The rainy
season is here and it’s a great relief that your plants will be spared from the
hot scorching and drying sun, and the plants will now be freely watered
everyday. However, too much rain can also have a disadvantage, as it can be a
cause by rotting to your valued plants.
Some of the common orchid genera
here in the Philippines includes the
Cattleya, Dendrobium, Vanda, Oncidium, Phalaenopsis,
and the
Spathoglottis.
Each orchid has its own cultural requirement,
and that is why each orchid has a different
cultural tip.
However, some of
these tips can be generalized in a few simple procedures.
On the
onset of the rainy season, orchid hobbyist spray once every two weeks their plants with a dilute fungicide solution,
usually Dithane, which is a synthetic yellow powder mixed in water. It is used as a preventive measure in order
to avoid fungal diseases in establishing into your plants due to very high
humidity. However, for people who do
not want synthetics, the American Orchid
Society recommends powdered cinnamon as an excellent fungicide. Not only does it kill fungal pathogens, but it
is also a safer alternative than synthetic chemicals around children and pets.
Most orchids
are particularly susceptible to black rot fungal diseases from
Pythium and
Phytophthora fungi. These pathogens cause leaves to turn black
before they die. Diseases progress rapidly and can kill plants unless it is treated
with a fungicide in their early stages.
Anthracnose (
Glomerella and
Colletotrichum
spp.) one the other hand, moves from leaf tips to bases, turning leaves brown
as the infection rots tissue. When
Cercospora
leaf spot infects plants, it causes chlorotic leaves, which turn yellow and
bear dark spots that enlarge as the disease worsens.
In addition to spraying fungicides, one has to clean
and remove from your plants dried leaves, dried flowers, flower spikes, and
dried leaf sheaths still clinging to the stem of the plant. These dried plant parts becomes a haven for
fungus and insects once it becomes wet and will start attacking your plants.
If
your orchid is infected with a fungus, you must first remove diseased parts
before you apply fungicides. Apply ground cinnamon to exposed areas where you
removed infected leaves, shoots or roots. You should also treat the surrounding
tissue by first wetting dry areas so that the cinnamon adheres.
It is suggested that mixing cinnamon in oil or
casein-based glue to make a thick paste before applying it over wounds and
surrounding tissues. This holds the cinnamon next to the wounded surface and
creates a waterproof barrier against pathogens.
That also goes true with commercial fungicides, and by mixing it with a
few drops of water to make a fungicide paste.
Fungicide application
is not the only effective recommendation for having a disease-free orchid. In
addition to this, practicing a scrupulous sanitation method when handling
orchids, like washing and sterilizing pruning tools is a good way of preventing
spreading diseases from plant to plant.
Also providing air circulation around plants, which can be
done by spacing plants just sufficient enough so that mild of breeze of air can
pass through them. Another tip is to use
potting media and containers with good drainage. A clogged pot and an orchid soaked in water
for days is a sure way of causing root rotting.
Check the potting medium
for fungus or insect infestation.
Charcoal is the best potting media for aerial orchids here in the
Philippines. For added nutrients, one
may place a thin layer of chopped coconut husk or chopped tree fern roots over
the charcoal, or better still, add a few pellets of controlled orchid
fertilizer.
If there will be
problems with insects, spraying with a recommended insecticide solution is
recommended.
Regular fertilization of
plants, at a frequency of once per week, using dilute orchid foliar fertilizer
is another good way of making your plants healthy and be able to resist
diseases.
If it
is possible to move plants, move plants to an area protected from too much
rain. Or if it is possible to place a
temporary plastic sheet roofing over your orchids, as in the case for
Phalaenopsis and Dendrobiums, it is highly recommended. However, for other orchids like Vandas and
Cattleyas, they are best left there in the rain.
For
more tips on orchid growing, you might
want to visit the Philippine Orchid Society’s Midyear Orchid show which will be held on August
29 to- September 08, 2014 at the Quezon
City Memorial Circle, Diliman, Quezon City.
The theme is “The Great Orchid
& Pet Expo” . Aside from the orchid
show, the event will also have a Pet Show on September 6 to 7, 2014. The area will include an exhibit display, a
trade fair and free lectures.
