Cattleya orchids (and other orchids
such as Brassavola, Miniature Cymbidium, Epidendrum, and Encyclia)
prefer four or more hours of direct east, west, or slightly diffused
south sun. They should dry out completely between watering, then be
thoroughly watered, completely wetting the medium. Their preferred
daytime temperature range is 75 degrees to 95 degrees F days with nights
of 55 degrees to 60 degrees F. A day-night temperature differential of
15-20 degrees aids bud formation.
need very bright but indirect light or 2 to 3 hours of morning sun
(about the same amount of light needed to bloom an African Violet).
Don't allow Phalaenopsis to dry out completely, but water thoroughly
every 4 to 7 days if potted in a bark medium. If potted in Spagnum or a
Peat Moss based mix, less frequent watering is required. Preferred
humidity is 50% to 80%. Preferred temperatures are 70 degrees F daytime
and 62 to 70 degrees F nights. A drop in night temperature of 20 to 30
degrees (but no lower than 45 degrees F) will aid in bud formation.
do well with much the same light and watering requirements as
Phalaenopsis. The major differences lie in the temperature requirements.
Paphs prefer day temperatures between 75 and 85 degrees F. Green-leafed
Paphs prefer night temperatures of 55 to 60 degrees F; mottled-leafed
Paphs prefer night temperatures of 62 to 70 degrees F. We find that they
can be grown in the same environment with just a little attention to
plant placement. Do not allow the potting medium to break down. The
blooms are long lasting and the plants are attractive even when not in
also prefer the same light and watering as Phalaenopsis with humidity
between 50% and 60%. They prefer temperatures not to exceed 80 degrees F
during the day with night 10-20 degrees cooler. Do not allow these to
dry out completely.
and their hybrids prefer the same sun as Cattleyas, and to dry partially
between waterings. Humidity levels of 50% to 60% are preferred, and they
prefer essentially the same temperatures as Cattleyas.
(See our Oncidium Alliance page for more Photos)
ORCHIDS are the largest and most highly
evolved family of flowering plants in the world. They come in many
sizes, shapes, and colors. Some are difficult to grow, while others can
easily flourish on a windowsill. All it takes to grow orchids
successfully is to understand their native environments. Growing orchids
is a pleasure, partly because it can be easy, and partly because some of
the types can be a challenge. The rewards are well worth the effort. The
first step is to know your plant, what it is, and what it needs. Here we
offer some general orchid care advice, followed by more specific
instructions for some of the more popular types.
Most orchids, while native to the tropics, are not
native to the low steamy jungles, but to the cooler elevations from 3000
to 6000 feet. Actual temperature preferences vary from species to
species, but most all orchids will flower best with a drop in night
temperature of at least 10 degrees. Otherwise, it is a general rule
that the orchids will be comfortable with temperatures that you are
comfortable with. As you study orchids in more detail, you will learn
that some types prefer temperatures a little warmer or a little cooler
than others, much like humans do.
Because most orchids grow in climates with moist air,
they do prefer humidity levels between 40% and 60%. Considering
the average house has about 10% humidity, some adjustments will have to
be made. Humidity can be raised by misting leaves every morning, by
running a small humidifier, or, perhaps the easiest method, by setting
the pots on pebble trays. A pebble tray is a container with 5" or higher
sides, larger than the pot, containing 1Ĺ" or more of gravel and
containing water that does not reach the top of the gravel. The bottom
of the pot sits on the gravel but does not come in contact with the
water. Plants themselves raise the humidity and help to purify the air.
You may have noticed that a group of plants often will do better than a
Along with humidity goes good air
circulation. High humidity coupled with stagnant air provides a
breeding ground for fungal problems. Lacking a nice, airy room, a small
fan or a slightly opened window will help.
As far as watering goes, most orchids, though
not all, will prefer a little drying out between watering. Just how dry,
again, depends on the variety. Generally, orchids with thick fleshy
pseudobulbs (stems) and leaves need less water than orchids with thin,
more delicate foliage. It is best to water your orchids in the morning
to allow the foliage to dry before night. Most growers find that orchids
do best when watered thoroughly and then allowed some drying, rather
than giving a little water when they look a little dry. This also helps
to keep mineral salts from building up in the potting medium which could
cause root burn. Most areas have tap water that is suitable for orchids.
If your water supply is generally good for house plants, it will most
likely be fine for orchids.
In the wild, orchids are fertilized only by
minute particles or organic debris that wash over their roots, so
orchids are not heavy feeders. The best advice is to fertilize at half
strength twice monthly. The formulation of plant food you use will
depend on the type of orchid and the type of growing medium it is potted
in. Usually, orchids may be fed during periods of active growth with
20-20-20, or if planted in mixtures containing fir bark, 20-20-20
alternated with 30-10-10.
A general rule of thumb for determining correct
light levels is to judge by the color of the leaves. Reddish or
purplish edges to the leaves are an indication that the leaves are
getting as much light as they can take without burning. Too much light
can also bleach out the chlorophyll, causing the leaves to look pale or
yellowish-green. Too low light makes foliage a dark green and the plant
will not flower well if at all. A healthy orchid in proper light has
foliage that is clear light to medium green with new leaves showing a
soft sheen. Many types of orchids can do very well in a sunny window. If
placed outside (in suitable climates), they will need a little shade.
Leaves can burn in very bright light. Feel of the leaves. If the plant
feels hot it needs some shade or cooling. If you donít have a sunny
window location, additional light can be provided with florescent plant
lights. Some people have found that many of the orchids can be grown
entirely under artificial light, even in a basement. You can grow
orchids almost anywhere if you pay attention to their needs.
Orchids can occasionally "come down with a bug".
Mealy bugs, scales, and aphids can simply be washed off (preferably
outdoors). Malathion has been a commonly used pesticide. Slug and snail
damage can be lessened by not setting pots directly on the ground when
putting orchids outside for the summer. A product containing
metaldehyde is commonly used to kill slugs and snails. We cannot
make specific recommendations to you for pesticide use. However, if you
do use a pesticide, please follow the instructions.
Most orchids will need to be repotted at one time or
another, either when they outgrow the existing container or when the
potting medium begins to break down, generally every 2 to 3 years. Many
orchid plants have roots that like to wander out of their pots. This is
normal and in itself is not a sign for repotting need. Because orchids
like impeccable drainage, potting materials such as fir bark,
osmunda fiber, volcanic rock, and charcoal have all been used. Exactly
what mixture should be used and when to repot will depend on the orchid
variety, your climate, and the size and age of the plant. We have very
good success with a mixture containing very coarse peat moss. This works
well for us with a variety of orchid types. It not only works well in
the greenhouse, but in the home as well. Few orchids will live in what
would be called "potting soil" so this must not be used.