The quality of your water is extremely
important for good culture. In nature plants are drenched
by rain water. Rain water results from evaporated water and
unless it is heavily polluted (like acid rain), that water is
very pure.
Rain water is slightly acidic with a PH
factor of 6.4 to 6.8.
Tap water is usually quite acceptable.
Well water is acceptable if its content in
mineral salts is below 120. Hard water (water with
mineral contents above 120 PPM) will create hard deposits on
the leaves of plants. This may clog the pores on the
leaves of plants and reduce perspiration. If your water
is hard it may be beneficial to periodically (once to twice a
year) clean the leaves with distilled water.
Be careful with water that was softened.
There are 2 basic products for softening water: salt and
potassium chloride. Salt adds sodium to the water and,
over the long term, this can be deadly to your plants.
Potassium chloride will not harm the plants.
The best water is water processed through a
reverse osmosis system which will remove most of the minerals
from the water. Our well water has over 1,000 PPM (or TDS - Total Dissolved Solids) of minerals in it (calcium, ...). We soften it
first then we process it with a reverse osmosis (R.O.) system.
The processed water has a mineral content of less than 20
PPM. (Note : if you use an R. O. system then softening the
water with salt is fine because the R. O. process will
eliminate practically all the sodium).
A small home R. O. system producing 30
gallons of water per day costs from $ 150 to $ 300
(Nature’s Way - 800-780-2320). Nature’s Way offered
these systems on sale in September for $ 119 instead of $
142.50 and $ 279 instead of $ 329.00.
I am not familiar with Nature’s Way
system. Our commercial system can produce 1,500 gallons per
day. The processed water is stored in 1,000 gallon tank and
must be pressurized before we are able to use it. I just
mention this to make you aware that you might need something to
storing the water if you consider an R. O. system.
Here are some general rules for potted
plants :
• The potting material should never be
soggy. Water potted plants sufficiently to prevent them from
becoming bone dry.
• In general water once a week, but be
aware that small pots (5” or less) need more frequent
watering than large pots (6” or more).
• Remember that different potting
materials and different size potting materials will dry at
different rates.
• Also remember that clay pots will
evaporate more water than plastic pots and, everything being
equal, will dry faster than plastic pots.
• And remember that clay orchid pots,
because of their openings, will dry out faster than regular
clay pots.
• Conditions are different from room
to room. If you move your plants, observe them to see if
your watering needs adjustment.
• If you place plants in decorative
containers (china pot or decorative basket) to enjoy them while
they are in bloom, keep in mind this will very probably slow
down the evaporation of water and plants will stay wet for a
longer time.
• Finally temperatures, light air
conditioning and heating will affect how fast the potting
material dries out. Be ready to adjust your watering
habits as the season changes, especially from spring to summer
and from fall to winter.
No matter how careful you are when
watering, some water may and will get in between leaves or new
growth. If this water stays there overnight, when temperatures
become cooler, it may promote the growth of bacteria and fungi
that may kill your orchids or the new growth of your orchids.
To reduce risks of this happening you should adopt sound
watering practices.
• Water only on sunny days. If the
weather is cool, cloudy or rainy, you’ll be much better
off waiting a day or two before watering.
• Water early in the day. This
will allow any water that got in between leaves or new growth
to evaporate before nightfall. In our greenhouses we stop
watering at 2 PM in the summer, at 12 noon in the winter and at
1 PM in the spring and fall.
• Water your plants with room
temperature or lukewarm water as a difference of 10 degrees or
more between the temperature of the water and the room
temperature may cause injuries to the plants.
• Water from the top till the water
runs freely through the drainage holes or immerse the plant in
water up to 1/2” or so below the rim and let it absorb
water for 10 minutes or so.
Wipe out any water that splashed on the
leaves or in between the leaves. Using a straw is a
convenient way of focusing the flow of air to blow out water
from in between leaves.
So far we discussed fertilizers, the proper
dosage of fertilizers and proper watering, but giving the
proper fertilizer in the proper dosage is only part of the
issue. We need to make sure the nutrients are made available for the plants to use.
Nutrient availability to plants is affected
by PH levels. See chart on page 15 of “An
introduction to Orchids” published by the South Florida
Orchid Society.
As an example, Phosphorous is practically not available to
plants in the PH range of 7.0 to 8.5. Availability
of the trace element Manganese is mostly available between a PH
level of 4.0 to 5.5. Boron between a level PH of 4.5 to
6.0.
The above mentioned chart (produced by
Michigan State University) shows that most nutrients are
available at their optimal level
between a PH level of 5.0 to 6.0.
An article in the fall 1997 issue of
Greenhouse Grower, although not about orchids, states:
“When the PH of the media is too high, micronutrient
deficiencies can be a problem. If the PH is too low,
micronutrients become more available and can lead to
micronutrients toxicity in some crops.”
Even if we started with water with an
acceptable PH, the PH will change,
up or down, depending on the additives (fertilizer, root solution, ....) we used. So, after we added all additives, we must adjust our PH to a level that will make these nutrients
and other additives available for the plants to use.
Most orchid sources recommend a PH between
5.5 and 6.5 for orchids and that’s what we aim at after adding
nutrients and / or other additives ( i.e. Zerotol,
Protekt,...).
First of course you have to have a way to
measure the PH of the water. This is done with a PH meter
which you immerse into the (well) stirred water containing all
your additives. A PH meter costs from about $ 65 to over $ 100.
Two products are available for PH
adjustment from Growth Products in White Plains, NY
(800-648-7626). PH booster (0-0-25 liquid potassium) raises the
PH while Citric Acid Solution reduces the PH. Go slow ! a
few drops in a gallon can make quite a difference !
The final word about fertilizers is from
Rebecca Tyson Northen in her book Home orchid growing :
“After trying several (fertilizers)
on your own plants, you yourself may come to have a preference
for a certain one. This is good. Is shows that all
is in rapport between you and your plants.”
A Comprehensive Guide to orchid Culture
Venamy Orchids
1460 Route 22
Brewster, New York10509
1460 Route 22
Brewster, New York10509
Toll Free
1-800-362-3612
1-800-362-3612
Fax
(845) 279-2682
(845) 279-2682
venamy@orchidsusa.com
Copyright 2002
Venamy Orchids
Venamy Orchids