"Dave Poole" wrote
Hi Janet,

Having grown Phalaenopsis and a good many other epiphytic
(tree-perching) orchids since I was 'knee-high to a grasshopper',
which is now over 40 years there is nothing in the claim that they
have to be grown in clear pots. If you think about it, clear plastic
pots are a trendy introduction of the past couple of years at most,
but Phalaenopsis have been grown conventionally and very successfully
in this country since before 1850. You don't need rocket science to
work out, whether they must have clear pots or not.

That said, a good many roots will try to grow on the compost surface
and out into the air or down the outside of the pot. These should not
be cut away since they will absorb nutrients and atmospheric moisture
(most importantly), but also partly function as leaves as well.
However, their photosynthetic contribution compared to that of the
leaves is quite minimal and by no means essential. When roots are
exposed to full light and kept growing actively, a good many plants
develop green-tinged roots and that includes those that normally grow
in the ground.

Chlorophyll (the 'green stuff) or more importantly chloroplasts (the
organs which contain chlorophyll and carry out the photosynthetic
process) are not limited just to stems and leaves. They can and will
develop on any part if there is sufficient light exposure. Try this
out, stick a bit of fuchsia or Impatiens in a glass of water and
instead of potting it as soon as the roots form, allow them to carry
on growing. They will turn greenish and start photosynthesising in no
time - as will the roots of almost any other plant.

Anyway question was asked about growing orchids and Nursery manager from
"biggest Plant centre in country (in Ware)" advised that you grow
orchids in clear flower pots as their roots need to see the light.

Biggest 'Plant Centre' immediately smacks of little or no specialised
knowledge!

... pointed out that her orchid was still flowering after 24 months
but was in ordinary pot but that was pooh poohed as good luck.

Aha! Proof positive! The man clearly knows relatively little and has
followed some cleverly worded marketing blurb in favour of clear
plastic pots. They are a stylish innovation of no great practical
value. A bit like galvanised buckets as planters on the patio. When
the trend for minimalism bites the dust, so will a lot of these.

Janet, the key to success in growing Phalaenopsis or any other
epiphytic type is to get a good balance of air and moisture around the
roots. They naturally have most of their roots exposed, but this is
mainly to trap falling detritus from higher up and absorb moisture.
Any photosynthesis is incidental and not essential. Allow any roots
that want to 'hang out' (orchids were never 'neat growers', nor will
they ever be) and water whenever the compost becomes very slightly
dry. Provide airy, buoyant conditions, sufficient warmth, reasonable
light but not direct sun and you are 95% there. Growing in a clear
plastic pot will not make a scrap of difference in the face of these.
If you prefer terra cotta coloured ones (I go for black meself), you
carry on girl. Good growing practice and not style will always win
the day.

I totally agree with David, if you were to go to your local Orchid Society
Show you would see beautiful Orchids grown to perfection and very few, if
any, in clear pots.
The Orchid Society of Great Britain (OSGB) had their annual show at RHS
Wisley a couple of weekends ago, not that most visitors to the gardens knew
anything about it as it wasn't signposted, and I don't remember seeing any
in clear pots.
What you will see in the shows is some growing on a lumps of mossy bark and
others growing on pieces of Tree fern trunk because that's how they grow in
nature. You need automatic misting to be successful with that method really.

There are some specialist orchids that have no leaves and these do all their
photosynthesis entirely through their roots, these do need to grow on
bark/tree fern/brick so the roots get light. Never heard of anyone using
clear pots for them.

--
Regards
Bob
In Runnymede, 17 miles West of London