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Old 04-11-2006, 07:29 PM posted to rec.gardens.orchids
Kenni Judd Kenni Judd is offline
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First recorded activity by GardenBanter: Jul 2006
Posts: 158
Default Advice for deflasking Vanda seedlings

Watch carefully for signs of (a) contamination or (b) a slowing of growth
(indicating that the nutrients in the agar are used up), but unless and
until you see one of those, I wouldn't rush to get them out of the flask.
Spring would be a better time.

When you do take them out, separate them as gently as possible to avoid
breaking roots, and don't worry about removing all the agar. It will rinse
away on its own during the first few waterings, but we have found that it
tends to cushion the transition from bottle to real world environment, while
it lasts.

At that size, I don't think I would compot them; it would lead to a lot of
root breakage when you take apart the compot. I would give them individual
2" pots. Here, it would be net pots with a little coco fiber, but your
humidity is a bit lower than ours and you may not want to water as
frequently (our vandas are watered daily in hot weather, every other day in
the temps you describe), so you might want to use clay pots and a little
"wetter" mix. Coconut fiber dries quickly. In your conditions, I think I
would go with the 2" clay pots and the mix that we use for very small catt
seedlings (OFE seedling mix cut 50/50 with extra-fine charcoal -- OFE
seedling mix, by my eyeball, contains about 60% very fine fir bark, 30% fine
treefern, and 10% extra-fine charcoal, in case you have to mix the whole
recipe yourself). Start them out very low light and increase the light
gradually once you see new roots or leaves growing after the transplant.

We do not treat deflasked seedlings with any kind of fungicide, although it
is commonly recommended. In your situation, I would spray the plants
lightly with a root stimulator such as Superthrive or K-L-N, soon after
potting them up.

You will probably receive many opinions, please pay more attention to those
from people with conditions more similar to yours, and/or more experience
with deflasking vandas, than mine. We've done very few vanda flasks,
preferring generally to import those at "near-flowering-size."

Survival ratios are very iffy figures, because there are so many
variables -- starting with the quality of the plants in the flask, then
everyone uses different methods -- "perfected," or at least improved, by
years of trial and error G. My first few flasks yielded only about 50%
survivors; fifteen years later we're up around 85-90% (on hand-selected
flasks, which restricts the range of the first and most critical variable).

Best of luck, hope this helps, Kenni

"Steve Weaver" wrote in message
ups.com...
I just bought my first flask. It contains around fifteen seedlings,
each approximately 1.5 to 2 inches tall and wide, of Vanda bensonii.
Although this is a bit intimidating since it will be a new experience
for me, it's also very exciting. Now I just want to make sure that I do
whatever's in my power to help the seedlings start off on the right
track. They'll be growing indoors over the winter, where there are lots
of east and south facing windows; the temperature range fluctuates
between a high of 72 degrees F during the day, and a low of 65 degrees
F during the night. The humidity level during the winter hovers between
a high of 63% and a low of around 53% (the lower humidity level usually
is experienced at night, but I do have a couple of room humidifiers on
each floor of my house that keep the humidity from ever dropping below
the 53% value). I also have an RO unit so that the orchids are provided
with good quality water. Can anyone give me some advice regarding
whether or not the seedlings should do well in this environment,
whether they should be placed in a compot or potted individually, and
what kind of potting medium they will most likely respond best to. And
finally, if you have any direct experience with this species or Vanda
species in general that are just out of flask, can you let me know what
you would consider to be the average mortality rate for seedlings of
this size. I know and accept that there will be casualties, but since
this is my first experience with deflasked seedlings, I'd like to have
a general idea of what is considered an acceptable (as opposed to
ideal) die-off rate. Thank you in advance for your help.