approximately to the second joint of
your finger. If the soil feels damp,
don't water! How damp should it
feel? It should feel about as damp as a
cloth you would wet and ring out prior to wiping a kitchen counter. Keep repeating this test until the soil is
barely moist at the 2-inch depth. NOW,
it is time to water! For larger pots,
the one-third from the surface rule should be followed. For smaller pots, about one inch below the
surface is adequate.
When testing for watering,
pay attention to the soil. If your
finger cannot penetrate 2 inches deep, either the soil is not porous enough or
the plant is becoming root-bound.
How Much Water To Apply
Since most of the roots of
interior plants are in the lower two-thirds of the pot, this is the area you
have to water. The rule to follow is to
water the pot until water runs out of the bottom. How much water should run out? About one-tenth the amount of water you
applied. Watering this way serves two
purposes. First, it guarantees that the
lower two-thirds of the pot was properly watered. Second, it helps to flush out fertilizer
residue (excessive salts).
The pot should not be
permitted to sit in the water that drains into the saucer below. To do so would cause a re-uptake of the
fertilizer residue that should be flushed from the soil. After permitting the pot to drain for an hour
or so, remove all excess water in the drainage saucer.
When a plant becomes very
dry, sometimes the soil will pull away from the sides of the pot. Watering very dry plants requires special
attention. In such a case, you should
water the plant as described above. Wait
a few minutes and remove excess water from the saucer. Re-water the plant. Failure to remove excess water from the
saucer may result in an overflow with the second watering. This second watering allows the water to
penetrate the soil. Sometimes, a third
watering may be required.
Subirrigation
Subirrigation or watering from the bottom is a popular and very
acceptable watering method. It is often
used with African violets. However, continued
subirrigation can
cause a build-up of fertilizer residue into the soil and sometimes onto the
soil surface. This is often seen as a
white, crystalline appearance on the surface of the soil and even the pot
itself. If subirrigation
is to be used, at least once a month, water the plants from the top to flush
out the fertilizer residue.
Watering Pots Without Holes
Pots without holes require
special attention. They should have
longer periods between watering because there is no outlet for excess water to
drain. To know when to water these pots,
check with your index finger as for normal watering and water when the soil
feels dry.
When watering, apply just
enough to wet the soil to the bottom of the container. Don't overdo it! It's hard to get the water out of the bottom
of a pot without holes. Apply a small
amount of water. Wait a few minutes and
check again. If the soil is not damp,
add a little more. Continue doing this
until you reach the proper moisture level.
After a little practice, you will be able to judge how much water to
apply.
Since it is difficult to grow
plants in pots without holes, many people prefer to
double pot. Put the
interior plant into a pot with holes and then set it inside a decorative pot
without holes. Take care to remove the
excess water in the outer pot.
Controlling Humidity
Most homes, offices, and
malls are very dry and are not conducive for good plant growth. Most interior plants do best under high
humidity (60 to 90%). There are several
ways to raise the humidity when it is too low.
One way is to place small gravel in a shallow pan or saucer and fill
with water almost to the top of the gravel.
Place your plants in the gravel-filled saucers. The water will evaporate from the surface of
the gravel, thereby raising the relative humidity around the plants above. When placing the plants on the gravel, be
sure the bottom of the pot is not below the surface of the water. If the plant sits in water, it may become overwatered, lose its roots, and die.
Another way to raise the
humidity around your plants is to group them close together. Since each leaf loses moisture through the
leaf pores (stomata), the moisture lost by one plant helps raise the humidity
around another and vice versa.
Wetting the foliage with a
fine mist of water will also help raise the humidity around your plants. However, the effects on the humidity are very
short and repeated mistings will be required. Take care not to mist the plants late in the
evening as the foliage may stay wet all night and increase the chances of
disease. Over-misting during the day may
also increase the chance of disease.
Misting the plant is the most inefficient methods of raising the
humidity around plants for an extended period of time.
Another alternative to
increasing the humidity is to install a room humidifier. This works well for larger areas. For small areas, the old-time room vaporizer
that mom used when you had a cold or the croup can be used. Just leave off the Vick's salve and set the vaporizer
for cool moisture.
Fertilizing Interior
Plants
The methods
of fertilizing interior plants is quite varied. Some people prefer one of the many slow
release fertilizers currently available.
The "life" of these types of fertilizers may vary from two to
three months to a year and a half, depending on the type selected. The difficulty with these type
of fertilizers is in determining when it should be reapplied. Temperature, frequency of watering, and growing
conditions affect how rapidly these slow-release fertilizers are depleted. For this reason, many fertilize interior
plants with a water-soluble fertilizer such as 20-20-20.
If a water soluble fertilizer
such as 20-20-20 is used, a diluted solution is applied once every two weeks
during the summer and once a month during winter when the plant is less
actively growing. The solution may be
made by mixing one teaspoon of 20-20-20 in each gallon of irrigation water solution.
An alternative fertilizer
program is to use one-fourth teaspoon of the water
soluble fertilizer per gallon of irrigation water
solution. This may be applied at each irrigation.
With either method, make sure that some drains out of the bottom of the
pot. This will help prevent the build-up
of fertilizer residue and possible root injury.
MEDIA, CONTAINERS, AND POTTING
Media
The growing media for growing
interior plants requires careful preparation because the plants must live in
it a long time. Growing media for
interior plants should be porous and have a good water holding capacity. Such media should have approximately 50% air
space. Most of the completely artificial
mixes work exceptionally well. There are
many different types of these mixes on the market. It is often better to purchase a prepared mix
than to mix your own. Purchased mixes
are generally sterile and free of weeds and insects. Mixes you prepare yourself often must be sterilized,
especially if natural soil is one of the components.
When you buy a soil mix,
choose one that is coarse in texture. Do
not purchase a soil mix that has a fine, powder-like texture.
Preparing Artificial Mixes
Most mixes for interior
plants contain a combination of organic matter, such
as peat moss or finely ground pine bark, inorganic
materials, such as coarse
sand, vermiculilte, and/or perlite. More common
mixes used for interior plants are the "so-called" peat-lite mixtures. These
consist of sphagnum peat moss and either vermiculite or perlite. The following are some comments about these
ingredients:
Peat Moss. This component is readily available as bagged
sphagnum peat moss. Materials such as
Vermiculite. This is a sterile, light-weight mica
product. When mica is heated to about
1800 F, it expands, much like popcorn, into a plate-like structure. Vermiculite will hold large quantities of air,
water, and nutrients. Its pH is usually
in the 6.5 to 7.2 range.
Do not overwork vermiculite
when it is wet. This can cause it to
lose its structural properties and nullify the desired effects of using
it. Vermiculite is available in four
sizes. For horticultural mixes, the
coarser textures are desired, usually 2 or
3. The coarser the texture the better, as the coarser materials provide better
soil aeration.
Perlite. This, too, is a
sterile media component which is produced by heating volcanic rock to about
1800 F. The result is a very
light-weight, porous material that is white in color. Its principal value in soil mixtures is
aeration. It does not hold water and
nutrients as well as does vermiculite.
The pH is usually between 7.0 and 7.5.
As perlite
ages, it may produce fluorides which may cause fluoride burn on some foliage
plants. Fluoride damage is usually seen
on the tips of the leaves. The burns
progress from the tip down the leaf.
Fluoride burns can be reduced by adding about 1-1/2 times the
recommended amount of lime when mixing the soil. The calcium in the lime binds the fluoride
into a form that is non-soluble and, therefore, unavailable to the plant.
Pine Bark. Numerous commercial producers are successfully
using a number of mixes that contain pine bark as the source of organic
matter. These mixes, when properly
prepared, have resulted in good root growth with a minimum of root problems. However, as with any mix, they can be overwatered. A soil-
conditioning grade of pine bark is available in most garden centers. The desired particle size is a little larger
than sawdust. The coarse mulch grade of
pine bark is not desirable for use as a potting mix ingredient. A general purpose mix that has proven successful
is a 2:1:1 ratio (volume/volume) of pine bark, spagnum
peat moss, and coarse sand or vermiculite.
Another combination of one-half pine bark and one-half vermiculite has
also proven to be successful. The same
fertilizer additives for the peat-lite mixes can be
used for the bark mixes.
Improving Soil Drainage
Placing one or two inches of
small gravel in the bottom of a pot has been a common practice to improve soil
drainage. This, however, is not the
thing to do. The gravel actually causes
poorer drainage because it shortens the soil column. This can cause excessive moisture to be held
in the soil and cause root problems.
If the soil drainage is poor
enough to need improvement, it is best to use additional additives such as
coarse sand, perlite, peat moss, or vermiculite. Addition of any of these materials will
improve soil porosity and improve drainage.
Suitable Containers
Any type of container can be
used to grow interior plants. But
remember that plastic, metal, ceramic, glazed, or glass containers will prevent
water from evaporating through the sides.
For this reason, many amateur plant growers are more successful with
clay pots. Clay pots are porous and
allow water to evaporate through the sides.
Plants are less likely to be injured from overwatering
when grown in clay pots.
It is permissible to use pots
of materials other than clay. You should
remember, though, you will have to alter watering schedules to compensate for
the reduced evaporation that you will have with them.
Potting and Repotting
There should be a balance
between top growth and container size. A
container that is too small will not hold sufficient water for
a larger plant. Plants in containers
that are too small often wilt rapidly. A
container that is too large will, likewise, dry more slowly. This may keep the soil saturated for too long
a period and lead to root problems.
When potting or repotting a
plant, do not cover the drainage hole with pottery chards or gravel. This only reduces the effective pot
size. If you choose to cover the
drainage hole to prevent the soil from washing from the pot, a piece of screening
material will work well.
Do not press or tamp the soil
too firmly into the pot. This reduces
aeration. Rather, tap the filled pot on
the table or bench to settle the soil and to aid in reducing air pockets. The soil should come to within one-half inch
of the top of the pot. This will provide
sufficient "head room" at the top of the pot to hold water and make
watering much easier.
Water
immediately after potting or repotting. In fact, two waterings would
be beneficial.
This will insure that there are no air pockets in the soil and all the
soil is wet.
TERRARIUMS
A terrarium is a miniature
garden enclosed in a transparent container.
Terrariums are ideal for growing plants under adverse conditions. They produce artificially a more or less
ideal atmosphere for growing numerous plants that could not tolerate the
normally dry atmosphere of the average home.
The enclosure also protects delicate foliage, brittle stems, and leaves
that would be difficult to grow in the open, even if the humidity could be
maintained.
Terrariums are relatively
simple to plant, and once established, they are easy to maintain and will
thrive for long periods with minimum care.
|
Plants
Suitable for Terrariums |
|
|
Dracaena Ivy Small
Palms Peperomia Ferns Sansevieria Hoya Philodendron |
Wandering Jew African Violet Begonia Episcia Pilea Aralia Maranta Cacti |
Materials Needed
Container Potting
soil
Gravel/Perlite Plants
Charcoal Accessories
Tools
Procedures
1.
Select an attractive container.
Wash it thoroughly; polish it so that it will sparkle.
2. Determine where the terrarium will be
displayed. If it is to be viewed from
one side, place larger plants in the background and smaller plants toward the
front.
3. The amount of pea gravel, perlite,
charcoal, and soil mix used varies with the container size.
Rule of thumb:1/4
inch growing medium for every inch of
width
in container. Place a shallow layer of
perlite
or gravel in the bottom of the terrarium
for
drainage. Then sprinkle charcoal over
this
to
sweeten the soil.
4. Soil or a growing medium is necessary in
planting terrariums. Generally, a
packaged mix for house plants is suitable.
When mixing your own soil, use 1/3 soil, 1/3 peat moss, and 1/3 perlite. Cacti and
succulents will require some sand added to the regular mix. Arrange the soil into small hills and
valleys.
5. Select plants which will be compatible as
well as appropriate for the scene which you want to create. Taller plants can be used at the back or to
one side for accents. Work forward to
smaller leaved plants in the front.
6. Remove the plants from the container with
roots intact. Crumble away some of the
soil, but not all. Place the plant in
the terrarium in a pre-dug hole. The
plants should present a desired contrast of shape and color with surrounding
plants. Place variegated foliage next to
solids, and colorful plants next to green plants. An effective arrangement is to have a plant
of major interest near the front and center of the terrarium. Press the soil firmly around the plant to
remove any air gaps. Plants may be
placed in the container and soil added to cover the roots.
7. Watering is not a problem, since plants in a
covered terrarium require only a small amount of moisture. Water at the plant's base,
rather than the entire soil area.
The terrarium is correctly watered when condensation occurs on the glass
within a day or two and evaporates off the glass terrarium; treat as you would
a potted plant. Water when the soil
feels dry to the touch or the plant begins to wilt. Remember:
The soil in a terrarium is usually not as deep as in a potted plant or a
dish garden. It is easier to add slight
amounts of water than to remove any excess moisture.
8. Place the terrarium in a pre-selected spot
which has good lighting, but not direct sunlight. The latter would overheat and kill the
plants. If sufficient natural light is
not available, artificial light can be used.
Plants should receive an average of 12-15 hours of light a day. A 20-40 watt bulb is recommended at a height
of 1 to 2 feet above the top of the terrarium.
9. The plants will survive for long periods
without fertilizing. The objective of
the terrarium should be to keep the plants healthy, but growing slowly, just
short of a starvation diet. If a
terrarium is fertilized frequently, the plants will soon outgrow it.
DIAGNOSING INTERIOR PLANT PROBLEMS
Interior plants have become
very popular in the past few years. Everyone
is becoming more plant conscious and using interior plants more and more in
their homes and offices. Some people
even talk to their plants; however, there is no valid research to support the
thought that they actually talk back.
Plants can, though, communicate to you when something is wrong with
them.
How To
Check For Interior Plant Problems
The following is a list of
things you may do when someone brings you a sick plant. By following these steps, you should be able
to determine the cause of the problem.
Once the problem is identified, you will be better informed when making
corrective recommendations.
First. If at
all possible, knock the plant out of the pot and check the root system. A large number of plant problems are associated
with root problems.
If the roots are white and penetrate
throughout the soil, the root system is most likely not the problem. You would know to check for other possible
causes if the roots appear healthy.
If there are only a few roots and the
plant has been in the container for several months, then a root or media
problem most likely exists. Usually,
root growth is slowed when the media is kept too wet, is poorly drained, or has
insufficient porosity (air space).
If the roots are black and rotting, then
either root rot or a too wet condition exists.
In some cases, roots may have a whitish color and still be poor roots. This can be determined by grasping a root
between the thumb and fingers of each hand and pulling. If the surface pulls away
and leaves only the stele (central root core), then the root is not
functioning. This is caused from
too much water or root rot. If something
is not done soon, the plant could die.
If the roots are wrinkled and twisted
within themselves, the soil probably has too much fertilizer residue (excessive
salts) in it. High salt levels will pull
water from the roots causing them to wilt or shrivel from the loss of water. In severe cases, the roots will be shriveled
completely. This shriveling occurs when
the soil is moist. If the soil is
excessively dry, the shriveling could be caused totally from the lack of water.
In some cases, the tips of the roots may
be brown, yellow, or burned.
Again, high soluble salts may
be the problem. If this is the case,
several thorough waterings with pure water may flush
enough of the salts from the soil to allow the roots to recover.
Second. Ask the owner about the plant. Questions like how often and how much they
water will be clues to solving the plant's problem. Learning the fertilization schedule will
also be helpful. Remember, most people
over-fertilize as well as overwater more often than
they underfertilize and underwater.
Third. Ask
about the humidity. Plants require a
humidity level of 60 to 80%. In most
homes and offices that have central heating and air conditioning, the humidity
runs much lower than that. Symptoms of
insufficient humidity include: drying of
the leaf edges, wilting or drying of the growing tips, and/or a failure to grow
at all. Some plants may even change to a
lighter or pale green color when the air is too dry.
Fourth. Ask
about the light that the plant has been receiving. Plants should not be kept in direct sun. If the newer, fully
expanded leaves are smaller than the older leaves, and if the plant is getting
long and lanky, more than likely the plant is not getting enough light. If the bottom leaves are turning yellow and
dropping from the plant, not enough light is the cause. Watch for sunburn on the leaves, especially
in the early spring. Many times the plants may
have been set out-of-doors while not adjusted to the increased amount of
light. Sunburned leaves have a burned
appearance or a silvery color.
Sunburn can also occur in the winter when
plants are left near windows. The sun is
lower in the sky during the winter months.
Plants inside near windows may not receive direct sun in the summer
because the sun is higher in the sky and the roof overhang shades the
window. In the winter, the sun is lower
in the sky and may actually shine through causing sunburn.
Fifth. Ask the
owner about any spraying he has done, especially to control insects and
diseases. Many chemicals that are recommended
can burn the plant if applied at the wrong rate or if applied when the
temperature is too high. Also, some
pesticides may damage certain plants while safe to use on others.
Remember, too, that many pesticides come
in convenient aerosol sprays. If held
too close to the plant while spraying, these sprays can actually freeze part or
all of a leaf or leaves. Such freezing
will appear as a burn.
Sixth. Check
the underside of the leaves where most insects feed. Because most people only
look at the upper leaf surface and many insects are small and hard to see,
insect problems often go undetected.
Look for light-colored foliage where the insects have sucked the plant
juices. Also, check for malformed leaves
or leaves that have a bronzy color.
These could be caused by aphids or mites.
To detect very small insects, strike the
leaf or branch on a clean sheet of white paper.
Very small insects will appear as specks of dust crawling about. Rub your hand across the paper. If you see red or green streaks, insects are
present and treatment may be called for.
Seventh. Ask
as many questions as possible. The more
you learn about the plant and its environment, the better diagnosis you will be
able to make. More than likely, the
plant owner will tell you what he has done that could cause the problem.
There are many things that can happen to a
plant to cause certain symptoms. The
following information will describe many troublesome symptoms that interior
plants have, along with a list of some of the possible causes of these
symptoms.
If you carefully consider
what treatment the plant has received, you should be able, by elimination, to
determine what is causing the problem.
Once the cause is determined, you will be better able to make a
corrective recommendation.
Disease Prevention
To prevent problems from
occurring with interior plants, check plants regularly. This will head off a serious problem before
it starts. In checking plants, always look
on the underside of leaves. The next
step is to remove the plant from its pot or container and inspect the root
system. Many problems of interior
plants are closely related to root problems.
Proper care, especially
correct watering, is the key to preventing many problems. Many people overwater
their plants. When watering, always
water until the water comes out the bottom of the pot. Then do not water until the soil dries out
approximately 1-1/2 inches below the soil surface. Also, keep water off the foliage especially
in the afternoon. By watering correctly,
many of the major plant problems can be eliminated.
Things To
Recommend
By careful observation and
questioning, you should be able to narrow the cause of the problem down to one
or two possibilities. In some cases,
nothing will help the situation.
However, there are some things you can recommend. While not guaranteed to improve the
condition, they won't hurt. The plant
owner often will feel better if he has something he can do for his ailing
plant. The following are some examples
of what you can recommend:
1. Leach. If you suspect too much fertilizer or a root
problem such as root rot or overwatering, then
leaching can be very beneficial. By
leaching, we mean pouring enough water in the top of the pot or container so
that it runs out the bottom. Wait a few
minutes and do this again. This should
be done four or five times. This washes
the excess soluble salts out of the bottom and in some cases washes some of the
root rot organisms out also. This can't
hurt any plant, and all plants should be leached at least every other month.
2. Provide More Light. Many indoor plant problems occur because the
plant is not growing very strongly. The
plant is more susceptible to problems if it is not receiving enough light to
grow and manufacture its food. Have the
plant owner move the plant to a location where it will receive more light. Plants in dark corners should be rotated
every two weeks with plants that are in bright locations. If impossible to rotate, then provide more
light by artificial means. However, do
not put plants in direct sunlight.
3. Increase Humidity. Most plants are in low-humidity conditions
and increasing the humidity in many cases helps the plant. Increase the humidity by filling the tray or
saucer with gravel and placing the plants on the gravel. The moisture will evaporate up and around the
plants and provide a humidity of 60 to 100 percent, which is ideal. Another method of increasing humidity is to
group plants together and hang some hanging baskets over the grouping. Plants transpire and give off some moisture,
thus increasing the humidity. Misting
also helps increase humidity, but after the mist dries, the humidity is back as
low as it was to start with. If misting
is done, it should be done often enough to maintain a higher humidity for a
longer period of time.
4. Water
Less Often. Most people water their
plants too frequently.
Therefore,
the soil never has a chance to dry out properly. Roots require air to grow and if they stay
wet all the time, they will suffocate and rot.
Remember, every time a plant is watered, it should be watered until
water runs out the bottom of the pot.
Wait until the soil dries out about
5. Repot in a Sterilized Soil and Pot. Although there are no good fungicides that
can be recommended for a root-loss problem, the owner may try the following. Take the plant to a water spigot, wash the
old soil and rotten roots off the plant, and repot the plant in clean, loose,
sterilized soil in a clean, sterilized pot.
The plant has a chance of starting new growth and overcoming the
root-loss problem.
6. Add Extra Lime. Most of the soils used to grow interior
plants have a low pH. Most of the
fertilizers we use on interior plants have an acid base and will eventually
lower the soil pH. Adding extra lime
will not hurt the plant. Even ferns
benefit from the extra lime. Do not
recommend "hydrated lime." Do
recommend dolomitic or agricultural lime. For a 6-inch pot, recommend one
tablespoon. This can be done at least
twice each year. This rate will not harm
most interior plants, unless the water source has a high pH.
7. Spray
Foliage With Magnesium Sulfate. If
the foliage is a light green
or seems to be turning yellow, a
light foliage spray of "epsom salts"
(magnesium
sulfate)
will sometimes green the plant up. This
is not permanent and usually after a couple of weeks, the plant will fade out
again if the problem has not been solved.
This should be applied at the rate of one teaspoon in one gallon of
water and sprayed onto the foliage. If
this low concentration is applied, no burn should occur.
If these recommendations are carried out,
the plant will not necessarily be cured.
These are some things the plant owner can be doing. If they feel they
are doing something for their plant, they are much
happier. In most cases, these
procedures work but don't guarantee them. I hope this will be of help to you in solving
a few of the many interior plant problems you will be faced with.
PROPAGATING INTERIOR PLANTS
You can propagate many of your favorite
interior plants with little difficulty.
There are several ways you can start new plants. You can start some from seeds, but seeds
usually take longer than cuttings. A
plant developed from a cutting will be exactly like the parents in all ways;
its height, flower size, color, fruit and foliage. Cuttings are the only way to propagate many
plants either because they will not set seed, or because the seed they do have
will not produce the same plant.
There are several methods of getting new
plants started. Some of these are tip
cuttings, air-layering, divisions, leaf-stem cuttings, and root cuttings. Some plants can be started by more than one
method.
Tip
Cuttings. This is used for plants
with long stems and leaves along their length.
Cut the stems about four inches from the tip. Some plants that are propagated this way are
begonia, coleus, geranium, hoya, ivy, philodendron, pothos, and most soft-stem foliage plants.
Air Layering.
Foliage plants with thick, fleshy stems (dieffenbachia, schefflera, rubber plant, dracena)
are readily made to root without cutting off the top. If the plant becomes leggy, select a spot
about six inches below the bottom half and make a slanting cut halfway into the
stem. Insert a stick to hold the cut
open. Firm a handful of wet spaghnum moss about the size of a baseball around the cut
and cover completely with aluminum foil or clear plastic. Secure at the top and bottom with plant
ties. After several weeks, when you can
see white roots in the sphagnum, cut off below the roots and pot up; then water. You can cut the remaining long stub of
dieffenbachia or dracaena into 2-inch lengths and bury them in a moist medium
to get more new plants.
Leaf-Stem Cutting.
Certain interior plants (African violet, gloxinia, peperomia) can be started from leaf-stem
cuttings. Just select a medium-mature
leaf and cut it with a 2-inch stem or petiole.
Stick cut leaf-stem in a good rooting medium. When several new leaves develop, transfer
each plant to a pot. If a leaf produces several
plants, separate and pot individually.
Division. Some
interior plants produce more than one plant from the crown (African violet,
fern, aspidistra, nonvining
philodendron). When they become crowded,
it's an easy matter to separate the cluster and pot the individual pieces to
make better specimens. You can cut the
plants apart, or simply pull them apart if the roots are not too
intertwined. Divide so each section has
a good root system. Pot, water, and keep
shaded for a few days.
Other methods would include burying part
of the runners from vines. After they
have rooted, cut off the new plants and pot them. Thick veins of Rex begonia
leaves can be cut in intervals and pegged on a moist rooting medium to take
root.
Rooting Foliage Plants
Do you have some foliage plants that you
would like to propagate so that
you can have several smaller plants to use yourself or
give away? If so, taking cuttings of
these plants is an easy route you can take.
Type Cutting To Take.
The growing tip, whether it is the central leader or a side branch, is
usually the easiest and quickest part of the plant to root. Some plants will root from leaves (example,
African violet and begonia), but most root from a stem. Retain as many leaves on the cutting as possible.
How To Take Cuttings.
When taking cuttings, cut the stem about 4 or 6 inches
long. This is the ideal length
for cuttings. This provides a couple of
inches to be stuck down into the rooting medium and leaves a couple of inches
above to carry on the growth processes.
You may choose to break off the cuttings rather than to cut them with a
knife. If you use a knife or pruning
shears, sterilize between each use to reduce the chance of disease.
When To Take Cuttings.
Most foliage plants root much faster during the spring and early summer
due to increased sunlight and temperature.
Everything seems to grow much better in the spring. However, if you have a plant with a broken
limb and you want to save the plant, take cuttings at that time since by spring
your plant could be dead. Remember that
it takes a little longer during the fall and winter months, and you will
usually have to provide a little extra care.
Rooting Media.
After the cutting is made, place it in a good sterilized rooting medium,
one that will hold enough air and water for root growth. Many rooting media hold enough water, but do
not provide enough air space. Oxygen is
essential in getting plants to root properly.
There are many media that are used.
Many people use sand, but sand is often full of organisms that can harm
the cuttings. Even when sand is
sterilized, it does not provide the proper air-water balance. If you are going to use sand for rooting
plants, make sure that you use a coarse sand and not
the extra-fine sand that is commonly available.
Coarse sand is hard to find, but it is best for rooting and mixing into
the soil mixture. PEAT MOSS is often
used as a rooting medium. It works well
on plants that require a wet medium, but on many of the more succulent plants
it does not work very well. A mixture of
peat and another constituent has a better air-water balance and is usually
better for rooting most plants. If you
use peat moss, make sure it is peat moss and not peat humus. PERLITE is sometimes used, but is better in a
combination with another component. It
is sometimes used under a mist system because it drains very rapidly and does
not hold an excess of water. It is good
to use with peat moss. VERMICULITE has
been found to be one of the best media for rooting cuttings. It holds the proper amount of water and air
but can be easily overwatered. Vermiculite is sterilized, and if kept moist
(not wet), it should provide an excellent rooting environment free of disease
organisms.
Rooting Hormones.
Some people use rooting hormones to speed up root formation. Many of the interior plants that you have are
easy to root and do not require a rooting hormone. However, if you have tried rooting a certain
plant before and had problems, you should probably try one of the rooting
hormones. If you do use a rooting
hormone, make sure that you read the directions and follow them very
carefully. Some common rooting hormones
are "Rootone," "Hormodin,"
and "IBA."
Containers and Depth of Media. Almost any type of clean container can be
used for the rooting of cuttings. The
container should be a minimum of 3 inches deep and may be up to 6 inches deep. The container should be cleaned and sterilized. The best method of doing this is to use one
part household bleach and nine parts of water, i. e.
one pint of bleach and nine pints (1-1/8 gallons) of water . It is best to wash the container well and
then soak it in the bleach mixture for 30 minutes to one hour. After soaking, let the container dry
thoroughly before using. The most widely
used container for rooting cuttings is the flat. Both wood and plastic flats have been used
successfully. Other containers that can
be used are clay and plastic pots, hanging baskets and almost any container that
is clean, sterilized, and of the proper depth.
How Long
Until It Roots. This will vary
according to the plants. Many
soft-stemmed cuttings will root in a few days if given high humidity and warm
temperatures. Roots will form faster if
the rooting media is kept between 75 to 80 F. Some cuttings take three to four weeks, so
don't give up on them.
Check them after the first week and
periodically thereafter. Determining
whether a cutting has formed roots takes a deft touch. Gently tug on the stem of the cutting. If there is no resistance, the likelihood is
that the roots have not formed. When roots form, transplant to a good, loose mixture. You should have good success if you use
vermiculite to root in and then transplant to the potting mixture.
WHAT TO DO WITH OVER GROWN INTERIOR PLANTS
Do you have an interior plant that is
getting too large or out of shape to keep over the winter? Consider pruning it back into a desirable
shape. Pruning should take place before
cold weather sets in so that new growth will fill in and make the plant more
uniform and shapely.
If the plant is large and out of shape,
severe pruning will not always bring it back to its original beauty. If this is the case, it is best to take cuttings
and start new plants which can be controlled and shaped into specimen
plants. After the cuttings are rooted,
plant them in a 3- to 5-inch pot, using a sterilized potting mixture. With good care, in a few months' time, you
will have a plant that is much more desirable than the plant you started
with. Also, you will find that the
smaller plants, besides looking more attractive, will take less space and need
less care. The extra cuttings that you
have rooted can be given away to friends and neighbors as presents or special
gifts or they can be sold. That
overgrown plant still has plenty of use left; don't throw it away yet!
A "MINI - MINI GREENHOUSE" FOR ROOTING
CUTTINGS
Do you have problems getting your plant
cuttings to root? If you do, it could be
that you are not providing enough humidity in the atmosphere around the cuttings. Usually, providing enough humidity is hard to
do unless you have a greenhouse. If you
have this problem, why not fix a "mini-mini greenhouse" for rooting
cuttings? Take a one-gallon, plastic
freezer bag and fill it about one-third (3 or 4 inches) with a rooting medium
(vermiculite works well in the "mini-mini"). Dampen the rooting medium, place the cuttings
in the plastic bag and blow the plastic bag up.
Tie the plastic bag with a twist tie to hold the air inside, and you
will have a "mini-mini greenhouse" to root plant cuttings. With the twist tie in place, the moisture
cannot escape and will collect on the inside of the plastic bag and run back
down into the rooting medium so that you will not have to rewater.
Sometimes, the plastic bag will lose its
air and collapse. When this happens,
remove the twist tie and blow it up again.
When the cuttings start to root, you will be able to see roots through
the plastic bag. When this happens,
remove the cuttings and pot in a good, sterilized potting mix. Try the "mini-mini greenhouse" for
rooting cuttings.
LIGHT AND MOISTURE REQUIREMENTS
FOR SELECTED INDOOR PLANTS
The following list includes most of the
indoor plants that you will be growing.
This list contains information on how large the plant will get at
maturity, which light level is best for good growth, how much you should be
feeding your indoor plants and how much water is required for health
growth. This list gives the scientific
name and in parenthesis, the common name.
Always try to remember a plant by its scientific name, because some
plants have many common names but have only one scientific name.
The following descriptions define terms
used in the following material:
Low:
Minimum light level of 25-foot candles, preferred
level of
75- to 200-foot candles.
Medium:
Minimum of 71- to 100-foot candles, preferred level
of 200-
to 500-foot candles.
High: Minimum
of 200-foot candles, preferred level of 500-
to
1000-foot candles.
Very high:
Minimum of 1000-foot candles, preferred level of
1000-foot
candles.
Dry: Does not need very much water and can
stand low humidity.
Moist: Requires a moderate amount of water
and loves some
humidity
in the atmosphere.
Wet: Usually
requires more water than other plants and must have
high
humidity in its surroundings.
General
rate: One teaspoon soluble house plant
fertilizer per gallon
of water
or follow recommendations on package.
Low: No
application in winter during dormant periods.
Medium: Apply every other month during winter
and every month
during
spring and summer.
High:
Apply every month during winter and twice each month
during
the spring and summer.
Name Mature Light Water
size level Fertility requirements
Aechmea fasciata pot,
basket medium medium moist
(Bromeliad)
Aeschynanthus species pot, basket medium low moist
(Lipstick vine)
Aglaonema commutatum pot plant low medium moist
(Chinese evergreen)
Aglaonema pot plant low medium moist
"Pseudobracteatum"
(Golden Aglaonema)
Aglaonema roebelinii pot
plant low medium moist
(Pewter plant)
Aloe variegata pot
plant very high low dry