ADELAIDE ORCHIDS 16 PINE ROAD WOODCROFT SOUTH
AUSTRALIA 5162
OR FAX 618 83221546 OR EMAIL [email protected]
TUBERS :
CALADENIA ; CORYBAS
; CYRTOSTYLIS ; DIURIS
; ERIOCHILUS ; LEPTOCERUS ; LYPERANTHUS
; MICROTIS ; PTEROSTYLIS
; THELYMITRA.
CULTURE NOTES
Australian
Terrestrial orchids are easy to grow. In Adelaide Australia they thrive in a
shade house of 50% shadecloth. Growers in Northern Australia will need to
provide overhead protection from rain in Summer. Many Victorian growers provide
overhead protection from excess Winter rain and water by hand. In very cold
areas an unheated glasshouse may be required for frost protection although
light frosts do not worry the majority of species. Australian ground orchids
follow an annual growth cycle comprising 6 - 8 months as growing plants under
cool (5-20c max, 0-14c min) moist conditions and 4 -6 months as dormant
tubers in hot dry (18-40c max, 12-30c min) conditions. All species like good
air movement and will not thrive in a stuffy humid atmosphere especially if
temperatures are high. Some species prefer heavy shade, others full sunlight,
but most will adapt to a wide range of light intensity. If the leaves and stems
are weak and limp or if the rosettes are drawn up to the light then shading is
too dense and the amount of light should be increased. The Spring flowering
species like higher light intensities at flowering time and flowers may have
pale colours under dull conditions.
The soil should be kept
moist at all times during active growth by watering gently if there is no rain.
Hand watering is especially necessary in Spring as soil in pots dries out more
rapidly than in the garden. Watering must be done slowly so that the mat of
needles on the surface of the pot is not disturbed. Slugs and snails love these
plants and must be kept under control. Raising the pots off the ground on
galvanized steel benching is very effective in controlling these pests. Be very
careful with fertilizers because some terrestrials are easily burnt or even
killed by overuse. Chiloglottis, diuris and pterostylis are very hardy and will benefit from weak applications
of folia feed in the early growth stages.
The
new tubers are produced in Winter - Spring. Most of the species on this list
are colony types, that is they multiply each year by forming several tubers per
plant. Some time in Oct-Nov the leaves go yellow and then brown and dry as the
days get longer, hotter and drier in late Spring. After the leaves have turned
yellow, let the pot dry out completely to dry the old roots and tubers
otherwise they will turn into a soggy mouldy mess and rot may infect the
adjacent new tubers.
The pots can be knocked out
and the tubers examined in Summer without harm, in fact we find at the Nursery
that the best results are obtained if the tubers are repotted in fresh soil
mix each year. Our soil mix is 45%
loam, 50% sand and 5% organic matter with a little blood and bone fertiliser
added. A 5mm sieve is a useful tool for separating tubers from soil. Replant
the dormant tubers with the tops 20mm deep. Cover the soil surface with a mulch
of pine or sheoak needles, chopped to 20 - 50 mm lengths, to prevent erosion.
Repotting is normally done in November, December and January. Dormant tubers
travel well and we ship them to many parts of the world each Summer.
Keep the pots shaded and
allow the pots to dry out between light waterings until the end of February
when they may be set out in their growing positions and watered a little more often.
The tubers of some species will rot if kept wet during the dormant period,
others will produce plants prematurely which are then attacked by pests such as
thrip and red spider and fungal diseases in the warm weather. Each tuber sends
up a shoot to the surface in Autumn and leaves grow rapidly in late Autumn -
early Winter as temperatures fall and the rains set in. Pterostylis are usually the first to appear in March, followed by diuris and thelymitra in April, caladenia
in May and corybas in June - July.
Plants sent bare root in May-Aug should have the spagnum moss packing removed carefully. Pot up immediately into 125 mm or 150mm standard plastic pots. Half fill the pot with soil mix. Hold the plant so that the final soil level will be at the same point on the stem as before shipment. Fill in around the roots with more soil and gently firm the soil around the plant. Cover the soil with chopped pine needles. Water gently but thoroughly to settle the soil. Lift the orchid leaves on to the top of the pine needles in necessary. Sun loving species (diuris, microtis, thelymitra) prefer a brighter location for good growth. Corybas like the shadiest corner.
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