Winter Wrap Up
The winter of 2013 was particularly difficult for growing Stanhopea. In January the temperature dipped to 31°F (-0.6°C) for only the second time since I have lived in San Diego. This low temperature duration was only for a few hours on one night, but it was unusual in that is was part of a 10 night period in which temperatures ranged from 35-39°F (1.7-3.9°C). This long cold period was particularly difficult for several of the Stanhopea. Some orchids exhibited bacterial growth presenting a few days after the cold snap along with a loss of few leaves after several weeks. In addition to this cold, a very intense hail storm occurred one night and caught me off guard. Most of my Stanhopea collection is sheltered by trees, roof overhangs, and plastic saran; however, a few plants were partially unprotected during this storm and took some damage. If I continue to have these tough winters, it will give me incentive to complete the building of a cool greenhouse to protect the orchid collection better by next year.
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| Stanhopea shuttleworthii growing underneath a tree canopy. The plant looks good from a distance (left). However the hail storm damaged the right side of the leaf causing pitting and the cold weather cause bacterial spotting (right) |
Stanhopea Spring Culture Checklist
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Begin watering these species regularly when new
growth begins (S. hernandezii, S. insignis, S. jenischiana, S. lietzei,
S. maculosa, and S.martiana).
·
Begin fertilizing all species regularly once new
growth begins. I often reduce the
manufacturer’s recommendations in half and fertilize every week or what is
known as weakly-weekly. Stanhopea can be rather heavy feeders
when they are in active growth.
·
Weed baskets to prevent ferns and other plants
from taking up space in baskets.
·
If you grow Stanhopea
in a sunny area or a greenhouse that receives strong sunlight you may want to
place saran shade cloth over the growing area in early spring before the
sunlight becomes too strong for them.
You may also want to consider moving the Stanhopea to another shadier growing area.
·
Use of methaldihide products is advised on a
weekly basis at this time to prevent slugs from disfiguring new growth and
impacting new inflorescence and bud growth.
I often use a product called “That’s It” that is a granular form and
therefore leaves less residue in the growing media. I am currently testing some more organic
methods of slug control.
·
In mid to late spring make sure to check for
growing inflorescences and ensure that their growth is unimpeded by other
plants or the basket. If need be place a
plastic label underneath the inflorescence to help direct the growth out of the
basket.
·
Spring is the second best time to re-pot or
re-basket Stanhopea, I think late
fall is actually the best time because most Stanhopea
have already bloomed and are in a rest period.
It is recommended that you allow new growth to begin before you
re-basket so that the growth can mature somewhat before you transplant the
orchid. This will prevent the new growth
from being impacted during the process.
Early spring is a good time to transplant because it will also prevent
damage to most nascent inflorescences.
·
Keep a careful eye out for spider mites as the
spring continues and our weather begins to warm and dry out. Small yellow spots on the foliage signal that
these pests are active on your Stanhopea. Spray infected areas with an insecticidal
soap to kill the pests as soon as possible to prevent them from damaging the
plant further and spreading to other orchids.
·
You should also be diligent in keeping watch for
fungus infections at this time on leaves.
Several fungus attack leaves when humidity is high and temperatures are
warm. Black or brown spots of leaves and yellowing of leaves in odd patterns
are usually the cause of fungus or bacterial infection. Treat with a fungicide or bactericide. I often use Physan 20 to deal with the
problems and prevent further damage to the plants.
