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

Gleanings from the Journals: Terrestrial Potting Mixes

The following article by Les Nesbitt was published in May 2017 Native Orchid Society of South Australia Journal Volume 41 No 4. The article relates to Australian Native Orchids.

Suggested potting mixes for potted native terrestrial orchids have changed greatly over the years as some ingredients such as peat moss have become too expensive or difficult to obtain. Basic requirements are that the mix should be free draining yet retain moisture and should have an organic component that breaks down slowly and does not go mushy in winter. Most species are not too fussy and will grow in a variety of mixes.

Those tubers that desiccate in summer do better in a heavy mix that contains clay. Examples are Diurus behrii, D. punctata and Pterostylis nutans.

Tubers that rot easily in wet soil in Spring prefer an open coarse sandy mix. An example is Thelymitra antennifera.

A dry mix containing a higher proportion of sand is usually recommended for Caladenia and Glossodia species grown in pots. In contrast these orchids grow in clay soil on my property in the Adelaide Hills but there excess water can run off. In pots, excess water has to drain through the potting mix.

An organic component is vital to feed orchid fungi.

Some Basic Ingredients:

  • Washed sand with rounded particles. (Not sharp sand as this sets hard in summer.)
  • Soil (sandy loam, clay based loam, mountain soil)
  • Native seedling mix (Bark based – sieve to remove splinters)
  • Native potting mix (can be sieve* to remove larger particles)
  • Chopped and sieved* gum leaves
  • Perlite or isolite (but will make tubers harder to identify at repotting time)
  • Composted leaf mould & buzzer chips (but needs to be gathered now for use next summer)
  • Cauarina (She-oak) needles chopped for surface mulch

Some Suggested Potting Mixes

  1. ANOS-Vic dry mix – 2 parts coarse sand, 1 part coastal sandy loam, 1 part composted buzzer chips, 1 part leaf mould
  2. 100% native potting mix. (Works for drought resistant tubers, viz. Pterostylis curta & P. pedunculata)
  3. Native potting mix (sieved*) and isolite
  4. Native potting mix and sand
  5. Les Nesbitt’s current mix of 50% sand, 20% hills soil, 25% seedling potting mix (sieved), and 5% chopped & sieved* string bark gum leaves.
  6. Dry mix, 50% coarse sand, 25% perlite & 25% native potting mix
  7. Heavy mix, 50% clay soil, 30% sand and 20% organic matter

* Use a 5mm sieve

thelymitra-plants-1.jpg

Thelymitra in cultivation

Watering When: cauline type Pterostylis

A common question asked is when to water terrestrials. The short answer is to keep them dry over summer but there are variations such as was previously posted about the watering regime for Chiloglottis. In the March 2017 NOSSA Journal, Les Nesbitt’s article highlights another watering variation.

Blue Tags

Les Nesbitt

Jane Higgs’ lovely pot of the red form of Pterostylis coccina in flower had a blue tag. Jane explained that a blue tag meant that watering had to commence in January for that pot and not at the end of February as is normal for most terrestrials. Start watering later and there will be no flowers. Her pots are under a solid roof. She explained that in the ANOS Vic cultural booklet (Cultivation of Australian Native Orchids) there is a list of cauline type greenhoods which she tags with blue, and includes Pterostylis decurva, aestiva, laxa, coccina, revoluta, reflexa, truncata, robusta, alata, and fischii. To this list can be added abrupta and also the rosette types ophioglossa and baptistii which shoot early.

I have trouble growing and flowering this group of Autumn flowering greenhoods. I went home and dragged out my ANOS Vic booklet and brushed up on the notes. I found several old blue labels in the shed and cut them into strips. I now have blue labels in my pots and the pots are grouped together in the shadehouse where they get afternoon shade. They were given a thorough watering but it will be too late to expect flowers this year. I find large tubers of this group rot easily in Spring and the plants go dormant earlier than other greenhoods. I will try to remember to move the pots under cover in September to let them dry off.

Diplodium in cultivation

Diplodium robustum – one of the cauline greenhoods

Having a visual reminder would certainly make it easier to know when and which pots to water. Obviously other coloured tags can be used instead of blue, so long as they stand out from the label.

 

2017 February Winning Picture

1702 sm CC Cryptostylis subulata

The first competition for the year followed a wet orchid theme with three of the orchids being South Australian swamp orchids and the fourth from Western Australia; though not a swamp dweller, it grows in shallow moist soil.

The outstanding winner was Claire Chesson’s Cryptostylis subulata, followed by Robert Lawrence’s Spiranthes alticola, Rosalie Lawrence’s Pterostylis falcata and Pauline Meyer’s Thelymitra villosa.

Known to South Australian’s as the Moose Orchid, elsewhere it is either Large Tongue Orchid or Cow Orchid. This tall (40 to 110 cms) evergreen orchid is common in the eastern states where it is commonly found in damp areas as well as swamps. but in South Australia it is limited to swamps and is rated as endangered.

Leo Davis makes some interesting observations about the structure of this flower in his article Upside Upside Down which is well worth reading (https://nossa.org.au/2017/03/03/upside-upsisdedown/).

Whilst not an easy orchid to grow it has been cultivated although seed set has not always occurred. Helen Richards, an experienced Victorian terrestrial orchid grower, shared in an email how she grows them.

Cryptostylis species grow from brittle rhizomes which can be quite long and they resent frequent disturbance. Mine are potted into a pot therefore that is large enough for the long roots and which will accommodate further growth for several years. My mix is ANOS basic mix, the same as I use for Pterostylis and many other genera. They need to be kept moist all year round, especially in summer when they flower and new leaves appear, their active growing period. I grow them in an area of moderate light. Others have seen pollinators active on the flowers but I haven’t. However seed capsules frequently develop without my assistance with a toothpick. Richard Thomson says they haven’t had success germinating the seed.”

Reference

https://nossa.org.au/2017/03/03/upside-upsisdedown/

http://bie.ala.org.au/species/http://id.biodiversity.org.au/name/apni/89052

http://saseedbank.com.au/species_information.php?rid=1288

Personal communications Helen Richards (OAM), Chairman Australian Orchid Foundation

Bates, R. J., ed. (2011). South Australian Native Orchids. Electronic version, 2011. NOSSA

The other entries :

1702 sm RWL Spiranthes alticola

1702 sm RAL Pterostylis falcata

1702 sm PM Thelymitra villosa

Q&A: How do I deal with mould in my orchid flasks?

Question:

I have recently been learning about propagating orchid via flasks but I have mould in some of the flasks.

Orchid Seeds in flask with mould

Flask with orchid seeds and mould

There is mould in the flask with orchid seeds and also in the flask with Diuris tricolour in bulbs.  The bulbs are almost ready for deflasking.

Diuris tricolour in flask

Flask of Diuris tricolour (no mould) – these will be deflasked later this year.

 

What can I do?

Answer:

With a home laboratory, no matter how careful one is, mould can still contaminate the jars of agar. If mould occurs when the orchids are still in seed, then the whole jar needs to be discarded.  The seeds will not survive.

With the Diuris flask, as they are almost ready for deflasking, pot them out straight away. This needs to be done within 10 days of the mould appearing. The weather (March, 2017, South Australia) is still a little too warm but if left in the flask, the plants will die.  Potting them out may give them a chance of survival.

When deflasking, it is important to rinse all the agar off the bulbs before potting on as normal. Once potted, it could help to cover the pot with a cut down clear drink bottle with the lid removed. This will allow some air to circulate. Keep the pot in a shady spot.

Diuris tricolour in pot with bottle top cover

Potted Diuris tricolour with protecting bottle cover

Will it survive in the pot? Hopefully it might but at least the plants have a better chance of survival then if left in the flask where it would surely die.

 

WATERING WHEN – CHILOGLOTTIS

Though Melbourne and Adelaide conditions are very different, in cultivation the watering is similar with the warning that in Adelaide it is a harsher environment for this genus.

The following information has been kindly supplied by Richard Thomson, an experienced terrestrial grower from ANOS Victoria.

03 sm PM Chiloglottis valida

Chiloglottis valida

Generally, Chiloglottis are kept damper than Pterostylis, during the dormant period. As many Chiloglottis need the potting media and the tubers dampening in summer, the general action with water, is to have the tubers damp until leaves emerge. Then to commence normal pot watering.

Chiloglottis, can get infected with rust. The first thing usually noticed is some pairs of leaves sticking up in the air. When you look closely you will notice some whitish little lumps on the underside of the leaf. Please immediately take the pot away from your other orchids as it is contagious across Chiloglottis. There does not seem to be an effective way to treat the infection.

ANOS VICTORIA MEETINGS

CHILOGLOTTIS
Species State / Location Month Benched BUSH FLOWERING WATERING
chlorantha NSW July Aug Sept Sept to Oct Keep damper from early February. Water when leaves emerge
cornuta S NSW Vic Tas SA Nov Dec Nov to Feb – altitude Keep damp all year. Water when shoots emerge.
diphylla Qld NSW Feb Mar Apr May Jun Jul  Aug Feb to May mid to late January
sp affin diphylla Feb Keep damper from early February. Water when leaves emerge
formicifera NSW Jul Aug Sept Oct Nov Aug to Nov keep damper from early February, Water when leaves emerge
sp affin formicifera Jul Keep damper from early February. Water when leaves emerge
gammata Tas high Oct to Feb
jeanesii Vic Nov Dec Nov to Jan Keep damp all year. Water when shoots emerge.
longiclavata N Qld Feb Mar Apr May Jun Jul Aug April to June mid to late January
palachila N NSW Aug Sept Oct Nov Nov to Feb keep damper from early February, Water when leaves emerge
x pescottiana NSW ACT Vic Jun Jul Aug Sept Oct Aug to Nov keep damper from early February, Water when leaves emerge
platypetala Sept Keep damper from early February. Water when leaves emerge
platyptera N NSW Jul Aug Sept Oct July to Oct keep damper from early February, Water when leaves emerge
reflexa NSW Vic Tas Feb Mar Apr Dec to May mid January
sp affin reflexa Feb mid January
seminuda S NSW Feb Mar Apr May Jan to April keep damp all year
spyrnoides S Qld N NSW Feb Apr Dec Dec to April Keep damp all year. Water when shoots emerge.
sp affin spyrnoides Feb Oct Nov Dec Dec to Feb Keep damp all year. Water when shoots emerge.
sylvestris Qld NSW Feb Mar Apr May Jun Jul Aug Dec to May early to mid January
trapiziformis Qld to Tas Jul Aug Sept Oct Nov Aug to Nov keep damper from early February, Water when leaves emerge
triceretops Tas Oct Aug to Dec Keep damp all year. Water when shoots emerge.
trilabra NSW ACT Vic Feb May Dec Dec to March late December or earlier
trullata Qld Jul Aug Sept Oct Winter keep damper from early February, Water when leaves emerge
truncata S Qld Jun Jul Aug Sept Oct July to Sept Early to mid February
sp affin truncata Jul Aug Sept Autumn Keep damper from early February. Water when leaves emerge
vallida NSW ACT Vic Sept Oct Nov Sept to Jan – altitude Keep damp all year. Water when shoots emerge.

(As there is no January meeting, there is no information on flowering in cultivation for this month.)

From the chart, it can be seen that the cultivated flowering time does not always match the bush flowering time.

03 sm PM Chiloglottis valida

Chiloglottis valida

Growing Leek Orchids – Is it Possible?

The Native Orchid Society of SA has been involved with the Threatened Orchid Project which is attempting to propagate some of our most threatened orchids.  There has been some success such as Thelymitra epicaptoides (Metallic Sun Orchids) but others are proving elusive.  Marc Freestone, from the Orchid Conservation Project, Royal Botanic Gardens Victoria, is a PhD student who is researching one such difficult to grow orchid genus, the Prasophyllum.

Prasophyllum murfettii sm

Prasophyllum murfettii (Denzel’s Leek Orchid)

To assist with his research Marc has the sent the following request.

CAN ANYONE GROW LEEK ORCHIDS?

South Australia has about 40 species and Victoria about 74 species of the native Leek Orchids, Prasophyllum.  Some are on the brink of extinction.

A major problem hampering efforts to prevent our Leek Orchids from going extinct is that they have proven next to impossible to grow in cultivation.  They have proved extremely difficult, usually not germinating at all, or germinating but then dying soon after.  Occasionally some success has been had (particularly with symbiotic germination) but successful germination trials to our knowledge have so far proved un-repeatable.  Working out how to grow Prasophyllum is critical for the survival of many species at risk of extinction across southern Australia.

To try and change this, I will be studying Prasophyllum and their relationships with symbiotic mycorrhizal fungi.

But I need your help!

I am wanting to hear from as many people as possible who

  • have tried (either successfully or unsuccessfully) to grow Leek Orchids or the closely related Midge Orchids (Corunastylis).
  • have observed Leek Orchids (or Midge Orchids) recruiting from seed in the wild.

If you can help, or know of anyone who might be worth talking to, please contact me at: marc.freestone@rbg.vic.gov.au or 0428 304 299.

(Funding and support for this project: Australian National University, Federal Government National Environmental Science Programme, Royal Botanic Gardens Victoria, University of Tasmania).

I would encourage people to contact Marc with whatever information that you have, no matter how insignificant you may think it is.  Every little bit helps including unsuccessful attempts.

His eventual aim is to be able to work out how to grow them reliably from seed in cultivation.

Advice from the past – Start Watering

In 1984, G.J.Nieuwenhoven was the editor of the NOSSA Journal.  In February of that year he wrote the following:

Welcome back to NOSSA.

 After the holiday break we are all looking forward to the next meeting to talk about our favourite plants and renew friendships.

Several members have reported an early start to the terrestrial season with Pterostylis species, a couple of Diuris species popping up already.  For some of the eastern states Pterostylis of the cauline group this is normal, especially if you keep the pots cool during the summer (a cellar is ideal but underneath a shaded bench in the shadehouse will do nicely). Very light watering should take place when the first shoots appear but do not overdo the watering or place pots in the sun for we are sure to get some more hot weather yet and this could cook your plants before you know it.

The Diuris are really out of season but it was probably the rain in late December and early January that started them off, anyway, these too should be kept slightly damp if they are up.

If you have not finished repotting by now it would be best to leave it until next year as the new shoots which are already beginning to grow from the tubers are very easily broken off while sifting them from the soil.

Apart from that all you can do is wait for the rains to come in March and then start searching for plants to appear – and keep those fingers out of the pots or you may damage one of your best plants looking for the new growths.

This is also the time to start taking notes when plants first appear, etc.:

  • when they flower and how many flowers from a given number of tubers;
  • what kind of soil; what conditions (i.e. shaded or not, damp or dry).
  • Anything that may assist in years to come to help you understand and grow our orchids better and, more importantly, multiply them.
  • A card index system would be a good way to store information, otherwise an exercise book will do.

                                                            Editor

The timing of the article tallies with the advice that was recently given at the end of February – start watering the terrestrials now if you haven’t already begun.  Hopefully by the flowering time you will have a lovely display of terrestrials such as the Thelymitra, Arachnorchis and Caladenia featured below.

 

Pot of Thelymitra Kay Nesbitt Cultivar copyPot of Arachnorchis argocallaPot of Caladenia latifolia cultivated by Les Nesbitt

ABC Gardening – Terrestrial Orchids

Back in 2013, Gardening Australia of the ABC produced a video featuring Helen Richards, a Victorian who has in-depth knowledge of growing terrestrial orchids.  Though Helen lives interstate and adaptions do need to be made for different locations and conditions, this video of her shadehouse is very instructive for any South Australian’s wanting to grow their own terrestrials.

Click here to view the video and read the text.

Pot of Thelymitra Kay Nesbitt Cultivar copy

Pot of Thelymitra ‘Kay Nesbitt’ cultivar

Pot of Arachnorchis argocalla

Pot of Arachnorchis argocalla

Pot of Caladenia latifolia cultivated by Les Nesbitt

Pot of Caladenia latifolia