2017 October Cultural Notes

Steve Howard’s October Australian Epiphytes and Terrestrials Orchids Cultural Notes for Adelaide’s conditions.

Epiphytes

  • October sees many native epiphytes finish flowering and shortly it will be the best time for potting on and division as new growths are due shortly. The earlier you start, the more time the orchid has a chance to initiate new growth and mature it in time for next years flowering.
  • Remove spent flowers as leaving them on the plant in wet and humid conditions leads to rot caused by botryitis.
  • Be aware that aphids are in big numbers now and will cause grief to flowers and new growths.
    • Malathion at 1 ml/ litre of water will knock them out.
    • Repeat fortnightly for 6 weeks to break the breeding cycle.
  • Apply lime to plants grown in bark to counteract acidity.

Terrestrials

  • Most terrestrials nearing completion of the season.
  • Start drying off once leaves start yellowing. Keep water up to those staying green.
  • Additional shade helps now as suns intensity increases
Epiphytes in flower (1)

Annual NOSSA Spring Show

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2017 August Cultural Notes

Steve Howard writes cultural notes for Adelaide conditions. These are his notes for August; for both epiphytes and terrestrials.

WATERING

Mounts daily.

Pots weekly. Small pots twice weekly depending on weather. Drier conditions for hot cold types. Terrestrial pots can dry out faster on warmer days so keep a watch on conditions.

FEEDING

Epiphytes: Recommending feeding towards months end as days lengthen. Many plants in strong spike growth and flowering now.

Terrestrials generally don’t need to be fed although weak organics like Seasol and Powerfeed applied in low doses can benefit colony type greenhoods.

PESTS AND DISEASES

Epiphytes: Botrytis will rot new buds in cold damp weather as fast as it attacks new growths from now. Aphids will increase sharply this month and favour new growth and spikes.  Pyrethrum sprays eco friendly and work well, so does a hose but dry spike straight after.

Some terrestrials will rot this month if conditions have been too wet or stagnant over winter. Note this for next season and add more drainage if this has been an issue.

 

GENERAL

Epiphytes: Keep flowering plants under cover  to enjoy. Soon will be the time to start thinking about re-potting and division as spring nears.

Keep flowering terrestrials out of strong winds and heavy rains as flower stems on some varieties are quite weak when grown in cultivation

Additional:

Later August will produce some warmer drying days as spring nears. Ensure small pots and plants don’t dry out at this time. Good time to check out seedling lists and prepare orders to ensure your plants arrive at the commencement of a new growing season.

den-alick-dockrill-paleface-jb-1

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2017 July Cultural Notes

Steve Howard regularly writes orchid cultural notes for various orchid clubs in South Australia. His notes are tailored specifically conditions in Adelaide. The following are his notes for both epiphytes and terrestrials for the month of July.

Epiphytes

  • Water mounted native epiphytes daily; pots weekly and small pots twice weekly depending on the weather. Hot cold types require drier conditions. Generally none to once monthly for me.
  • Colder weather slows down their metabolism in winter. Foliar feeding is beneficial.
  • Keep water out of new growths to avoid rot. Clones prone to this need to be moved under hard roof cover to keep drier.
  • Check under leaves for scale.
Epiphytes in flower (1)

Annual NOSSA Spring Show

Terrestrials

  • Weed pots as the weeds appear and ensure that they don’t get too wet.
  • Remove rotted growths.
  • Start baiting for slugs and snails as spikes emerge from protective sheaths.
  • Provide hard cover during wet weather to stop botrytis spotting and rotting out spikes.

Thelymitra plants in pots

CONTROLLING SCALE ON NATIVE ORCHIDS

INTRODUCTION

There is a lot of information on the web about treating scale, some relevant to a specific country, some accurate, some not and much that is contradictory.

The following information is based upon treatment methods that the Native Orchid Society of South Australia (NOSSA) growers have found most effective.

WHAT IS SCALE?

Scale are tiny sap sucking insects of which there are several species in Australia. The female adults build a shield-like cover for protection. The shields are often brown but can be white or red. The shield can be up to 3mm in size. Once a shield is built the adult does not move about but stays in the one position. Ants farm scale as they exude a honeydew sap, a food source for the ants.

Immature scale or crawlers do move about. These can be a different colour from the adult eg juvenile brown scale can be yellow, other species can have grey juveniles. They are lightweight no more than 1mm and easily windborne.

The life cycle is short, and for many species, within a month there is a new generation of scale. Scale multiply rapidly.

Scale tend to attack epiphytic orchids. Evergreen terrestrial orchids may be affected but not the deciduous ones.

EFFECTS OF NOT TREATING SCALE:

Apart from making the plants look ugly, scale left unchecked can

  • infect other plants
  • weaken the plant leading to death of the plant
  • make the plant worthless for shows
  • develop secondary infection of sooty mould
    • treating the scale will treat the mould
Scale on Dendrobium.jpg

Left untreated the new growth will eventually become infected

SCALE PREVENTION:

Inspect and Monitor plants

  • check leaves (both upper and underside), crevices, sheaths, pseudobulbs, stems, etc

Quarantine and treat new plants before introducing them to the orchid collection

  • newly acquired plant can be a major source of scale infestation
  • for thoroughness, use both a contact and systemic spray (see below Types of Sprays)

Preventive spraying

  • schedule spraying 2 – 4 times a year

Consider relocating ferns if they are under orchid benches as this can often be a host for brown scale.

Control ants

  • If free-standing bench or hanging pots are free of scale and plants are not touching any other surface than applying Vaseline around each of the feet/lower part of the hooks will prevent ants and crawlers from moving into the area.
  • Vaseline is waterproof and so will be effective for a long time.

SCALE PREDATORS:

Biological control alone appears to be ineffective but the following is a list of known predators

  • Crypotlaemus montrouzieri Native ladybird feed on mealybugs and felt scale
  • Mallada signata, Green Lace Wings, feed on aphids, spider mites, various scales, mealybugs, moth eggs and small caterpillars
  • Chilocorus beetles
  • Aphystis wasp species

TREATMENT:

Scale are hard to eliminate entirely. Vigilance and persistence are important factors in controlling scale.

Treatment works either by

  • a direct contact spray whereby the insect is suffocated by smothering. This is effective for all stages of the life cycle but particularly for the adult under its shield.
  • an application of a systemic chemical.
  • or a combination of both.

For treatment to be effective the leaves (both upper and underside), crevices, sheaths, pseudobulbs, stems must be thoroughly drenched with the spray of choice.

Types of Sprays

Contact Sprays

Whatever type of contact spray used, treat every 2 weeks for three treatments

  • Soapy Water (for those who like using home-made remedies)
    • Using pure soap (not detergent), suds up a bar in a bowl of water, and pour into a spray bottle.
  • Homemade Horticultural Oils
  • Eco-Oil (Pest oil)
    • No petroleum derivatives; registered organic substance
    • Do not spray on very hot days as it can cause burning.
    • Always dilute (2.5 mls per 1 litre as per instructions on label), never use neat
      • It is important to dilute, as the oil can also block the leaves stomata and so suffocate the plant.
      • It is a foliage spray and should not be used on the plant roots.

Eco Oil.jpg

Chemical Sprays

Whatever chemical spray is used, repeat within 4 weeks of the initial treatment and then as often as necessary.

Ideally, it is best to use multiple systemic sprays to avoid the scale becoming resistant to the chemical.

  • Confidor
    • Active ingredient Imidacloprid, an insect neurotoxin, is absorbed by the plant and then ingested by the insect
      • low toxicity to humans and pets
      • but use heavier drenching rather than fine mist to avoid inhalation
    • Effective for about 2 – 3 weeks
      • broken down by light so remains in pots and soils for awhile
    • Follow manufacturer’s instructions at the minimum recommended strength.
  • Defender
    • Active ingredient acetamiprid
    • Low toxicity to bees (although bees are not usually a problem in an orchid house)
  • Fipronil
    • High toxicity
    • Harder to obtain
    • 80 – 95% kill rate for slugs and snails

NB: Do not use the contact and chemical spray at the same time

  • Wait a week between using the different types of sprays.
      • Spraying too soon will negate the effects of the first spray.

confidor

Additional Treatment

Despite what application is used, all need the following treatment

Rub the scale off taking care not to damage the leaves

  • Use either toothpick, fingernail, toothbrush or cloth/tissue
  • Rubbing the scale off allows for
    • detection of new infestations
  • eggs under the shield to be killed

Thoroughly disinfect any recycled pots

Dispose of all debris as eggs and scale can survive for weeks and reinfect the plants

 

REFERENCES:

Oliver D, Scale and its Control Oliver, Orchid Societies Council of Victoria, http://www.oscov.asn.au/articles3/scale.htm accessed 5/1/17

Johnson PJ, Scale, Orchids – The Bulletin of the American Orchid Society, September 2003, http://www.aos.org/orchids/orchid-pests-diseases/scale.aspx accessed 5/1/17

Manners A, Scale Insects: A difficult problem that can be managed, 2015, Agri-science Queensland, Department of Agriculture and Fisheries https://www.ngia.com.au/Category?Action=View&Category_id=682 accessed 5/1/17

Imidacloprid https://en.wikipedia.org/wiki/Imidacloprid accessed 5/1/17

Eco-Oil http://ecoorganicgarden.com.au/products/pest-disease/eco-oil/ accessed 7/1/17

Les Nesbitt, NOSSA, pers comm

Kris Kopicki, NOSSA, pers comm

Richard Austin, ANOS Vic, pers comm

Gleanings From the Journal: Rescuing apparently ‘dead’ orchids Parts 2 & 3 of Three Parts

This week we continue with both Part Two and Part Three of Brendan Killen’s Rescuing Apparently ‘Dead’ Orchids  which appeared in the Volume 31 No 9 October 2007 and Volume 31 Bi 11 December 2007, respectively.

Rescuing apparently ‘dead’ orchids. Part 2 By Brendan Killen

PLANT #2 – Dendrobium Alick Dockrill “Pale Face”

untitled

The cane pieces of this plant were inserted into a bark mix at the same time as the canes of Den. Jayden ‘JANE’ [See the July Journal] were inserted into sphagnum moss. The outcome is three healthy growths.

Note the dried ends of the canes where they were cut into separate pieces. As you can see from the photograph, I used a green twisty to hold the canes in the bark as a fairly solid bunch – I find this is the best way to keep the canes still whilst they are developing sensitive new growths. I have found that no matter how bunched-up the canes are, the new growths always find a way to the surface.

untitled

Here is a different angle on the new growths with my fingers providing some perspective on the size of the growths.

Note that they are significantly larger that those on the Den Jayden ‘JANE’, with the same time in the pots.

I do not consider this evidence of the worth of bark compared to sphagnum moss.

I find that different hybrids and species behave quite differently in terms of their speed and timing of production of new growths. I believe that it is a function of what species are in the background of these plants and the time of year the rescue is undertaken.

Here is the same plant 5 weeks later. The new roots are protruding from the pot and the new growths are extending themselves – all of this at a time where severe water restrictions limit me to two waterings each week by watering can!

Plant 2-3 Den Alick dockrill 'Pale Face'.jpg

Plant 2-4 Den Alick dockrill 'Pale Face'.jpg

A further 4 weeks of cultivation and bright, warm weather has fully extended and hardened the new growths.

The larger growth should produce a flower spike this Spring.

Dendrobium Alick Docrill “Pale Face” (Photographer: Josh Bridge)

TO BE CONTINUED

 *********************

 Rescuing apparently ‘dead’ orchids. Part 3

By Brendan Killen

Plant #3 – Dendrobium Sarah Jane ‘Purvis’

This is a plant that the late John Purvis gave me just before he passed away. Because it is a special plant to me, I cut an old cane into three pieces to produce a back-up plant, just in case my piece of the original fell foul of the orchid gremlins.

Journal

As you can see, it is the least developed of the three plants featured in this article. And yet, the parent plant has produced two magnificent new growths in the same period. I feel that the 12.5% of Den. bigibbum and 12.5% of the hot growing Den. tetragonum var. giganteum have influenced this. This new growth has probably been encouraged since the relocation from Adelaide to Brisbane where the temperature differences overnight are more subtle than in the Adelaide Hills where the plants were previously cultivated. The two hot growing species in the plant’s background were probably held back by Adelaide’s much cooler overnight temperatures. Anyway, this is purely conjecture on my behalf. What is important is that I now have a developing back-up plant for one that I treasure dearly.

Dendrobium Sarah Jane ‘Purvis’ (Photographer Josh Bridge)

SUMMARY

The thrust of what I have written is simple – don’t give up on treasured plants that look like they have expired, because there is always hope so long as the canes haven’t turned into fermented mush! The technique is as simple as cutting canes into lengths where you have at least three, preferably four, segments from which new growths will materialise. Use sterilized cutting tools to avoid contamination of the canes. Once the new growths have emerged, give them time to produce healthy root systems and let the new canes harden before potting-on. The best time I have found to pot-on the new growths is early autumn.

****************

Thank you to Josh Bridge for supplying images of the flowers of Dendrobium Alick Dockrill “Pale Face” and Dendrobium Sarah Jane ‘Purvis’ as they were not in the original articles.

***************

Another technique demonstrated by John Gay at one of the NOSSA meetings a couple of years ago was to take the apparently dead canes of an epiphytic orchid and seal them in a plastic bag with a small piece of damp sponge (or other cloth) and leave them in the shadehouse.  Do not let the sponge dry out.  So long as there was a bit of moisture, there was a chance for new growth on the shrivelled canes.  Once the growth was obvious, pot on as normal.

CULTURE NOTES FOR EPIPHYTIC ORCHIDS in ADELAIDE 2016

Dendrobium speciosum

Epiphytic orchids grow on trees or rocks (lithophytic), where they are dependent on their host for support but not for food.

CULTIVATION

The majority of Australian epiphytic orchids can be easily grown in cultivation.  Most can be grown in Adelaide if the correct cultural requirements are provided.  These include controlled glasshouse conditions, shadehouse conditions and, in some instances, in the garden.  Only a few species are able to tolerate the cold winter months in Adelaide without extra protection, and all need protection from frost.

CONTAINERS AND MOUNTS

Plants can be grown in pots or mounted on an appropriate substrate. Pots may be either plastic or terracotta.  Terracotta pots are porous and dry out more quickly than plastic.  If terracotta pots are used, their drainage holes may need to be enlarged to give very good drainage.  Plants should be potted into the smallest pot, which comfortably accommodates the base of the plant.

Plants may be mounted on 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.  Those species that have a pendulous habit e.g. Dendrobium teretifolium should only be mounted.

POTTING MIX

Most potted orchids require a mixture made up of bark chips (fir or pine), to which may be added charcoal, gravel or polystyrene chips, in which to grow.  Bark used should be aged and preferably purchased as graded hammer-milled bark, not shredded bark.  Fresh pine bark contains compounds, which are toxic to orchids.  Before use fresh pine bark should be soaked in water changed regularly, to remove toxins.  This may take 3 weeks.  If in doubt as to the freshness of the bark, treat as above to be sure.

Depending on the size of your plant, bark may vary from 5-7mm up to 20mm in diameter, and sieved if necessary to remove fine particles and dust.  Other substances such as scoria, leaf mould and coarse grit may also be added according to the requirements of the particular species involved.  Whatever the substrate, be it a slab or potting mix, the essential thing with all epiphytic orchids is to always provide good drainage for the plant’s root system.  This ensures no, or minimal, root rot of plants.

Repotting is necessary when the potting mix breaks down resulting in poor drainage, the medium goes stale or when the plant over grows its container.  The best time to repot is during the spring, after flowering, when the plant starts to actively grow again.  Try to repot every 2-3 years.

Potting on:  If the plant has overgrown its container and the mix has not deteriorated, it can be potted on into the next sized pot with minimal disturbance to the root system.

D kingianum composite (2)

GROWING ENVIRONS, HOUSING

Garden Culture

Several species may be grown outside in Adelaide, provided they are given a position sheltered from frosts and hot drying winds.  They should receive daily supplementary watering during the summer.  They may be tied on to trees with rough non-deciduous bark or grown on rocks.  Microclimates can be created in areas of the garden using screens for protection and other plants to help maintain a humid atmosphere.

Bush house, Shadehouse

These structures are built to give protection from frosts, strong winds and sun and to provide extra humidity for plants.  They may be covered with shadecloth or tea-tree and should have a solid south wall.  They provide protection, but still allow for good air circulation around the plants.  A water impervious roof, e.g. fibreglass or polycarbonate sheets, will protect plants and flowers from excess water in the winter.


Unheated glasshouse

An unheated glasshouse gives more protection to the plants, achieving higher temperatures during winter days, and better humidity.  It may be made from glass or other materials such as fibreglass or polycarbonate sheets.  Additional shading with shadecloth or paint is necessary from October to March-April.  Adequate ventilation must be provided, by using ventilators under the benches to let in fresh air, and roof ventilators to let out hot air.  Alternatively, air circulation can be achieved using fans.  All orchids love fresh air.

WATERING

All plants need to be watered frequently from October to April, during the growing period.  Most species require watering once a day or twice a day if the weather is particularly hot or drying.  Ensure that plants dry out between waterings.  During winter, watering once a week should be sufficient for plants in a glass house environment, although plants which are mounted may be misted (a very fine spray) more frequently.  Water early in the morning of winter days to ensure that the leaves of the plants have dried off by night.  Water lodging in leaf axils in cold, comparatively still conditions, renders that area liable to fungal attack.  Humidity may be maintained by watering the floor and under the benches, particularly in summer.

Rainwater, if available, is preferable to mains water, which can. In some cases, increase in salinity to a level, which is harmful to good plant growth.

FERTILISING

To promote healthy growth of all epiphytic orchids, a supplement of half strength liquid fertiliser every two weeks may be used during the growing season of the plant, i.e. November to April.  Mature potted plants can be sparingly fertilised with slow release pellets.  Too much fertiliser will lead to a salt build up (especially in charcoal), which will harm the plants.

PESTS

Pests will become a problem in any shadehouse or glasshouse if the grower does not keep a watchful eye out for them.  The shadehouse or glasshouse should be kept free from weeds, decaying organic matter and rubbish, as these are the places where pests feed and accumulate.  Overcrowding of plants will also encourage pests to thrive.

Pests can be easily removed by squashing if they are in small enough numbers.  A pest strip hung in the glasshouse successfully controls many pests. Unfortunately the environment of a glasshouse, which suits orchid culture, also provides a suitable environment for the spread of pests.  Poisonous chemical sprays should only be used after non-toxic preparations have been unsuccessfully used.  These chemicals also destroy the natural predators of insect pests, upsetting the natural balance.

Caution should be used when handling chemical sprays as many are very toxic to the user as well as the pests.  The manufacturer’s directions and warning labels should be read carefully and recommended strength adhered to strictly.

DISEASES

Australian epiphytic orchids are generally disease free.  Fungal infections may occur, susceptible areas being new growths, especially in young plants.  These can be kept to a minimum by maintaining good air movement and avoiding water remaining in leaf axils for too long.  Broad spectrum fungicides are suitable to control severe infections.

PLANT CARE

Removal of any dead leaves, pseudobulbs, etc, not only enhances the aesthetics of the plants, but also lessens the chance of further deterioration.  These areas are also the places where pests may accumulate or diseases harbour.

Dendrobium bigibbum

Dendrobium bigibbum

Gleanings From the Journal #3 – Native Orchids The Epiphytes: August

The following article is from Vol. 32 No 7 August 2008 Journal of the Native Orchid Society of South Australia Inc.

Dendrobium speciosum

Dendrobium speciosum

Native Orchids. The Epiphytes: August.
Steve Howard

Movement of our natives towards flowering is often rapid.  How often do we look at our plants thinking that they will never be out in time then take a look the week after and they have doubled in size.  Dendrobium speciosum is a classic example of this.  One minute the plant is covered in acorn like flower buds then a week later there are bunches of flowering buds everywhere.  There is the temptation to force them on but I would leave that until the last two weeks prior to show before making that call.  Then we have the Sarcochilus.  These can stay in bud for months and not do a thing then suddenly they are away.

On the epiphyte side we should have a heap of buds everywhere on the flowering plants.  They key is to keep these under cover and away from rain and also slugs and snails that have a nasty habit of chomping into them.  Rain exaggerates fungal problems that will rot out a flower spike overnight.  Also avoid temperature extremes, especially once the buds start showing on a lengthening spike.  Bud drop occurs quickly and the loss of even one bud will sway the judge’s decision.  Even and strong light now becomes important especially for those epiphytes with Den. speciosum and Den. kingianum in the backgroundThe reason is we need to create strong upright racemes to support the flowers.  No point having the spikes hanging over the side of the plant and then have the flowers doing the same.  Some species do have this trait and as such do not make very good parents if this trait is passed on in hybridisation.  I like my flowers to look at me and cannot see the point in lying on the ground and looking up at the plants on the bench.  Strong light will assist this spike development as does the potassium and potash in the fertiliser.  This is also a reason we tend to avoid high nitrogen feeds in our feeding programme.  Even light is also important in order that the flowers will be evenly distributed around the pot as opposed to all facing the one way.  Hanging flowering plants is one way we can get this even light.

Now is also a good time to clean up our plants before flowering.  Remove husks over the canes, remove dead leafless canes and trim and clean the leaves.  It is easier to do this now whilst the spikes are on the small side.  Also give the pots a scrub too.  All of these tips will help make things a little easier when it comes time to prepare the plants before show.  Also make sure you have some fresh topping for the pots.  It’s these little things that helps improve the presentation of our plants.

Only remove leafless canes if you think they have completed their flowering potential as many will flower for years after losing leaves or if the cane affects the appearance of the plant.  If the forward growths are struggling under no circumstance remove the leafless cane unless it is absolutely dead as the struggling plant would be relying on stored nutrients in this cane to survive.  I would then concentrate on why is the plant in the state in the first place.

Dendrobium bigibbum

Dendrobium bigibbum

Even though we are two months away from re potting and dividing our plants it is now time to take stock of what plants will be potted on, divided or sold off on the trading table.  That way we can arrange pots, mix etc in preparation.  The other thing I am looking at now is where am I going to move my plants this year.  Last years heat exposed many plants that are susceptible to heat and with the probability that this will happen more frequently in the future there is the need to move these prone plants from where they are at present.  Leave them where they are and the same thing will happen again.  There will also be the need that these tender plants be removed from the collection and the emphasis placed on more hardy species and hybrids.

Watering will be dependent on the hybrids you grow and where the parents originate from.  Most of the hot/cold type have the tropical hard cane types in the breeding eg Den. bigibbum and these require dry winters so we need to take this into account here.  I do not dry them out completely but then again don’t water them frequently either.  I aim for slightly moist at all times to keep the roots in good condition.  The others with Den. speciosum, kingianum, falcorostrum all come from cooler climates that receive winter rains and as such can handle being damp over winter.  Avoid over wetness as this will be to the detriment of the plants.  These plants require a short dry period after flowering to mimic the same dry spring period experienced in the areas where most of them come from.  I find that with our reduced rainfall of late, nature provides my plants with enough water apart from the mounted plants that get the odd mist or squirt.  Any watering should be confined to the warmer part of the day after lunch.  Early morning squirts with water from a hose that has been sitting on a frozen ground all night will not do your plants any favours.  Feeding during these cooler months is infrequent and if you miss them for a month or more will not cause too many issues.  Plants under cover get watered every couple of weeks and these are usually the hot colds.

You will have a few late season new growths reaching full size.  Keep an eye on these as they are very prone to rot when water sits in the axils of the new growths.  If you notice a growth go reddish or yellow it is a good bet that it has rotted.  You can cut the growth off below the infection and treat with a fungicide.  I then dry the plant out as a precaution and take a mental note.  This plant will always be prone to attack.

My plant of the month is Den. aemulum, the feather orchid.  This compact growing epiphyte comes from central NSW (New South Wales) to Qld (Queensland) and comes in 2 forms.  The iron bark form strangely enough grows on the iron bark tree, a heavily permanent barked member of the eucalyptus family.  It has small cylindrical psuedobulbs that grow in a radial pattern topped with two small and rather thick leaves.  Small white clusters of flowers that go pink as they age are borne apically over several seasons from the one cane.  The other form commonly seen is the brush box form.  This is the long caned variety and the two are found in similar areas.  These are not often seen in collections and have the habit of slowly fading away in cultivation unless their requirements of light, a suitable host and conditions are met.  I have several plants on different hosts and the results are mixed.  The best plant grows east on a slab of hardwood in a rather protected spot and is the brush box form.  The iron bark forms appear to struggle on mounts of Callistemon and paperbark.  Maybe it is the acidic gummy excretions from the bark of the ironbark that are missing.  These plants have not been used in hybridisation very much as they do not have the traits that hybridists are looking for.  Nevertheless I find them a very attractive flower when grown into a specimen plant and they will always have a place in my collection.  They are not easy to obtain and generally restricted to those that have permits to collect them from the wild.

Next month is September and with it the warming weather and a profusion of flowers.  We will look at a few tips to help with the presentation of show flowers but also look back at those that did not flower well or flower at all and see where we can improve and what went wrong.

Epiphytes in flower (1)

Annual NOSSA Spring Show

SHOWY SPECIOSUM

A very popular orchid grown in culture in South Australia is the epiphytic/lithophytic Dendrobium speciosum.  It is a showy species with a heady perfume.

Dendrobium speciosum

Dendrobium speciosum (Rock Lily, Rock Orchid) in culture

This species ranges along the eastern seaboard from Queensland just peeking into Victoria.  There are nine variations each with its own unique distribution.

But not only is it popular in South Australia, it is popular throughout the country.  The whole of the 2006 September issue of the Orchadian was devoted to a single article on D. speciosum.  The March 2016 Orchadian has three articles plus references to D. speciosum in other articles.

And then there is Gerry Walsh who is so passionate about this species that he has a comprehensive website – The Rock Lily Man – devoted to it.  Explore and enjoy his website.

 

The Orchid Club of South Australia has produced a fact sheet for growing this species in South Australia.

 

 

Growing Cymbidium canaliculatum in Adelaide 1983 and Now

In 1983, Ron Robjohns, NOSSA’s first treasurer, wrote a comprehensive series of articles about growing epiphytes in South Australia. Thirty years on Ron’s information for growing is still helpful and applicable for today. Any updates or extra information are in black text.

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL Volume 7, No. 11, December, 1983

GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns

Cymbidium canaliculatum

A most interesting orchid, also one of the few epiphytes to grow in Western Australia. It is credited with a southern limit of near Forbes in New South Wales, extending northwards to Cape Yorke Peninsula in northern Queensland and westwards across the Northern Territory to the northern areas of Western Australia. Although sometimes found in the near coastal areas of the eastern states it is primarily a plant of the open forests of the drier inland areas. In some of its habitats there is less than a 55 cm rainfall, summer temperatures of over 38⁰ C with a very low humidity and winter temperatures dropping to below freezing. While not exclusively, it is usually found growing in hollow branches or trunks of trees where its roots penetrate the decomposed wood and often grow to considerable length. No doubt the fact that the roots are protected from the heat enables it to survive and even thrive under such harsh conditions.

It frequently grows to form large clumps of crowded pseudobulbs having two to six leaves which are thick, rigid and channelled and are from 10 to 50 cm long and 2 to 4 cm wide. The racemes are up to 50 cm long and can be erect or pendulous with up to 60 extremely variable flowers about 2-3 cm across.

The colours range from green, brown, purple, dull red or a combination of those colours and may be either with or without spotting, the labellum, however, is usually white with red markings.

I find that C. canaliculatum responds reasonably well to cultivation and have grown and flowered it in plastic planters filled with a mix of charcoal, pine bark and rotted hardwood, also in hollow logs filled with the same mixture. Propagation from backbulbs has been with limited success and it looks like about a six year project from planting to flowering.

An established plant can take full sun and will withstand our winter frosts without detriment. Fertilising has been with the occasional dose of liquid fertiliser. When purchasing from a nursery I would suggest medium to small plants as although large clumps may look attractive they usually have had the root system almost completely removed – an operation to which they do not take kindly.

Cym caniculatum drawing

Les adds that Cym. canaliculatum should be kept dry from Anzac Day (25th April) to September when the flower spikes appear.

Gleanings from the Journals #2 – Harold Goldsack (27/6/1908 – 25/4/1989)

 

[Primary source material is the NOSSA Journals. Direct quotes from the Journal in blue and additional information in black.]

Sometimes gleanings take much time and effort to locate but other times there is an abundance of information just waiting to be picked up. This was the case when searching the Journal for information on Harold Goldsack.

Upon the death of Dr R S Rogers, Harold Goldsack became the leading authority of South Australian orchids. To quote Peter Hornsby (1977), NOSSA’s first editor, “Harold is undoubtedly the most experienced of our native orchid botanists and knows more of the history of our orchids than anyone alive.”

Though not a foundational member, Harold was one of NOSSA’s early members, joining at the end of 1977. He was both a grower of epiphytes – winning the Champion epiphyte for 1982 (Dendrobium x gracillimum) and terrestrials – producing the first greenhood hybrid, Pterostylis Cutie (baptistii x cucullata) which was registered on 5th March, 1982. At the meetings he gave talks, plant commentaries and judged the orchids. Outside of the meetings he was active in advancing the cause of Australian orchids. His enthusiasm influenced many people, one person being a young Mark Clements, current Research Scientist, Centre for Australian National Biodiversity Research, CSIRO, Canberra.

It is not surprising than that in 1984 he was made NOSSA’s second life member.

 

Bob Bates wrote an informative biography in Harold’s obituary.

Journal 1989 Volume 13 No 4 May

Vale Harold Goldsack.

It is with sadness that we announce the passing of life member Harold Goldsack on April 25th. Our sympathies to his family.

Harold was born in East Bengal, India on 27th June 1908. He once told how he could remember epiphytic orchids blooming outside the bedroom window of his childhood home.

His family moved to Adelaide in 1916 and he attended Princes College as a boarding student.

He was introduced to South Australian orchids in bushland adjacent his family’s orchard at Coromandel Valley using Rogers “Introduction to the Study of South Australian Orchids” to identify these. Harold in 1924 introduced himself to Dr Rogers and they became good friends. Harold soon began to find orchids that were new to Dr Rogers and this fired his enthusiasm so that he began a serious study of our orchid flora.

One day in 1928 on a visit to Dr Rogers, Harold was shown the very first collection of the underground orchid Rhizanthella gardeneri. This was to be the subject of the last article Harold wrote over 50 years later.

With the passing of Dr Rogers in 1942 Harold became the foremost authority on South Australian orchids corresponding regularly with H M R Rupp, W H Nicholls and A W Dockrill. His extensive collection of pressed orchids was donated to the State Herbarium in 1978.

Harold wrote many articles on orchids his best known being “Common Orchids of South Australia” which appeared in the S Aust Naturalist in June 1944 and was used in “National Parks and Wild Life Reserves” book from 1965-1970. Harold also revised the orchid section of Black’s “Flora S Australia” in 1943.

Besides drawing and photographing the S Aust orchids Harold developed a large personal Orchid Library and cultivated many Australian orchids which he displayed at shows including our NOSSA shows. The first registered Pterostylis hybrid Ptst. Cutie was made by Harold and the name given to the original clone now grown by hundreds of orchid lovers is “Harolds Pride!”

His main interest was to enthuse others to see the beauty and value of our native orchids through his articles and the many illustrated talks he gave to natural history groups.

Harold was a member of the Royal Society of S Australia.

He was a Foundation Member of the Australian Native Orchid Society. (ANOS)

Ever ready for a challenge Harold at age 64 began studying for his Engineering and Surveying Certificate gaining distinctions in Maths, then working on the surveying of the S E Freeway.

Harold Goldsack’s name is commemorated in the South Australian endemic orchid Prasophyllum goldsackii, a fitting tribute to a true orchid lover.

R Bates

53KB Prasaphyllum goldsackii

Prasophyllum goldsackii – Photographer Ken Bayley

Bibliography of Papers by Harold Goldsack

Orchids of Coromandel Valley – SA Naturalist XIV, Nov 1932 PP 12 – 15

Notes on Caladenia Catifolia – R Br SA Naturalist XV, March 1934, pp 59 – 63

National Park of South Australia – Field Naturalists Sect. of Royal Soc of SA 1936, Being Vol XVII, Nos 1 to 4 of SA Naturalist pp 52 – 54 Orchids

Common Orchids of South Australia – SA Naturalist XXII June 1944 PP 1 – 12 with line drawings of 52 species

New Orchid Records for South Australia – SA Naturalist XXII June 1944, p 13

National Park and Reserves – Commissioners of the National Park, Sept 1956 pp 59 – 79 with line drawings of 52 species of Orchids, p 195 Distribution and flowering times of orchids in the National Park and Reserves

SA National Parks and Wild Life Reserves – Commissioners of the National Park and Wild Life Reserves, March 1964, pp 46 – 64 Orchids with line drawings of 52 species, pp 189 – 199. Distribution and Flowering times of Orchids in the National Park and Reserves

Orchids of the National Park and Wild Life Reserves – Reprinted 1965 by Field Naturalists Society, if (sic) SA from “SA National Parks and Wild Life Reserves” with permission of the Commissioners of the National Park and Wild Life Reserves

Blacks’ Flora of South Australia – Revised edition of p1, 1946 Assisted Rev H M R Rupp and W H Nicholls with the revision of the Orchidacea

Pollination of Caladenia deformis R Br – R S Rogers transactions of Royal Society of SA Volume LV Oct 1931 The pollination of Caladenia deformis as observed by H G was written up by Dr R S Rogers in an article for the Royal Society of SA

Rhizanthella gardnerii R S Rogers – The Orchadian p 113 Sept 1979 A note about the discovery of this orchid

Following is the article by Harold Goldsack referred to by Bob Bates in Harold’s obituary. Though he wrote for other publications, this was appears to be the only one in the NOSSA Journals.

Journal 1979 Volume 3 No 8 August

RHIZANTHELLA GARDNERI Rogers                              Harold Goldsack

Corrigin, Shackleton, Goomalling, Munglingup. Western Australia.

A new locality where the subterranean orchid Rhizanthelle gardneri Rogers has been found, as noted by Don Voigt in his letter to Roy Hargreaves to brings with it hope that after 50 years the secret life of the remarkable orchid may be unveiled. It also brings back memories of my first encounter with this plant.

As a young orchid enthusiast I had been collecting for, and writing to, Dr R.S. Rogers of Adelaide, who, at that time, was an extremely busy public personality. To my surprise, one day in 1928 I received a note from Dr Rogers inviting me to call at his house in Hutt Street after surgery hours as he had something to show me which he was sure would be of interest.

Naturally, I took the first opportunity to visit the Doctor, whereon he brought into the room a large jar with some white vegetable pickled in it. With a smile he said “Have you ever seen anything like this before?”

Well, there it was – this unique subterranean orchid from Corrigin, Western Australia, sent over by Mr C A Gardiner, the Government Botanist of Perth, who had realised the importance of this discovery.

The first plants were found in an area of virgin lane that had been rolled, burnt and then ploughed, which operation uncovered the white underground rhizomes. Mr John Trott, the discoverer, was puzzled by this strange plant growing around the stumps of Melaleuca uncinata R Br, common in the area, and sent it to Mr C A Gardiner. He, realizing the orchidaceous nature of the plant, visited the area, made personal observations and then sent a specimen to Dr Rogers for study, which led to the description of a now sub-tribe, genus and species of orchid – Rhizanthella gardneri Rogers.

Soon after this the Field Naturalists Society were to hold their Wild Flower Show in the Adelaide Town hall and attempted to have this unique specimen displayed there. However, the plant was too valuable to risk and an artist – Mr Lyall Lush – made a black and white drawings which was exhibited instead.

Within three years, on the east coast of Australia at Bulahdelah, another subterranean orchid Cryptanthemis slateri Rupp was unearthed. Unearthed is the word, for this one was unearthed by Mr Slater who was digging up rhizomes of Dipodium punctatum, the “Wild Hyacinth”, to attempt to grow them. All plants of the new orchid were found growing in association Dipodium. The importance of this find was such that Rev H I R Rupp was given a grant to travel to Bulahdelah to make further studies. This second find aroused worldwide interest and a German botanist suggested that the flowers of Cryptanthemis slateri were underground spikes of Dipodium. The morphology of the flowers soon disproved that theory.

Regarding this orchid, which Rupp named in 1932, Dr Rogers commented to me that he was sure that Rev Rupp’s parishioners must have had a very brief sermon the week Rupp received the first specimen of Cryptanthemis!

Dr Rogers then lamented that the orchid hunter has to add a plough and a pick to his orchid collecting equipment!!