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Nancy G. · 16-09-2006, 04:09 PM posted to rec.gardens.orchids

wrote:
The Oncidium has two flower spikes. I can't tell if it's a single
plant with two spikes or more than one plant. The planting medium
appears to be some kind of moss - no soil.

On an oncidium, most commercial growers will use sphagnum moss. It is
not particularly well suited for oncidiums in the home environment.
Most new growers have a tendancy to overwater. The moss stays wet
around the roots and causes rot. With the exception of some
teresstrial orchids, regular potting soil should NEVER be used. After
the blooms fade, you should repot into a looser orchid mix. This will
allow the media to drain and give more air around the roots.

It's in a clay pot.

If there is no plastic pot inside the clay and the clay is unglazed,
this will help to offset the wetness of the moss because the clay pot
is porous and will help it dry faster

It's in the same place as the Phal. I water it when it feels dry with
Orchid food - same as I did with the Phal.

In the future it will need brighter light than the phal. BTW, if you
can get a night time temperature drop down into the 50's for your phal
it will help initiate the spikes for its seasonal bloom. It's a good
time of year to leave the window open or take the plant outside for a
couple of weeks. Don't let it get too much sun or down below 50F.

One spike is flowering beautifully. The other has many buds but has
not flowered. I noticed the buds were covered with black specs.
Almost like very small poppy seeds. I wiped the all off with a damp
cloth. The other spike is not affected.

Did the black spots appear after you brought the plant home? Did they
move? When you buy plants from retail stores, the plants may have an
infestation of insects. There are a lot of plants, some exposed to the
outside, a lot of handling, and crowding, etc. I usually recommend a
quarantine or isolating the plant for observation to avoid migration of
a pest to other plants in the house.

What are these? What should I do?
For right now, enjoy the blooms and observe the spots. If they return
it may indicate an active infestation. Sometimes, it is "nothing" fly
spots (excrement) from flies or spiders attracted to the nectar or
sweet stickiness of the buds. Look at your phal carefully, too.
Because you put your oncidium in the same place it may be the source
and you missed it because it was out of bloom.

It will probably need to be sprayed for insects in the future anyway.
When you spray, use an insecticide for plants. Delivery should be via
pump or spritzer bottle. Do not use an aersol or spray can.
Thanks

Best wished, and happy growing.

Nancy