Orchid Growing Substrates

years. It is clear that it was an unknown species to science, and all attempts to find more
failed, as it was easy to collect such huge ferns. Hopefully they exist nearby, but it is doubtful,
as the whole area around that valley had been converted to rice fields for ages, only the valley
was untouched. His family is still in the tree fern business, and they commonly remove 4-7
meter tall tree fern, at the rhythm of a logging truck every 2-3 days.
o Some species are highly unsuitable for orchid culture for the medium or long term, whilst
there are no problems in Asia with most of the stocks, there seems to be a lot of complaints
from time to time arising from growers in Hawaii or Mexico, down to Brazi that some batches
killed many plants.
- Whilst highly appealing for orchid culture, and required for a few specific species, it appears that tree
fern does not have any commercial future, though it is worth noting that it is a very long lasting, and
stable, at least for some species, media.
Various bark
We will not mention at length the various bark, wood, pieces of cork, or slabs of teak are used to ‘mount’
orchids. The composition, behavior and chemical properties can vary tremendously from one type to another.
Sometimes, wood has been used in a potting mix, meranti sawdust was popular, and Norris Powell would use
crushed pine cones in his Paphiopedilum potting mix. One educated guess was that the resins and some
complex liposoluble compounds would degrade, and release ingredients that can promote plant growth. In a
similar way, one successful grower in Belgium used sawdust from his wood manufacture to pot his
odontoglossum, in clay pots. He would plant as well one plant of parsley per pot, and when the plant’s leaves
would start to bend, it was time to water the orchid. He was exceedingly successful, and grew some of the
best odontoglossum plants. Similarly, Charlesworth used sawdust in his later years, and in both cases it was
really fresh sawdust, mixed from many species. In both cases the tap water was very alkaline and the
marriage of water quality/sawdust seemed to be very successful.
Types of bark
Bark is the outer part of the tree. Several types of bark have been used, so we will start by some very exotic
ones.
Cryptomeria japonica bark
o
The famous ‘Cryptomoss’ from the Japanese. The texture and behavior is similar to tree fern
at first, and some excellent growers use it as a potting material. It is very acidic, and usually
many growers who used it had to apply some marble powder, or dolomitic limestone, to keep
the pH at a proper range. It has some oils, and some compounds, that have been sometimes
extracted and sold as a growth promoter. In fact, the ‘HB-101’ additive, promoted by the
Japanese as a cure and grow all product, is an extract from cryptomeria bark, containing
derivate of ‘resin acids’ (abietic acid, dehydroabietic acid…). Cryptomeria use is very marginal,
and very rare outside of Japan, though it seems to have some qualities at first. However most
Xavier Garreau de Loubresse
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