Category: Growing Terrestrials

Where Have All the Growers Gone?


The following article is the longer version of the summary that will appear in the September 2021 NOSSA Journal. John Eaton, the NOSSA Speaker Co-ordinaor, has written passionately on his summary of Les Nesbitt’s talk given at the August General meeting. He completes his summary with an echo of Les’ appeal for the next generation of orchid growers whose expertise is so necessary for the continuting conservation of our unique orchids.


In one of NOSSA’s most significant and challenging meetings for many years, members were treated to a talk by our Patron, Les Nesbitt – whimsically titled – “Where have all the Growers Gone?” – after the 1955 Pete Seeger song-lament. Les integrated our NOSSA history into his talk.

Les was a founding member of NOSSA which was formed on 22nd March, 1977 – 44 years ago, with 44 very keen members. NOSSA membership had grown to 100 members by the year’s end.

The fledgling Native Orchid Society of SA first met at “Goody Tech” alias Goodwood Boys Technical High School. From then on – it was “All Go!” in those early years.

NOSSA’s second meeting soon saw the formation of the Seed Bank where new members were given Ptst. curta tubers from Roy Hargreave’s wash trough.

Our first three orchid displays – between 1978-1980 – were held in conjunction with the South Coast Orchid Club at Marion. The first (judged) NOSSA Show was held in 1981 – in the Supper Room at the September monthly meeting. By the following year (1982) it had expanded into the first NOSSA Public Show –held at The Orphanage, Goodwood.

The aims of the Public Show were four-fold

  • To educate the public
  • To raise Society funds
  • To exhibit members plants
  • To obtain new members

Over one thousand people attended this first public show! – almost ten times the number we would expect nowadays.

In 1983, these NOSSA Public Orchid Shows moved to The St Peters Town Hall where they remained for many years until the venue became too expensive.

Native Orchid “Rescue Digs” to preserve native orchid species threatened by development, occurred throughout the 80’s & 90’s. Les regarded these as the “golden years” for Native Orchid growers which continued until 1996 – the year that NOSSA sponsored the Australian Native Orchid Society (ANOS) Conference at Flinders University.

Thereafter the Shows were transferred to St Bernadette’s where they remained until 2019. Les then presented some pictures of these Native Orchid exhibits and pots from previous years and from the SAROC Fairs of 2017-2019 and 2021.

Les outlined NOSSA’s many efforts to create a new cohort of growers amongst members. Early members were growers, exhibitors, bushwalkers & photographers. However our current membership seems less interested in growing and exhibiting, preferring to focus instead on recording native orchids in the field – during bushwalking.

Les stressed the importance of growing in the preservation of indigenous native orchid species, especially as we face climate change. He then threw members a challenge, stressing the importance of growing native orchids to ensure their preservation in the hard years ahead – for all things green!

To support would-be growers, he referred members to some valuable references – such as NOSSA’s Green 1985 handbook: “Native Orchids of South Australia” – an invaluable guide to members interested in growing Native Orchids. There are also numerous articles on orchid culture in the early NOSSA Journals.

Lamentably, the emphasis nowadays is more on photographing and recording terrestrial native orchids in the field.

Les also mentioned the Tuber Bank, successfully run by Jane Higgs until severe frosts killed her orchids. Sadly, there are no members prepared to organise it now.

Les also mentioned other significant initiatives such as the New Members’ Group that met before General meetings, the 2016 “Flagship Orchids” 1-day orchid workshop initiative of the Australian Association of Bush Regenerators – in creating orchid-enhanced habitats.

Les also mentioned the $2.00 seedling plant-growing competitions with annual recalls until the first plant flowerings and the 2016 and 2017 Seed kits for the culture of – (mycorrhizal) fungus-dependent terrestrial orchids. These included detailed growing instructions –still available to those willing to “give growing a go!”

Notwithstanding the Covid-19 challenges, there were the most recent propagation initiatives of 2020-2021.

In a recent talk, Robert Lawrence has described the importance of indigenous native orchids as an indicator species of a healthy bushland. If we don’t respond to the challenges Les has thrown out to our membership – it may be a matter of “Where have all the orchids gone – long time passing”! There won’t be any orchids left for us to photograph. So it’s really up to us!

Who’s prepared to step up to the challenge?

I’m rapidly approaching 80! It’s too late for me to build space-demanding infrastructure such as a temperature-regulated shade-house/green-house and benching tables. But I do want to “step up to the plate” as a native orchid mini grower! I believe that the years ahead will be challenging ones for anything green, including me! Les reminded us that our common terrestrial are most at threat as the seedbanks of researchers tend to focus on the rare and endangered terrestrials.

Les’s talk has challenged me to establish a local (indigenous) terrestrial orchid presence in my native garden – where I’ve already got a burgeoning population of Microtis – dumped accidently in one of the loads of woodchips that replaced my lawn – 30 years ago. I’m hoping this indicates the presence of sufficient mycorrhizae to help me to establish some of the common greenhoods that Les said were most at threat from climate change. And hopefully, they will keep the microtis company! Dr Teresa Lebel, a speaker I’ve scheduled for March 22nd, 2022 is a fungi expert.

I hope Les’s talk – or if you missed it – this inadequate account of it – will challenge you, also – to become a mini-grower. As Henry Schoenheimer once said of our finite, depleting – and depleted – planet – in his book of the same name – “Small is Beautiful”!

John Eaton, NOSSA Speaker Coordinator, 28/08/2021

NOSSA: The Doco

Last year, UniSA second year media students were required to produce a short documentary about a local organised. Three of their students, Vanessa Rossi, Tayla Elliot and Emma Sullivan, chose to produce a video about the work of the Native Orchid Society of South Australia. And for this we thank them. It was interesting working with them and they learnt a few things about our bush gems – namely that they are not big and showy!

Some adjustment needed to be made to the original video, but it is now available for viewing

Terrestrial Culture – December & January

The following two articles are from the December 2019 NOSSA Journal. Written by Les Nesbitt, they cover the months of December and January.

Terrestrial Culture – December

A few late orchids such as Diuris drummondii may still have green leaves and flowers so will need watering every couple of days. Most terrestrials will have died down by now on the Adelaide Plain. Watering consists of a quick squirt with the hose once a week to moisten the top 1 cm to prevent tubers shrivelling. A small terrestrial collection of pots can be moved to a cooler place out of direct sun under a bench or to the south side of the house. A large collection must stay on the benches so extra shadecloth is added for the summer.

Repotting is in full swing now. Keep a stock of the required materials on hand including sand, soil, native potting mix, clay, blood & bone, chopped sheoak needles, smashed and sieved gum leaves pots labels, shadecloth squares for crocking, pencils to write on plastic, sieve and bowl, watering can & shadehouse benching. A system for washing and sterilizing pots before reuse is essential to control disease and virus.

Pots dry out quickly in hot windy weather. Water a day or two before repotting so that the potting mix is just moist. If too dry dust will be a problem and tubers can be damaged by hard lumps of mix. Too wet and the mix sticks to the tubers and clogs the sieve. The ideal is a mix that is easy to work when separating wet pots take tubers from mix. It helps to move some pots under cover in case of rain. Wet pots take several days to dry out which can hold up repotting. Alternatively, a sheet of plastic over the pots when rain is forecast will shed the water but remember to weigh it down with bricks or it will blow away.

Pick out the tubers and put them in a kitchen sieve sitting in a container of water. Use a jet of water to wash the tubers clean and spread them on a towel to dry. Discard any tubers that are soft or have turned black. If the tubers are healthy, firm and a pale colour the mix can be reused. Colony type tubers should have at least doubled in number since last year. Add half fresh mix to the old mix and add a big pinch of blood & bone fertilizer. Should the old mix be dark in colour, or the tubers not be healthy looking then throw out the old mix and pot up in new mix.

Select the pot size, place a shadecloth square in the pot to retain the mix when it dries out. Fill the pot with mix to about 2cm from the top. Select the largest tubers for a show pot and push them into the mix with the shoot on top. The small tubers can be potted in another pot to grow bigger next year. Cover the tubers with more mix and almost fill the pot. Firm the mix down with your hand or use the bottom of an empty pot. Cover the surface with chopped sheoak needles. Write out a label with the name of the orchid and the provenance,
if known. On the back of the label note the number of tubers and the date planted. Water the pot gently so as to not disturb the needles. This helps settle the soil around the tubers and makes subsequent watering easier. Put the finished pots back in the shadehouse to await the next growing season.

Send off your tuber bank order before Christmas or you might miss out on your choices. The tuber bank is a great way to increase your terrestrial collection.*

*Tubers are sold only to financial members

Terrestrial Culture – January

Start watering the blue tag pots in January. Pots of orchids from the East Coast of Australia where it rains in Summer are given a blue tag as the culture is different compared to local terrestrial orchids. This early shooting group includes most cauline greenhoods, Pterostylis baptistii and Corybas hispidus. Local South Australian tubers can be kept completely dry until at least mid-February if pots are shaded.

When your tuber bank order arrives, pot up the tubers straight away. Plant each species in a separate 125mm or 150mm pot. Don’t forget to record the provenance name (if known) on the label and in your recording system. The
provenance is the location of the original collection. Provenance is important because in 10 years the orchid will possibly be extinct in that area as suburbia expands or weeds take over the habitat.

Summer watering is important. Too little and tubers may dry up. Too much and they may rot or come up early before the heat of summer is over when they will be attacked by thrip and aphids. A light sprinkle on top of the pots once a
week works OK.

Try to finish repotting this month. If left until February there is more chance of breaking off the new shoots which can be well developed by late February.

Terrestrial Culture – November

Though a bit behind time, but for completeness, Les Nesbitt’s culture notes for November 2019 from the November 2019 NOSSA Journal are reproduced below.

After the first week in November, pots dry quickly and it is hard to keep pots moist. Water green leaves, let the others dry off as plants die down. Late species in flower this month are Diuris drummondii, rufa group Pterosylis & Microtis. Seed pods ripen quickly now, so check every couple of days.

Repotting can start at month’s end although Dec – Jan is the ideal time if there are only a few pots needing to be done. Repot orchids with large tubers first as they are more prone to rotting if there is prolonged hot wet weather this month. We usually get at least one thunderstorm before Xmas. Until the old tuber has completely dried up it can go mouldy and infect the new tuber alongside. This especially applies to the slow multipliers such as Diuris and Thelymitra that have large tubers.

Gather potting mix materials and pots ready for the summer activities as this growing season comes to an end.

TYPES OF POTTING MIXES

Terrestrial growers all have their favourite mix that works for them. Some recipes are:

~ Half premium native potting mix and half sand.
~ Sand, buzzer chips, mountain soil (see ANOS cultivation booklet).
~ 50% sand, 20% Hills soil, 30% organic matter ( seed & cutting mix, native potting mix, smashed gum leaves).
~ Eco terrestrial mix (fine composted pine bark) and perlite.

Some species require adjustments to the mix for optiumum results. Caladenia like more sand, Diuris & Pt nutans 30% clay, Acianthus pusillus more organic matter. The mix must be free draining in Winter yet retain moisture in Autumn and Spring. Most growers reuse some of the old mix, (up to 50%) to which new ingredients are added at repotting time. The reason for this is to carry over any fungus in the old mix. Add a little blood & bone fertilizer and native slow release pellets. Most of the orchids in cultivation prefer a slightly acid soil mix.

Locate a source of Casuarina trees in your area and collect the fallen needles. These trees grow all over Adelaide. Chop the needles into lengths of 1 – 5 cms and store in a dry place.

POTS

The ideal size pots for terrestrials seem to be 125mm & 150mm standard pots that are about 150mm deep. Smaller diameter pots dry out quickly and it is difficult to keep the mix moist in Spring. Shallow clay pans can be used for specimen show pots.

November is a good month to flask seed of Diuris for planting out next autumn. Terrestrial seed can be sown in flasks at any time of year but some months are better than others to match tuber development in flask with optimal deflasking in April.

September Terrestrial Orchid Culture Notes

Continuing Les Nesbitt’s notes from the NOSSA Journal, this month he reminds us that not only is it a busy month but it is the month of the NOSSA Spring Show.

September is the busiest month of the year in the terrestrial house. apart from orchid shows every weekend there are numerous tasks to perform. The days are getting longer at a rapid rate. Day length increases by 2 hours in the 6 weeks from the 1st Deptember. Equinox is about the 21st September.

Early Spring weather is changeable from cold, windy & wet to warm & sunny. Give plants as much sun as possible as new tubers are developing rapidly. Hand watering may be necessary if there is no rain so get the hose out of winter storage. Do not let the post dry out this month. There are lots of flowers everywehere. Take photos as some flowers are fleeting and may only last one day. Different pollinators are about for the more colourful terrestrials that start flowering in spring.

Prepare your flowering plants for the NOSSA Spring Show. It is fun to put in a display even if you only have one or two plants. You learn a lot from other growers. We certainly need new exhibitors each year. Seek new species to add to your collection at the NOSSA Spring Show. Be there at 10am Saturday morning for the hard to get species which are always in short supply.

Spring is an ideal deflasking period but get it done in the first 2 weeks to give sufficient growing time to harden the plants and for tiny seedling tubers to form before the summer dormancy.

Notes on Tuber Removal

Start tuber removal after the middle of the month. In a wet year you may have to move pots under cover a week earlier to dry out a bit before knocking them out. working with mud is a real pain and not recommended. Use this method to propagate the slow multiplying terrestrials that are amenable. those recommended for slow multiplying are Diuris (punctata & behrii), and rufa group Pterostylis (cycnocephala & biseta).

Knock out the pot and carefully remove most of the soil from the plant. Find the new tuber which is usually whiter smoother than the old tuber. Hold the junction of the old tuber and plant stem firmly with one hand and grasp the new tuber with thumb & finger of the other hand. Twist & pull the new tuber which will separate from the plant. If the old tuber and leaves break apart you have stuffed up. Repot the plant & old tuber and water the pot. The new tuber can be buried in the same pot or potted up separately in another pot. Keep the plant watered for at least six weeks or as long as the leaves stay green. The plant may form one or two small new tubers before going dormant. In January you can repot and see how well the method worked.

Monthly Terrestrial Orchid Culture – August

With Spring on the way, things are starting to change in the Orchid House. Here are Les Nesbitt’ notes from the August Journal 2019 Vol 43 No 7

Terrestrial Culture – August

The days are getting longer now, noticeably so after the middle of the month. When the clouds clear, the sun is stronger & higher in the sky. Temperatures increase and growth speeds up. Lots of buds are developing so there is plenty to see in the orchid house. The greenhoods are a feature with Pterostylis curta, nutans, pedunculata and their hybrids are all flowering.

Pests become more active. Look out for aphids on flower stems. Depending on the season deflasking can start after the middle of the month if a sunny and dry Spring is forecast, otherwise wait until September.

The NOSSA Spring show is only a month away. Start preparing your specimen pots for the display. Any spare pots can be sold on the trading table. There are never enough terrestrials on the trading table at the show to meet the demand.

Photograph your orchids when the flowers are at peak condition. Then hand pollinate a flower or two to get seed for the NOSSA Propagation Workshop or for sowing around mother plants next autumn. Prepare two pots of each species, one for showing and one for seed.

 

How to hand pollinate.

Look closely at the flower column to see the positions of the pollen and the stigmatic surface. Flowers can be self-pollinated if there is only one. Fatter pods with more viable seeds result if two plants of the same species are cross pollinated. That is transfer the pollen from one flower to a flower on another plant. Cross pollination mixes the gene pool to prevent inbreeding. Use a toothpick or a she-oak needle to touch the pollen which will stick to the wood. Wipe the pollen across the stigmatic surface of the other flower and the job is done.

If pollination is successful, the flower will collapse in a few days and the ovary will start to swell. For greenhoods the stigmatic surface is halfway up the front of the column. Remove the front of the flower and the lip so you can see what you are doing. Greenhoods have yellow pollen. For Diuris and Thelymitra the white pollen is hidden behind the sticky stigma. Caladenia have yellow pollen under flaps at the top of the column. Stroke upwards to open the flaps as would an insect backing out of the flower. The stigma is a hollow sticky depression just below the pollen. You will have to tip the flower right back to see it.

Monthly Terrestrial Orchid Culture – July

Continuing Les Nesbitt’s articles from the NOSSA Journal, this month’s (Vol 43 No 6 July 2019) is a relaxing time.

Midwinter is cold and cloudy most days. July is often the wettest month as well. A good time to sit by the heater and read orchid books or search the internet as you plan future activities. Tidy up your records and draw up a wanted list of terrestrials to purchase or swap. Activity in the lab continues with seed sowing and replating. Deflasking should wait until spring as tiny seedlings rot away if planted out in winter. Pots showing any signs of rot should be moved out of the
rain to dry off.

Not a lot to do in the orchid house except observe your orchids and watch for pests that are always looking for a feed. Growth will be slow. Give plants as much sunlight as possible. The very first seedling leaves may appear this month around mother plants. Give yourself a pat on the back if you see any seedlings. More may show in August & September.

Corybas flower this month and do not mind being cold and wet. Corybas flowers will shrivel up if the surrounding air is dry. Mist them daily or place a clear cover over the pot & the flowers will last for weeks. A tall plastic sleeve around the pot or an upturned glass bowl can be used.

Orchid clubs hold their Winter shows this month. Check them out for additions to your collection.

Monthly Terrestrial Orchid Culture – June

It’s June and the the orchids tubers are on the move. And yes there are some tasks for this month but as can be seen by Les Nesbitt’s notes in the June 2019 NOSSA Journal (Volume 43 N0 5) there is not a lot to do.

Diplodium robustum  (syn Pterostylis robusta) – one of the cauline greenhoods


June is cold, often with frosty mornings and sunny days. Terrestrials can take -20C but any colder results in permanent damage. If you live in the country, you may need a solid roof for frost protection. Frosts are rare these days in Adelaide. I have black rubbish bins full of water under the benching in my glasshouse to moderate the temperature. The bins absorb heat in the daytime and radiate it out at night. If it is not frosty it will be cold wet and cloudy. Growth will be slow and there are few flowers out. There is not a lot to do in the terrestrial house.

Pterostylis robusta and Acianthus pusillus flower this month. If there are no flowers this year, they probably aborted due to high temperatures or excessive dryness over summer/autumn. Try putting the pots under the bench in a cooler position next summer.

The last of the terrestrial orchid leaves should appear this month although there are always a few stragglers. Tubers that formed in the bottom of a pot have a long way to grow to reach the surface. Sometimes they come out the drainage holes. If no plants appear, do not throw the pot away. Sometimes orchids take a year off and send up a leaf the following year. They are capable of forming a new tuber from the old without making a leaf. Gather together the “empty” pots in a corner. They can be left for another year or you can knock them out next month to try to establish what can be improved. Most weeds have germinated by now so weeding gets easier.

It is hard to drag yourself away from the heater this month but at least once a week go out on a wet night with a torch and examine your orchids for slugs, snails, earwigs, cockroaches, grubs and beetles. They always feed on your best orchid buds.

The SAROC Fair is in June. Clean up your flowering pots for the NOSSA stand. Other orchid clubs hold winter shows in June & July. Go along and see if there are any interesting terrestrials on the trading table.

Monthly Terrestrial Orchid Culture – May

The following article by Les Nesbitt is taken from the Native Orchid Society of South Australia Journal, May 2019, Volume 43 No 4. The article has been slightly modified with editorial changes in black.

The majority of terrestrials will have leaves showing by month’s end. A few stragglers like South Australian Corybas and Western Australian Cyrtostylis huegelii will not appear until June so do not panic yet.

Pterostylis truncata (little dumpy) flowers this month with a large flower on a short stem. This species is given a blue tag to denote watering from January otherwise there will be no flowers under Adelaide conditions.

Tasks for May

  • Move the Autumn flowering greenhoods under cover as the flowers open because they generally have tall thin stems that will bend over under the weight of rain drops on the flowers.
  • Rot can be a serious problem in May. Do not overwater if there is little rain; and inspect plants closely and often. The rot can be on the leaves or below ground. Look for plants that are not thriving and give them a gentle tug to see if there are any
  • Move infected plants away from healthy plants to a hospital area under cover. Water from below by standing the pot in a saucer of water. Keep the leaves dry. Good air movement and at least 5 hours sunlight a day are essential for the next 3 months.
  • The fast multiplying orchids will appreciate a weak dose of liquid fertilizer once a month until spring.
  • Weeding is a chore this month as weed seeds germinate after rain. Pull them out while they are small maybe even with the help of tweezers.

Virus

Inspect plants closely for virus as the symptoms show in the emerging leaves. All plants can be infected with viruses of which there are many. There is no cure for virus. Infected plants must be destroyed to prevent virus spreading to healthy plants via sap sucking insects or human activities spreading sap. Infection during the growing season does not show up in the leaves until the following year. It is difficult to eliminate virus entirely hence the need to be vigilant.

Signs of Infection

  • Virused Pterostylis leaves may have light & dark green blotches or be thicker than normal and look crippled or turned up at the edges.
  • Another sign to look for are pointed pimples on Caladenia and Pterostylis
  • Virus is harder to spot on the narrow leaves of Diuris and Thelymitra. Healthy leaves are straight with almost parallel sides. Leaves that have kinks or are curved probably have a virus. Variegated blotching may be present in severe cases.

Managing

  • If only one or two plants, in a community-pot, show symptoms they can be lifted out soon after the leaves appear and before side stolons form.
    • A tool can be made from wire to do this. Bend a foot on the bottom of the wire and a loop handle on the other end.
    • Push the foot into the mix alongside the infected plant, rotate the foot under the tuber and lift the plant out.
  • At potting time (when tubers are dormant)
    • A sieve is a great time saver during repotting but at the same time an excellent way to spread virus.
    • Do not shake the sieve when tubers are present.
    • Pick out the tubers as you see them and drop them into a smaller kitchen sieve sitting in an ice-cream container of water. The sand and dirt wash off and falls through leaving clean tubers behind.
    • Use a jet of water to remove any remaining dirt.
    • Pat the lumps of mix in the big sieve to crush them to expose any tubers.
    • Shaking the sieve is the equivalent of sandpapering the tubers, a sure way to spread virus.
  • If several plants are virused it is better to dump the whole pot, soil and all.
  • Refuse new plants that look suspect.

ALL EFFORTS SHOULD BE MADE TO ELIMINATE VIRUS FROM AN ORCHID COLLECTION.

Pterostylis 'Nodding Grace'

Monthly Terrestrial Orchid Culture – April

The following article by Les Nesbitt is taken from the Native Orchid Society of South Australia Journal, April 2019, Volume 43 No 3

Terrestrial Culture – April
Les Nesbitt

The days and nights are cooling down, evaporation rates are dropping and pots take longer to dry out so decrease the watering. If in doubt wait another day before watering. Regular rain usually begins around Anzac Day. There is nothing like a good rain to make terrestrial leaves pop up almost overnight. A few early flowers are out this month – Eriochilus species and possibly Pterostylis truncata. Keep up the pest control and pull out weeds while they are still small.

Sow seed on pots around mother plants of fungus dependent orchids this month. Mix seed & fine sand together to avoid wasting precious seed. A pepper shaker helps spread the seed evenly. Water gently to wash the seed into the mulch.

April is a good month to deflask terrestrials. Seedlings need to establish & harden up before winter so get deflasking completed by the end of April. Check out flask suppliers for that special species. The next deflasking opportunity is early spring.

Deflasking Terrestrial orchids

Prepare a suitable soil mix for the orchid to be deflasked along with labels & sheoak topping. Use the same mix as for adult plants.

Select a flask with strongly growing seedlings, preferably with small tubers but plants without tubers are OK. Remove the flask lid and tip the mass of plants and agar into a fine sieve. If you are nervous remove clumps of plants from the flask with tongs. Try to minimize breakages. The junction of leaf & tuber is very weak. Over a sink or lawn, use a jet of water to wash away the agar leaving clean seedlings behind.

Fill a pot with mix to within 2 cm of the rim and tamp down. Select small clumps of seedlings and stand them around the edge of the pot. Insert a label with the appropriate info as this pot will not be repotted for 2 years. Pour a handful of mix into the centre of the pot and gently squeeze mix out around the seedlings just covering the bases but not burying the leaves. Add more mix if necessary. Tamp down the mix in the centre of the pot. Add a layer of chopped sheoak needles. Water gently to settle the mix around the seedlings.

The pot can go into the shadehouse with other terrestrial pots although it helps to keep all the seedling pots together in a sunny place with good air movement. Ensure the pot does not dry out. If kept too wet the seedlings may rot. If the seedlings establish and grow strongly they can remain in the shadehouse over winter. At any sign of rot move the pots out of the rain under cover and water by standing the pot in a saucer of water.

Next dormant season as soon as the leaves have died down, add more mix to completely fill the pot. This helps to protect the tiny seedling tubers from drying up in the heat of summer. After the second growing season the tubers should all be large enough to find easily at repotting time.

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