CSA-Journal-2016-04

What nutrient actions can I take to
improve blooming, like watering schedule
or nutrient levels, and when should I
take these actions?
Answer: The most important thing to do
to improve blooming of healthy plants, is
to ensure that they receive sufficient light,
especially in spring through early summer.
Remember, sunshine is the greatest and
most consistent nutrient source for your
plants. For sunshine to be used effectively,
plants need to have plenty of water, and
of course the other nutrients you probably
were thinking about when you asked your
question.
For mature plants with a good root
system, they probably need to be given water
every three to seven days from spring
through summer, depending on weather
conditions. During that time, it’s best to
apply a good balanced fertilizer every three
out of four waterings at about half the
strength recommended by the manufacturer.
About once a month in spring it can
be useful to apply Epsom salts (magnesium
sulphate), and an occasional application of
calcium nitrate can also benefit plants.
There have been many, many suggestions
from ‘knowledgeable’ orchidists that
changing fertilizers, shocking the plants,
applying special chemicals, and a host of
other suggestions, will improve blooming.
While some of these may be true, all supporting
evidence is anecdotal. I’ve never
seen a rigorous scientific trial of identical
blooming size plants under different fertilization
regimens published for cymbidiums.
If you give your plants enough light to keep
the leaves to the yellow side of green, keep
them well watered, and keep up a good fertilization
routine, your plants should bloom
well.
There are numerous small spots on the
leaves of one of my cymbidiums. They
appear thinner than the rest of the leaf
Fig. 2 Translucent spots on a cymbidium leaf
because more light shines through these
spots. I don’t see any insects. Can the
source be identified?
Answer: One very valuable tool when
looking for possible insect pests, is a very
strong magnifying glass, or preferably, a
jeweler’s loupe. A jeweler’s loupe isn’t
expensive. Serviceable loupes can be found
for about $10, and they will provide a 10X
magnification of whatever is being viewed.
At higher magnification, it can be quite
surprising what one will see on the leaves or
flowers of a plant. Thrips are barely visible
with the naked eye, and are easily seen and
identified under a loupe. Red spider mite
is not naked eye visible, but again, under
a loupe is easily found and recognized.
Details of the damage on leaves can also
point to a particular pest that may not be
present at the time of viewing.
Circular damage as shown in the
photograph (Fig. 2) is caused by some sort
of sucking insect. The two most common
insects that cause this type of damage
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