Fall
officially arrives this month as do cool nights. If you haven’t noticed yet, the days are also getting shorter
and the sun has moved considerably from its trek North. For Orchid growers, this is the beginning of a time when there is
much to do and enjoy. It is
time to think about where all those newly purchased plants will go when
cold temperatures arrive and time to begin preparing many different
types of Orchids for their blooming season.
With
just a few exceptions, high Nitrogen fertilizers should either be very
dilute or omitted from your fertilizing regimen.
This is a good time to flush media with pure water, i.e. no fertilizers.
An exception might be made for seedlings, but even they need
to be hardened off to protect them from the fungi and bacteria so prevalent
during long, cool winter nights. This is the season to use those other fertilizers
in your cabinet, the ones with the second and third numbers (Phosphorus
and Potassium) higher than the first (Nitrogen). Some growers swear these fertilizers make a
difference, but the most important thing that needs to be done is to
slow growth and allow the bulbs and leaves to mature.
Flushing
is important now as well because the heavy summer watering and fertilizing
may have allowed salts to accumulate.
During winter, watering will be less frequent and media will
be allowed to dry. This process
will concentrate salts on the outside of media if pots and media have
not been well flushed.
Changing
light intensity and direction also needs your attention. Windowsill growers must check to be sure that
plants moved close to the window are not overheating. New leaves often grow up against the glass
and light now striking the glass will burn those nice green leaves. Greenhouse growers may have the same problem
along the glazing. Under-lights
growers should adjust the day length so that plants can begin their
annual maturation process.
Clean
and prepare your wintering area whether it is in a greenhouse, under
lights, or in a window or sunspace.
Clean, weed, and spray surfaces with a 10% Clorox solution to
kill bacteria and fungi that will magically spring to life in the cool
damp weather to come.
Plants
too, need to be prepared for the crowded conditions that come with winter. Check for mealybugs, scale, slugs, etc: You
know the cast of villains to look for by now.
Attend to any pest problems you find now before plants must be
brought inside. Most pesticides
stink for many days after spraying and some are toxic for several weeks
afterward. If you wait too long you may be faced with
a decision of whether to damage your health or the plants. Most scale insects require three treatments
7-10 days apart.
This
summer I visited Grezaffi Orchids, a commercial nursery in Florida that
specializes in Cattleyas, which are notorious for harboring scale. After a day of looking I finally accepted the
fact that this was a scale free greenhouse. I expected the owner to prescribe some very expensive or now illegal
pesticide, but he did not. He
said that the pesticide did not matter, only the time between treatments
using thorough spraying technique.
Joe Grezaffi maintained that the trick was to spray three times
7 days apart, not 8, 9, or 10 days apart, but 7.
He also has a rigorous quarantine and treatment program for new
plants he buys. It is hard to argue with success.
Now
is also the time to study the blooming requirements of your plants because
some require doses of cool weather.
The “Tips Column” next month will cover some of the
major groups and their requirements, but each plant, especially hybrids,
may vary and plants that have consistently not flowered in several years
may be missing some environmental signal. There are many different environmental cues
and learning about what the species or parents of a hybrid require in
nature will provide clues.