The majority of Australian epiphytic orchids can be easily grown in cultivation. Only one species is known to occur naturally in areas near Melbourne, it being Sarcochifus ausfralls. In contrast, there are around 100 species of epiphytic orchids in Queensland. Plants originating from Northern Queensland need growing conditions similar to their natural habitat.
When purchasing new plants, the first consideration should always be the conditions necessary for a plant to grow, for, without the appropriate conditions, these plants will not survive. For these reasons seedling plants (weather warm growing or not) grown locally are much better acclimatized to local conditions and are therefore hardier than plants imported from other climatic regions.Plants may be mounted in many materials such as compressed or natural cork slabs, branches of rough barked trees, black weathered tree fern slabs and pieces of weathered hardwood. Brown tree fern slabs contain substances, which are toxic to orchid roots and are not suitable hosts. Those species, which have pendulous or creeping rhizome (Dendrobium teretifolium (Dockrillia) and Dendrobium monophyllum), should normally be mounted.
As with other orchid species pests can be a real problem in growing native orchids. In fact some pests are attracted to native plants before attacking any other species of orchid. Snails, slugs, mealy bug, scale, fungi, aphid, grub, grasshopper, rot, and man are the most common problems to name a few. Control as for any other orchid species.
The Aboriginal tribes used native orchids such as, Spiranthes, Caladenia, Glossodia, Diuris Microtis, Prasophyllum, Thelymitra, Edochilus, Acianthus, Dipodium, Lyperanthus, Geodorum, and epiphytes such as Cym. Madidum, Cym. Canaliculatum, and Speciosum as a source of food. They also chewed various orchids as medicines for coughs, colds, and dysentery.
Epiphytic orchids respond to the regular application of fertilizers by producing strong healthy growth. Fertilizers are best applied during spring and early summer while the plants have a long growing period ahead of them. Late applications of fertilizers may delay dormancy and interfere with flowering. Organic fertilizers are excellent for orchids because they release their nutrients in a slow, gentle manner over a period of time. Blood and bone and hoof and horn are fairly commonly used to promote orchid growth. Liquid fertilizers are an excellent means of promoting healthy growth. Applied at less than the recommended strength means you can apply more frequently, which helps in producing much better growth.
Many epiphytic orchids grow well on a slab or a section of a tree branch, and relish the extra air movement and rapid drying which occurs after watering. Plants grown on slabs are easily moved and can moved about until a suitable position is found. Orchids grown on slabs require fairly high humidity and bright light. Orchids with a creeping habit or pendulous stems grow best on a slab, where as those with crowded, erect pseudobulbs are much better accommodated in a pot.
Fertilizers for Ground Orchids
We have seen that most terrestrial orchids rely heavily on a mycorrhizal fungus for their survival. This relationship can be readily upset by the excessive use of fertilizers and hence any fertilizing of terrestrial orchids must be carried out with care. A small quantity of blood and bone (10 grams per 9 litres of mix) added to the mix would be beneficial. One or two applications of quarter strength fertilizers can also be of benefit to some species.
Mulching the soil surface with a thin layer of fine leaves has the advantage of reducing moisture fluctuations in the upper layer of soil and inhibiting the germination of weed. It also reduces soil splash when watering, resulting in less leaf rot. The best mulching material is chopped she-oak needles, but the fine sieved leaves from under tea trees can also be satisfactory. The mulch should be applied when repotting so that the new shoots grow up through it.
Pollination Native Orchids
Dendrobium smililee is the only Australian orchid that is known to be bird pollinated. The flowers lack fragrance are often pendant and contain nectar. The bird is Bush Canary or Yellow Honeyeater. Beetles are frequent visitors to the flowers of large species of Prasophyllum, Microtis parviflora, Microtis unifolia and Peristeranthus hillii.
Calanthe tripilcata are sort after by moths, Habenaria triplonema like to be pollinated by Hawk moths, Bulbophyllum weinthalii attracts blowflies, Microtis parviflora are also visited by small black ants, Rhizanthella gardneri are pollinated by termites.
Phaius, Calochilus, Caladenia, Thelymitra, Geodorum, Spiranthes Acianthus Eria, Chiloglott is are self pollinated.
NEVER SAY DEAD IN RELATION TO NATIVE ORCHIDS
Far from being difficult and hard to grow, orchids are quite tough, adaptable plants. Several years ago Australian native orchids were being transported in cardboard cartons. When the plants were unpacked the cartons were set aside for future use. Almost a year later to the very day a cardboard carton was picked off the shelf of a garden shed to be re-used. Inside was a small plant, Dendrobium kingianum
that had been over looked the year before. The plant was dry and shriveled but still alive. It was placed in a mixture of brown sugar and water for 4 hours, then planted in a small terracotta pot, followed by normal watering and fertilizing. Next year it had recovered sufficiently to bloom and has now developed into a flourishing specimen
that has a host of blooms every spring. Few other plants could have survived such an ordeal.
These notes have been used at our Cultural and New Grower’s Meetings. They are from various sources and we thank the authors.
All articles are supplied in good faith and the Bribie Island Orchid Society and its members will not be held responsible for any loss or damage.