Re: Bletilla striata

Judy wrote:

>I have 7 Bletilla striata seedpods hanging on now & they are red on one
>side & green underneath.  What color will they be when they are ripe
>enough to harvest & try to grow? 

Generally the rich green shade starts to take on slightly olive tones
once the pod has swollen fully.  At this point splitting starts to
take place and the minute, dust like seeds are released.  The pods
need watching carefully and daily inspection is recommended.  Once the
splits become apparent, carefully cut the pods from the stem and place
in a paper bag/envelope prior to sowing.

> Also, I had someone tell me how to
>germinate them in regular potting soil but I lost the letter.  Would
>appreciate the directions again & thanks so much.

I find it almost inconceivable that they could be germinated in a
standard potting compost since the seedlings are so sensitive in their
early stages that the slightest hint of artificial fertiliser is
likely to burn the initial root growth (usually no more than a few
tiny hairs for the first few months)  if it does not prevent
germination in the first place.  The ideal medium is live, growing
sphagnum moss heads with 1"- 2"  long stems that are bunched fairly
tightly together over a substrate of moss peat (not the black, gritty,
sedge peat).  If live moss heads aren't available, true moss peat (in
this case, substitutes such as coir will not work at all well) and
washed perlite  75%:25%, together with a little, finely powdered
charcoal will work almost as well.

Pots of this are stood in trays or saucers so that any watering (rain
water or at the least boiled and cooled tap water) can take place from
below.  Seed is sown thinly by lightly shaking the opened pods over
the prepared moss surface.  Any contact with the skin should be
avoided since natural secretions invariably prevent germination. 

After sowing, place the pots in light shade at temperatures of around
20 - 23C and to maintain high humidity, place a plastic cover or poly
film over.  Enough water should be added to the trays/saucers for base
of the pots to be standing about half an inch.  Much of this will have
been absorbed within an hour or so and will need topping up.  After
that, replenish the water every few days.  In the case of pots with
peat only, watering needs to be less frequent  - just enough to make
sure the compost surface remains constantly very moist but not sodden.
Any slight drying out will kill germinating seeds.

Germination of very fresh seed (much will probably be infertile)
starts to commence after about 4 weeks with a minuscule, greenish-
transparent 'protocorm' being formed first.  Growth in terms of a
thin, grass like leaf, will not become apparent for many more weeks
after that.  Generally, after 3 months, you should see short, almost
translucent, grass-like leaves which will be attached to slightly
ovoid, pinhead sized, 'corms' with one or two, very fine, short, hair
like roots.  Maintain existing conditions until a second stronger leaf
has formed, after which you can slowly acclimatise the young seedlings
to more normal room/greenhouse atmosphere.  Transplanting into a
sterile, peat based compost  - 75% peat, 25% finely rubbed dried
leaves such as oak plus a little powdered charcoal, can take place
once the seedlings are fully acclimatised and growing strongly.
Subsequent potting on/transplanting can take place using more
traditional potting media.

Bletillas are by no means easy to raise (few, if any orchid seeds
could be classed as easy) and are highly susceptible to moulds, fungus
flies, etc. during the first few months.   Although as a mature plant,
Bletilla striata is one of the easiest and most tolerant of orchids to
grow, it is virtually as sensitive and difficult as any orchid in the
early stages.  First flowering usually takes place at approximately 3
-4 years, but I have known instances where plants have taken up to 6
years.  Using the above method, I successfully raised a thousand or so
some 25 years ago, but concluded it was far simpler to buy young
tubers, which in those days could be bought very cheaply.

Dave Poole
TORQUAY  UK
http://www.ilsham.demon.co.uk/gardenviews.html
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