The Paphiopedilum Grower’s Manual
© Lance A. Birk - 2004-2006 - All Rights Reserved
CHAPTER 7
Not
everyone has the desire, or the capability, to grow his Paphiopedilum orchids in a greenhouse. Apartment dwellers have no room for a greenhouse and people
who live on small parcels of land seldom have adequate space for theirs. Many people do not have the extra money
to spend to build one, while others just do not care to become involved with
the upkeep of a greenhouse. And
newcomers to the hobby seldom have a greenhouse ready to house their orchids,
but they all somehow manage to find ways to grow their paphiopedilums anyway.
As
a matter of fact, there are many thousands of people who grow only a few
orchids in their homes, and they do so very successfully. Depending upon individual
circumstances, some people find space for growing near a window using natural
light, while others who have no windows at all use artificial lights. On the whole, paphiopedilums can be
happy growing in the same conditions we humans like, with the exception of the
need for more humidity. And unlike
growing plants inside a greenhouse, a home has few temperature extremes or
insect pests to worry about.
Homes
with many windows are ideal because those species with different light
requirements can be placed where their needs will more easily be met. In homes with few windows, or in rooms
with poor light, these orchids can be grown very successfully under special
growing lights. If you have a
large collection of Paphiopedilum
orchids, you can also grow them in a spare room, or in the basement using these
same lights. By using a little
ingenuity one can think of many ways to moisture‑proof the rest of the
house, or a windowsill or closet so that neither the irrigation water nor the
humidity will cause damage.
When
plants are grown under lights in the home, certain problems exist such as:
excess heat, lack of humidity, loss of blooms or weak growths, but these are
things which can be remedied. If
you intend to raise your Paphiopedilum orchids in your home, or if you do so already, the following pages
should help you to provide a suitable environment needed to keep your plants
happy and productive.
There
is one caution however, which must be made very clear. NEVER use inside tap water to
irrigate your orchid plants if your residence is equipped with SOFTENED WATER. In most circumstances, softened water
is made through an ion exchange process using sodium to replace calcium in the
water. The substance used is, as
most everyone will recall, is salt.
It is just ordinary table salt.
Salt is sodium chloride.
Salt kills plants! Therefore,
you must use water from a source which is not softened. In some homes, only the hot water is
softened, so it is safe to use tap water from the cold faucet. Make certain it is the case before you
use inside tap water, or else provide your plants with water from a source
outside your home. This is
necessary for all plants in your home.
A
windowsill can provide an excellent place to grow your paphiopedilums, but you
must take care to see that your plants do not get either too hot, too cold, or
become sunburned. Windows with a
southern exposure are usually best for growing any kind of plant, and
paphiopedilums are no exception.
In many locations however, and particularly when days are long and warm,
you will need to provide some protection from the burning rays of
sunlight.
A
thin glass curtain, or a single layer of cheesecloth can be placed between the
plants and the window glass to block those direct rays. Filtered light is desired, with enough
brightness to satisfy the plant’s needs without being so intense that it
causes heat to build up within the tissues of the leaves thereby injuring them.
Certain
species such as Paphiopedilum philippinense need very bright light in order to set blooms, and if
some means are devised to circulate the air directly surrounding the plant, it
may be possible to omit the shading material. You would have to experiment with this idea very carefully,
since any plant placed in the sun’s rays could be damaged by the
excessive heat that builds up very quickly, especially if it is one which has
been maintained in a darker place.
By
far, the large majority of Paphiopedilum species and hybrids can be grown in windows with either an east or a
west exposure. There are times
during parts of the day, or during certain times of the year when light
intensity will have to be checked, and perhaps filtered because of the
differences in the angles of the sun's rays. A regular monitoring of these conditions should be part of
your normal routine.
Air
movement within the room can make a difference in the amount of light your
plants are able to receive, so you will need to observe the extent and the
amount of airflow when calculating their light requirements. You should also examine the leaves of
your plants to see their condition and color. (Plants which seldom flower, and have floppy, dark green
leaves need more light.)
Yellow
leaves with sunburned spots are in too much light, and probably could use a bit
more fertilizer, as well as more shade and air movement. Those plants with upright, bright green
foliage and which produce flowers on a regular basis are doing just right. You will not need to change their location
or your treatment of them.
One
of the main challenges encountered when growing orchids in the home is the fact
that it is sometimes difficult to bring them into flower. This will be demonstrated by those
plants which have fewer flowers, and by those which bloom irregularly or
infrequently. Because
paphiopedilums usually have low light requirements, this is not a normal
problem with the genus, but you will need to know how to realize normal flower
production when you grow your paphiopedilums in your home.
If
you do not have a window with sufficient light to grow your plants in a sturdy
and thrifty manner, you can supplement their light requirements with the use of
artificial lighting. Many light
bulb manufacturers produce special lights, especially made for indoor plants. These growing lights provide the
correct spectrum of light needed by plants, and they can be used to augment a
limited natural source.
By
varying the total number of hours, the intensity of light or both, you can
provide sufficient quantities of light to fill your plants' needs. These lights can be strategically
placed above those plants in a windowsill in such a manner as to not interfere
with natural light that falls upon them.
They can also be placed where they will not be too noticeable.
During
the winter months, heat escapes rapidly through a closed window and much of the
heat will be drawn from your plants if you do not take measures to prevent
it. In very cold climates, double‑paned
glass is used for insulation, but even this may not always prevent your plants
from becoming too cold. At such
times when outside temperatures drop considerably, you might want to grow your
windowsill orchids on a moveable cart, which can be moved away from the colder
window area. If this is not
practical, small electric heating pads or coils can be used to maintain
sufficient heat.
Especially
for those plants growing in a room where you do not "live", you
should watch to see that when you are absent from the room, they are not
exposed to excessive cold. An
equal danger, during periods of cold, is a heater vent or fan which blows directly
upon the plants. This extra heat
could cause excessive dryness that will be noticed by the decline in your
plants’ turgidity or robustness.
Something
less noticeable is the fact that the excess heat may not be enough to cause
desiccation, but it might be keeping the night temperatures too high, thereby
preventing a plant from becoming chilled sufficiently to set buds. You would probably blame it on the lack
of light unless you placed a registering thermometer by your plants to record
its specific temperature ranges.
There
are many Paphiopedilum species
which can be grown just about anywhere in rooms that receive sufficient amounts
of light for you to grow them well, and for them to flower profusely. Plants do not always have to be grown
directly next to the windowpane.
Through experimentation, or from the experiences of your other
orchid-growing friends, you will learn more about where to place certain
plants.
In
your own home, you might choose one particular room which can be used for
growing your plants, and then when they are in bloom you can take them into the
living room or dining room, or wherever you wish to enjoy their flowers. After they have finished blooming they
can be returned to the growing room.
Regardless
of where in your home you grow your plants, you will need to supplement the
humidity in order to provide a suitable growing environment. Interestingly, plants grown in the home
seem to require less humidity than those that are grown in a greenhouse. Perhaps it is because there is a
smaller range of temperature variations, or possibly there is less heat that
can cause the humidity to drop during the middle of the day. It may also be because they receive
less light. Whatever the reason,
it works to our advantage, because if we had to maintain the same humidity as
in the greenhouse, the house might be damaged.
You
can increase the humidity directly around them by placing your plants on a tray
filled with gravel and then partially filling it with water. As long as the water level never
touches the bottoms of the pots, your plants will appreciate this humidity. If the water level is kept too high and
the bottom of the pot stands in water, not only will the roots rot, but also
the water will be drawn into the pot through osmosis and the mix will soon turn
sour. Your plants will suffer from
this treatment.
Aluminum
bakery trays are suitable for a small number of plants, but if you have many
plants in your collection you will want to use a large galvanized steel or
plastic tray, made to contain both the gravel and water. A larger tray is easier to work with
because it will provide sufficient room for you to move your plants around on
it more freely, and it also can appear more attractive. Properly constructed, a tray should be
deep enough to hold any run‑off water from your plants after they have
been watered, and it should have a drain so it can be emptied as needed.
Because
of the extra humidity provided by such an arrangement, you will need to protect
the surrounding walls, the floor and ceiling from any water damage. Perhaps plastic sheeting placed under
the tray, and a layer of it covering the walls will suffice, but you may also
find the need to use a special type of sealer to paint those surfaces.
It
will not hurt your plants if the humidity fluctuates during the day; in fact it
will harden their growths, which is something you will want to happen. If you experience a continual problem
with trying to maintain adequate humidity, you can use a mist sprayer several
times during the day, to mist your plants. If the plants are properly potted in a porous medium this
will not harm them. You should see
that when you mist frequently, if water from the leaves runs into the pot, it
can drain freely and that it is not so much so as to cause the soil to
decompose prematurely.
Another
and more simple means of maintaining humidity is to grow a large number of
plants. After irrigation, each
plant supplies the others with humidity as it respires, and as the pots dry
out. This is one of the best ways
to keep the humidity at a suitable level.
Do not crowd too many plants together to do this, as it can restrict
their air circulation and cause your plants to experience problems with rotting
or from insufficient light.
There
can be no set schedule for watering your houseplants. You will have to examine each plant and to judge for
yourself when it is their time. With
experience will come the ability to learn this, and you will be able to water
your plants according to their individual needs. Trying to water all your plants on a certain day will only
cause problems and maybe even the loss of some plants. They are not intelligent, and no matter
how you try to explain it to them, they will surely refuse to accommodate your
artificial schedule. It only takes
a few minutes from your day to accommodate their needs, so be understanding. Your healthy plants will reward your
patience.
It
does happen at times however, that when your plants are well potted and in the
same types of pots and potting soil, you
might find that nearly all of them will need watering at about the same
time. You may be able to set one
or two particular days each week to irrigate them, and will find that they will
respond favorably.
When
you water your plants, it is a good idea to take each one to the sink and run unsoftened
water through the potting soil several times. Let them drain off before returning them to their growing
areas, so the tray underneath the plants does not become overfilled with
water. If this is too difficult a
job to be handled each time they need watering, perhaps it can be done at least
once a month. They will need this
thorough watering on a regular basis, in order to leach the soil and to keep
salts from building up to a toxic level.
(Remember…UNSOFTENED water.)
If
you pay careful attention to your Paphiopedilum plants, and use a source of unsoftened water, you
might be able to calculate their irrigations so that most of their water
requirements can be supplied by misting them. The misting would need to be carefully applied so as to
prevent more than just a small amount of it from actually draining into the pot
itself.
A
denser potting soil might be needed if you use this practice, one which will
retain moisture for longer periods of time. Careful attention must also be paid to monitor how the
plants are responding and remember too, to keep the potting mix always moist, but
never wet. Paphiopedilums do not
like continuously wet roots.
Your
plants will tell you how they are doing if you pay attention to them. Yellowing leaves can be a sign of
excess sunlight, but it can also be from too much water. Paphiopedilums are low-feeders, they do
not require much fertilizer, and a lack of nitrogen would not usually be
suspected as a main cause. Smaller
new growths might be from too little water, or from too much water, and a limp
or shriveled plant will tell you that it is not receiving sufficient
water. You will need to determine
if this is because the roots have been damaged.
By
‘listening’ to your plants, and by studying their signals, you will
be able to tell both when they are not well, and the differences between each
of these problems. Experience is
the best teacher since almost every plant is different. If you are observant, in time you will
learn to identify an unhealthy plant and how to modify its treatment, and to
properly meet their needs. It is
not difficult; it just takes some time to learn.
A
good thing about growing plants in the home is that there are seldom any
temperature extremes like there are in a greenhouse. In the home the heat builds up gradually during the day,
then it slowly drops during the evening.
But in the greenhouse, as soon as the sun reaches the glass the
temperature goes up. Then, when
the cooler clicks on, the temperature will drop rapidly. The temperature range will be
maintained at a ten to fifteen-degree differential.
In
the home, if unfiltered sunlight reaches the leaves of your plants, their
internal temperature will rise quickly, and can cause sunburn. However when sunlight enters the home
through the windows, the actual raise in temperature throughout the house will occur
much more slowly, and it may take several hours for it to go up just a few
degrees. The reverse occurs
somewhat quicker at the end of the day.
Paphiopedilum orchids are usually happy with the same temperatures
in which we are comfortable.
Actually, they generally do best with a temperature at night of 55°
to 60°. During the daytime
they do well with the same temperatures we like.
If
temperatures in your home are higher than this, perhaps you might place your
plants in a separate room, away from your living area, in order to give them
the lower temperatures that they usually need. Possibly you might be able to adjust their proximity to a
window where it is cooler, to provide this same effect.
During
hot weather, if the internal temperature of the house rises too high, you will
find that misting your plants will help to lower their temperature, as well as
helping to keep them from desiccating.
You will want to check the moisture content in their potting soil, to
see that they have not dried out suddenly, or that perhaps they might have
become waterlogged by excessive misting.
Added air circulation will help to cool your plants through increased
evaporation, but they will need to be watched for excessive drying during these
times.
If
you have an air-conditioned house, you will want to watch your plants closely,
since air conditioning often removes most of the excess moisture in the
home. Unless your air conditioner
is fitted with a humidifier, it is surprising how quickly your plants will dry
out when the air conditioner comes on.
Again, by misting and watching the water level in the plant trays, it
will help you to maintain the required levels of humidity and temperatures.
Several
different kinds of growing lights are now made to supplement natural
sunlight. Essentially, they have
been made to achieve nearly the same results as would be found outside. There are kinds with ‘High Output’,
or ‘Very High Output’ ratings, which can be successfully used for
growing large numbers of plants in a windowless room.
In
the past, it was thought that a combination of both incandescent and
fluorescent lights would produce a spectrum of light suitable for plants, but
now this combination is seldom used.
Aside from the need for fewer fixtures, there is the added benefit of
having much less of a heat buildup, which sometimes proves to be a formidable
problem when either incandescent or fluorescent lights are used.
The
new plant lights are fluorescent tubes; each one covers a much larger area than
an incandescent bulb. In
restricted spaces there might be a problem with heat buildup, generated by the
fluorescent fixture ballasts, but if it becomes extreme, the ballasts can
always be moved to another room where their heat can dissipate better. In some places this heat can be
utilized to heat a cold room instead of using a heater, but you can only make
this determination if you try the arrangement in your own growing space.
If
the windows in your home do not provide quite enough light for your plants, you
can supplement their needs with a small fluorescent plant light. Depending upon the size of the window,
the numbers of the plants and the amount of light needed, you may find that the
additional light may only be needed during parts of the year.
In
particularly dark locations, a plant light might also be used to supplement the
total number of hours the plant receives light during the day. If you do use artificial light to
increase the day length for your plants, remember that it should come on an
hour and a half before sundown, since you will want to keep them in their
daytime cycle, uninterrupted. A
maximum of sixteen hours can still give them time to rest during darkness, but
a twelve to fourteen hour day is preferred. (Paphiopedilum delenatii is one species which seems to require a day length of
about 12 hours to set buds.)
Many
homes have basement areas which make a suitable location for growing large
numbers of orchids. Paphiopedilum orchids do well under this arrangement because of
their general lower light requirements.
However a basement is not without problems. In a basement there is always the possibility of water from
the outside leaking in through the walls, (causing problems with excessive
humidity) or cracks in the walls or floor. Then, even if your basement walls and floor are perfectly
sealed, there can be problems with how to rid the room of excess irrigation
water, and also how to keep the excess humidity from the rest of the house.
Most
basements are constructed to withstand the effects of ground water, but it
still is a good idea to paint the walls and ceiling with a water-sealing paint,
just to be sure that there is no leakage.
The paint should be white, to reflect as much of the artificial light as
is possible, which may even enable you to minimize the number of light fixtures
needed.
For
whatever method you choose, benches used for basement growing can be made of
almost anything. There are
commercially available greenhouse benches, or you might make your own. Even old tables can be used to hold the
plant trays on which you grow your plants. Pipe frames are both popular and long lasting, and their
cost is reasonable. But before you
decide which to use, it would be a good idea to see what others in your area
are using before you make that final decision
You will want to install your reflective lighting fixtures on small
chains and hang them from the ceiling.
They can then be raised and lowered to accommodate the different types
of plants you will be growing.
Some of your multi‑flowered types have flower spikes which can be
several feet tall.
Homes with the heater installed in the basement might provide all the
heat necessary for your orchid collection. An electric heater is good, in view of its absence of
exhaust gases, but other types can also work. If you have a gas, oil or coal burning heater, you must be
certain that the flame burns cleanly, since improper combustion can cause
flower buds to blast, and it can even cause damage to your plants. This test can only be performed by a
technician, and it is a necessary requirement.
If
the heater makes the basement area too warm at night for your Paphiopedilum orchids to set blooms, you might find that reversing
their light schedule can solve the problem. Setting the artificial lights to shine at night when the
basement temperatures are warmer, and then reversing the daytime schedule might
solve this problem. Each situation
will need to be determined individually.
You
will need fans to circulate the air in the basement growing area, and they can
be placed where they can effectively move the air. You will want to check the air currents and temperatures in
several different locations to see that your fans are doing a proper job of
moving the air. In warmer weather
you may experience a problem with excess heat, but this can be controlled to a
degree, with the use of extra fans.
If there are doors or windows which can be opened, they too can be used
to regulate cooling.
In
the absence of windows, you can direct the fans to blow the heated air up, into
the rest of the house, but this may not a good solution since it is so
humid. Instead, an alternate idea
would be to install an exhaust shaft to the outside, with a
thermostat-controlled fan and a pressure operated, louvered shutter. This system could be constructed to
operate automatically.
The
general rules of culture for plants growing in your basement are the same as
for those grown in the other parts of the house, and it is essentially the same
as for plants grown inside a greenhouse.
You should water them when they need it, and fertilize them weakly, on a
regular basis. Watch for pests,
since once some types gain a foothold in your home, it can become a very
difficult trying to eliminate them.
Watch especially for rots and bacterial diseases, because of the
inherent problems caused by the lack of sufficient air circulation. Since they often and suddenly make
their appearances known, you must act quickly to treat these problem areas.
When
you obtain greenhouse-grown plants you will find that they have a fairly long
adjustment period to become acclimated to growing under your growing
lights. This shock will be noticed
by a reduction, or possibly a halt in their growth rate, during which times you
must be careful not to overwater them.
Individual plants respond differently, but it happens in most cases. Sometimes it might take a year for the
plants to adapt.
On
the other hand, plants grown in poor natural light conditions have responded
favorably when brought into a good, strong artificial light situation. And one of the advantages of growing
your plants under artificial lights is that you are able to alter the day
length of your growing area to compensate for that reduced amount of their
previous light condition.
Although
it may take time for you to find the best situation for your plants,
paphiopedilums are well adapted to culture inside the home. A bit of experimentation will be
rewarded when you find that spot that fits their needs.
Just
because your plants are grown in the home, it does not have to mean that they
are less healthy than those grown in sunlight. Artificial light of the proper spectrum can produce plants,
which even an expert will find hard to distinguish from plants grown inside a
greenhouse.
One
of the best rewards for growing your plants in the home is that they are right
there with you. There is no need
to go outside into the snow, or to bring muddy feet into the house; they are
just in the other room. And since
they are right at your fingertips, they usually receive more attention than
those grown in a greenhouse. Of
course, this close proximity can also aggravate your problem with
impatience…waiting for those flowers to open and all. But you can learn to deal with it. …….Right?