Svante Malmgren         Henric Nyström

Orchid propagation

Plants in the genus Orchis have recently been reorganized and some renamed by professor Richard Bateman in England. We continue to use to old nomenclature here, in order not to confuse conservative Scandinavian readers too much.

There are some wonderful species within these genera. Most Orchis species that grow in Sweden are just hardy on the Baltic Islands of Gotland and Öland where the winters are relatively mild. Orchis mascula grows in limestone areas in inland southern Sweden – but also very close to the coast in northern Norway. The Orchis species often have very specific habitat requirements and as a result do not always grow well in all gardens

In some parts of Europe, several Orchis species are very rare and under the threat of extinction. Local conservation projects that include artificial propagation are undergoing trials in some places, such as in England for Orchis militaris. Until now, such work has been limited by the difficulties associated with propagation techniques.

One should be very suspicious of offers of affordable, large flowering-sized Orchis plants from nurseries or the Internet. The plants are not commonly produced by artificial propagation and many are illegally traded and are sourced from wild sites like the Alps, where some species are locally common. There is still a problem in Sweden, too, where plant theft on a large scale for commercial purposes continues in Öland and Gotland. For example, on April 22 2005, police at the port of Visby on Gotland arrested two Danish men whose car turned out to be full of stolen plants, mainly different species of Orchis, but also Epipactis atrorubens. One of the men had been selling orchids regularily for several years “as his speciality” both openly and on the Internet. We hope that this has now come to an end.

We can propagate several, but not all, species within this group on a large scale and hope that with the help of collegues we will soon solve the problems that remain.

A very few species seem to germinate poorly (from mature seed) but our main problem with propagation, or rather growing on in soil, is the Swedish climate. Only Orchis mascula is truly hardy outdoors where we live. Keeping plants frost-free over the winter and growing them in a cool greenhouse in the spring can easily save other species, such as Orchis simia, purpurea, Spitzelii and morio. “Bordeline species”, such as O. militaris, however, greatly prefer mild Swedish winters to cool greenhouse.

Please, read the Ophrys page first! Ophrys are very easy to propagate from seed and can be seen as a “standard”, from which minor variations should be done to propagate Orchis/Anacamptis and close relatives.

When propagating Orchis from the Mediterranean area, some species tried so far, seem to behave just like the Mediterranean Ophrys and Serapias, with a rather quick development on medium, without any certain temperature requirements. Not so surprising.

Orchis/Anacamptis etc from Central Europe on the other hand, and some of those from the Mediterranean area, from our experience, strongly seem to benefit or even demand a cool treatment of 8-12 weeks at a certain size of protocorm development. This period is when the protocorm is 4-5 mm size and indicating the start of a shoot, but no root. Probably this corresponds to natural cycle with germination in early autumn, followed by a cool but usually frostfree winter. Several photos will illustrate this condition.

Possibly/probably different clones from different climate zones will behave and respond differently to temperature sequences. But the temperature sequence should be kept in mind if you have problems with Orchis/Anacamptis propagation.

Some species can well be grown without cool treatment – as Orchis morio – but as photos indicate, growth and tuber production seems much better if also plants in this species are given a cool period.

The length of the cool period seems to be 8-12 weeks. Temperature should be rather close to Zero centigrades; 2 – 4 C seems optimal.
After coming out of the fridge, plants still should be kept in rather low temperature for 1-2 months more; 8-12 centigrades seems to be optimal.This is the period when leaves and roots quickly develop. The tubers ripen a little later on, in a little higher temperature. If given high temperature, often just very small tubers develop quickly, plants believing a hot dry summer is close.
The best time to get all Central European Orchis out of the fridge is January. This means into the fridge 8-12 weeks earlier – with correct protocorm size!!

The time it takes to develop mature tubers on medium from seed-sowing varies markedly from species to species when grown asymbiotically. The seed of some will germinate just a few days after sowing whereas others will take two months and some require a cool treatment also after sowing. If the time of sowing is adjusted to the speed of growth and the specific requirements of the particular species, though, many nice little tubers will be produced on medium at the correct time for potting up in soil during the summer dormancy. It is important to give freshly de-flasked tubers a “semi-dry” resting period of 4 to 6 weeks after they have been transferred to soil in the summer. Afterwards, more regular watering and normal temperature fluctuations will result in uneventful continued growth. Use “suitable” soil and forget about the mycorhiza…

Mediterranean Orchis species, in common with Mediterranean Ophrys etc, require a dry or semi-dry resting period in soil after de-flasking of at least 4 months! It is not possible start them into growth earlier by watering them…you will kill them instead! The shorter dry rest period requirement of the Central European species is an adjustment to the different climate there, of course. This difference between plants of Mediterranean and central European origin depends on genetically programmed factors that may vary even between individuals of the same species.

Orchis mascula is rather easy to propagate, as illustrated by photos, but growth and success is not quite as strong as with most other Orchis/Anacamptis. Growth on medium after cool treatment “should” be a little stronger – compare photos of different species at that stage of development. Probably the medium could be improved, but it is a good start.

Sowing medium: Standard medium with Vaminolac + 0,5-1 cm3 potato cube in each flask à 20 ml medium plus 20ml/liter medium of pine-apple-juice (neutralized with NH3). Same medium as almost all Orchis/Anacamptis.

Sowing time and seed treatment: Germinates quite well without cool treatment. Usually sown in March-April with mature seed. Germination usually 90-100%, but a little un-even growth. Seed coats are rather thin, but can vary with different clones. Usually 0,5 % NaClO for 10-15 minutes.

Growth on medium: As most Central European Orchis/Anacamptis a little slow growth first summer and autumn on medium. Replate to fresh medium at 2-3 mm size and into the fridge at 4-5 mm size for 8-12 weeks. Out of the fridge Jan, still somewhat low temperature and leaves and tubers will develop.

Flowering: A few plants – however small – flowered first year in soil. Mostly, in good growing conditions, normally 2^{nd year in soil.}

Orchis militaris is very easy to propagate artificially on large scale on medium, but as previously mentioned we some years have problems with plants in soil during a Swedish winter. If kept outdoors a cold winter, the tubers freeze. If hosted in a frost-free cool green-house the shoots might rot because the temperature might go too high too early in the year. After some winters, however, the result is very good. This illustrate the specific requirements of the species for comparatively mild winters like those that occur on Gotland and Öland. Plants from Central Europe might behave differently.

Orchis militaris should be treated a little differently compared with most other Central European Orchis/Anacamptis when propagated on medium. Germination is close to 100%, survival on medium is excellent, but the first tuber produced on medium is rather small, and a second year on medium is better – compare with Orchis purpurea! Thus, the problem is mostly time and space.

Sowing medium: As for Orchis mascula.

Sowing time and seed treatment: As with most Orchis/Anacamptis here described, germination “should” occur on sterile medium early spring. Mature seed usually germinate within a few weeks to 10-25%. But if the plates are chilled in the fridge for 2-3 months after sowing, normally 100% quickly germinate when getting out of the fridge. I usually sow in October-November and keep them in the fridge until late January.Mostly rather thin seed coats (but thicker than those of O. morio and O. Spitzelii). I use 0,5-0,75% NaClO until bleaching.

Growth on medium: Form very long rhizoids and might clump together if sown too tightly. Replate in May-June. In autumn they will have an “indication” of a root and a small shoot. Now, it is time for cool treatment, but not into the fridge. Little Orchis militaris plants on medium like it much better if kept together with Anacamptis pyramidalis and Himantoglossum during autumn and winter = approx 6-10 degrees C and weak (fluorescent) light. See under these species! Following summer they will produce a small leaf and a rather small tuber, see photo. Either this little tuber can be potted in soil, or grown for another year on medium, preferably but not necessarily on fresh medium. This following winter, they should be kept cold. Following summer will produce big, healthy tubers to be potted when dormant.We have tried several times to speed up this process on medium to one season by different means – and so far killed more than 1 000 little plants…

Potting in soil: As mentioned, dormant tubers in summer, followed by a “semidry” resting period of 4-6 weeks.

Flowering: Third year in soil – but we have managed rather few plants to that size, due to climate problems

Orchis morio is very easy to propagate asymbiotically.

Growing medium: As O. mascula etc.

Sowing time: Late summer or very early autumn.

Seed treatment: Thin seed coats; 0,3-0,5% NaClO just 5 – 8 minutes. Normally 100% germination within a few weeks.

Growth on medium: Again, try to get protocorms, on fresh medium, into the fridge in Oct-early Decmber at 4-5 mm size. They will start to grow on, still in the fridge after 6-8 weeks. Now, out of the fridge, still rather low temperature. Big leaves and a big tuber will be produced.

Potting in soil: As other Orchis, dormant I summer.

Flowering: Often first year in soil, at least if given a not too cold first winter in soil. 100% will flower 2nd year in soil

Orchis laxiflora/palustris has been propagated on a few occations 10-12 years ago for a conservation project. The species are very easy to propagate and there is a 90 to 100% survival in soil. We did not retain our plants to flowering size, they were “returned” to Gotland.

Orchis purpurea is a somewhat variable but very beautiful species. It grows close to the coast in sothern Denmark but freezes if you try to grow it in the inland. It is more common in France and some other countries. It is very easy to propagate on medium if you just manage to germinate the mature seed. They have very thick seed coat. But once germinated, growth is good and uneventful.

Sowing medium: As Orchis mascula etc.

Sowing time and seed treatment: Very very thick seed coat. Germination “should” preferably come in March-April. In order to make that, seeds ether are sown in February or 2 to 3 months earlier and kept in the fridge for 2 to 3 months. The latter gives much better germination, normallt 20 to 50% germination rate if seeds are of good quality. But there are 1 000 seeds in each capsule – so even 10% germination is OK.

The very thick seed coat is best broken with 2% sulphuric acid for 10 minutes + sequentially 0,75-1% NaClO until the seed bleaches – which might take another 20-30 minutes!

Growth on medium: Initially slow, but uneventful. Fresh medium after summer and into the fridge in November for 8 weeks. Still somewhat low temperature when getting out of the fridge. By and by they will develop very big leaves, long roots and a big tuber.

Potting in soil: Like the other Orchis species, dormant in summer. 60 – 80% of the tubers will produce leaves early next spring if kept cool but frostfree over winter. They also can very successfullt be grown one year more on medium and then produce very big leaves and tubers, see photo!

Flowering: We have, doe to climate situation, just managed to raise single plants to flowering size, 3rd year in soil. (Most plants are sold after one year in soil.) However, the species should very likely be easy to propagate in large numbers in better climate zones!

Orchis pallens, tried a few times, has germinated very poorly from mature seed. We have just very few plants growing on. Maybe still a case for half-mature seed? New trials are going on.

Orchis simia is very easy to propagate from seed, and is a good “standard” for propagation technique of Central European Orchis,

Sowing medium: As O. mascula etc.

Sowing time and seed treatment: Somewhat thick seed coats, somewhat slow germination. Could be sown either February or 2-3 months earlier for 2-3 months in the fridge after sowing. Normally, after cool treatment, more than 50% of the seed will germinate. Sulphuric acid + NaClO or just rather strong NaClO seems to give the same result.

Growth on medium: Very uneventful. Fresh medium late summer/early autumn and into the fridge October or November for 8-10 weeks. Out of the fridge in January, rather soon weak light , but still somewhat low temperature. Healthy leaves and tubers will develop

Potting in soil: Like the others, dormant in summer. More than 90% of the tubers will develop leaves late autumn if kept frostfree.

Flowering: Hopefully we will have a few flowering plants in 2007, 3rd year in soil. The species has a rather strong growth and flowering 2nd year in soil should be possible in good growing conditions!

Orchis Spitzelii is a little tricky. Some years we have perfect result, plants behaving just like other Orchis species. Some years unexpected death on medium. However, probably also this poor result can be managed by a cool treatment with a correct timing. Also, there are 500 seeds in a single capsule and 100% germination rate, so comparative studies are easy to make.

Sowing medium: As O. mascula etc.

Sowing time and seed treatment: Thin seed coat, as O. morio. Sowing late summer, not too late in autumn. 100% germination within 4 weeks, but slightly slower growth than O. morio.

Growth on medium: As the other Orchis species, should preferably come into the fridge late autumn at 3-4-5 mm size. If kept in room temperature, this is the moment of mass death otherwise! When coming out of the fridge, in most cases they behave very well, producing a leaf and a rather big tuber, to be potted in soil dormant in summer.

Flowering: 3rd year in soil. 2nd would be possible if given a mild winter and a long growing season.

Orchis ustulata has only been tried in very small scale on a very few occations, due to lack of seed. Germination was poor from mature seed and only a few plants have been raised on medium. Recently a good number of seed has been sown, with the same planned technique etc as used on the other orchis species.

The great majority of this species sold from the Internet and plant nurseries over the last decade have certainly NOT been raised artificially but instead raided from the wild in placed like the Alps, Öland and Gotland.

Mediterranean Orchis species are in some cases just as easy to propagate as Ophrys and Serapias. Maybe a little surprizing – or maybe not – several species definitely benefit by being kept cool at 8-12 degrees C during their first winter on medium, corresponding to natural winter.. Several species grow well – and a few have failed at our first attempt, though, but new trials are under way…

Orchis papilionacea is a very variable species. Some subspecies grow better om potato + pine-apple medium, som better on “Ophrys medium” = 1 cm3 piece of turnip instead of potato + pine-apple juice. Orchis sancta grows very well on turnip medium. Excellent growth on medium. Orchis papilionacea can flower first year in soil, O. sancta 2nd year.

Orchis italica prefer the standard Orchis medium with potato + pine-apple juice. A little slow start on medium, but otherwise easy to propagate and to grow

Orchis coriophora and coriophora fragrans germinate within a few days on the same medium and quickly develop leaves, but later on behave a little like Orchis Spitzelii. Result is better if kept at lower temperature and not given light too early.

Orchis punctulata has been raised from seed once, just few plants due to few seed. Growth on medium was uneventful and we could keep the plants a few years but not to flowering size. Possibly we kept them too warm in winter – what is the winter temperature on Crimea?

Several other Mediterranean Orchis species, also Traunsteineria globosa have been sown in summer 2007. Potato + pine-apple medium seems to be very good.

Orchis hybrids can be raised between some species. For horticultural purposes, however, just a few might have any particular advantage. Perhaps the hybrid Orchis morio x papilionacea which has been raised commercially also in England since some years, could be hardy outdoors in Central Europe?

Other hybrids are mostly of curiosity. In some cases cross-pollination gives viable seed, producing viable plants, sometimes just a capsule without seed is formed, sometimes not even a capsule is formed.

Anacamptis pyramidalis grows in Sweden in coastal areas of Öland and Gotland. This indicates that it is sensitive to cold winters. It is very easy to propagate and grow on in large numbers, though.

Sowing medium: Standard medium + turnip – like Ophrys.

Sowing time and seed treatment: Usually 75-100% germination rate from mature seed. Thin seed coat, just 0,3-0,5% NaClO for 5-7 minutes. Should be sown rather early = February – April.

Growth on medium: Totally uneventful, but as many Orchis species rather slow start. Fresh medium in May-June. In early autumn NOT into the fridge, but kept in weak (fluorescent) light at temperatures of 8-10-12 degrees C during late summer and winter. Leaves and long, thin roots will develop during winter. Elevate the temperature by and by from April and a big tuber will quickly develop. Infthe plant/flask is kept in room temperature during winter, just a very small tuber will be procuced.

Potting in soil: Like Orchis, in summer with dormant tubers. 75-90% will develop leaves early autumn.

Flowering: In most cases 2nd year in soil, especially if given a little extra light in winter.

Very easy to propagate in large numbers, easy to grow on in suitable climate, and could be a very good garden plant.

Himantoglossum hircinum grows in central and southern Germany and southern England. It is common in France and in parts of the Mediterranean region, where other Himantoglossum species also may be found. Our experience is with the German type.

It is very easy to propagate from mature seed, produce large tubers on medium and grow on well in soil, if just given suitable growing conditions

Sowing medium: Like Orchis mascula etc.

Sowing time and seed treatment: Thin seed coats, short NaClO-time until bleaching. Best time for sowing is March-April. 50-100% germination within 4 weeks.

Growth on medium: Replate to fresh medium usually late May or early June. They will prioduce very big plants on medium, so just keep a few in each flask! Now, they should be grown as Anacamptis pyramidalis, in weak fluorescent light and temperatures of 8-10.-12 degrees C in autumn and winter. They will produce very big leaves and long roots. When temperature is raised a little in March.-April a very big tuber will ripen on medium.

Potting in soil: As usual, dormant in summer. “Semi-dry” resting period as Orchis/Anacamptis for 4-6 weeks. New leaves will develop early autumn from75-90% of the tubers. Frostfree + extra light during winter.

Flowering: We have managed to raise single plants to flowering size, 3rd year in soil. Better climate situation would make mass propagation easy.

Aceras anthropophorum has been raised just once earlier due to lack of seed. Germination – without cool treatment – was rather low, but once germinated, growth was uneventful on “Orchis medium”. A few plants will probably flower 2007, 3rd year in soil.

More seeds have been sown January 2007, and kept cool after sowing.