"Rod" wrote

Thanks for that Bob, this is a very new garden but I'm sure I could
arrange a damp mossy spot for next year, not sure about mycorrhizae
though, and they're critical for orchid seeds, probably less so for
plants. I need to do a bit more research.
Mycorrhizae are unlikely to be a magic bullet for everbody's
cultivation problems any time soon because the relationships between
fungi and plants are extremely complex and very little understood. I
doubt if there's any 'multi purpose' assembly of them that would have
a beneficial effect on a range of plants. Though you say you have your
orchids self sowing in pots containing other plants in old compost so
my previous statement is already looking a bit dodgy.
Probably getting hold of some good pot grown orchid plants may be a
possible way of getting some appropriate fungi.
BTW on another aspect of orchids being funny plants. In the old work
garden where I worked for 33 yrs, Broad leaved Helleborines are
cropping up is several parts of the place but I worked there for over
30yrs before I saw any.

Because the pots they have grown in have not been touched for more years
than they should be I am convinced there has been a build-up of mycorrhizae
in the soil probably because it had become poor and the old plants were
utilising mycorrhizae themselves. The Dactylorhiza that grew in my Pleione
pots would have had an easier time as, although it's only two years since
they were repotted, the Pleiones would have kept their own "orchid"
mycorrhizae with them.
Would you like to try some Pleione formosana Rod?

--
Regards
Bob Hobden
W.of London. UK