There is no doubt that orchids are very beautiful plants. And that’s why there is a great chance that you would be glad to spare the beauty of your orchids with your good friends, relatives, or any other orchid growers. Orchids are rather slowly growing plants and they are hardly propagated by classic methods, and incorrect technique could kill the plant. So, orchids are unique plants with features that define the methods of propagation that you should consider. All orchids are obligate mycoheterotrophs at early stages of life and their seeds are tiny and don’t contain nutrients, instead plantlet needs specific symbiotic fungus to germinate and be fed with all organic and inorganic nutrients. And only after one year, a plantlet becomes strongly enough to rely on own photosynthetic potential. Thus, successful orchid propagation needs specific knowledge to do it in a proper way.
The first method of orchid propagation (and one of the most hard) is seed propagation. Given the fact that orchid seeds don’t contain nutrients, they are able to germinate only within specific conditions. There are two ways to germinate them – either by supplying them with symbiotic fungus, or by supplying them with nutrient medium. First way (so called symbiotic culture) is quite easy but ineffective. You should only sow your seeds on used substrate were mother plant was grown and then create humid conditions to germinate the seeds. Old substrate contain symbiotic fungus, and if you keep it humid, fungus will germinate the seeds, and eventually you will see little green pallets, which after roughly one year will form true leaves and roots. But as I said this method is quite ineffective – only very small amount of seeds will germinate, and there is a great chance that even germinated seedlings will die if conditions are not optimal. Another method of seed propagation is so called in vitro culture. This is a very effective method – all orchid vendors use this method to propagate orchids at commercial scale. One orchid seed pod contains millions of seeds, so you can produce thousands of plants. But you need sterile laboratory, nutrient media and skills to do that, it is nearly impossible (and not practical, if you don’t want to become a professional orchid breeder) to establish such a laboratory.
The second (and also very hard) method of orchid propagation is mericlonal propagation. This is also laboratory technique – you also need laboratory, equipment, laminar box and specific different nutrient media with phytohormones. This is also technique not for home use. This method is used when you should propagate definite clone (either species or hybrid) with unique features – that’s why so called mericlones are often quite expensive – for instance famous Phalaenopsis tetraspis C1 mericlone.
Orchid propagation by division
Another method of orchid propagation is division of a plant. Sympodial orchids such as Cattleyas, Oncidiums and its intergenerics, Cymbidiums, Dendrobiums, Paphiopedilums, Stanhopeas and other could be propagated by division. To do that, you should remove plant from its pot, cut rhizome, and eventually you will have two plants instead of one. But there is some peculiarities. First, you should have clean and disinfected knife, and you should clean and disinfect it after each cutting, because you may infect your plant with incurable virus infection. The second thing to consider is that you should have at least three mature pseudobulbs in each division, and it’s better if it would be five pseudobulbs in division. Divisions with lesser amount of pseudobulbs are not so viable and don’t flower until gain a normal size.
There is also one interesting method of orchid propagation by backbulbs. Backbulbs are old leafless pseudobubs, which are often removed for aesthetic reasons. But they are often have at least one viable latent buds, which in proper conditions could activate and form new growth. To do that, you should put removed pseudobulbs with small amount of substrate into a plastic bag and provide it with warmth and light. When bud is activated and new growth is visible, you should open this plastic bag to ensure that new growth will not rot and to expose it to a fresh air to strengthen the new growth.
Propagation by cuttings
Dendrobium, Jewel orchids and reed stem Epidendrums can be propagated by cuttings – their pseudobulbs are rather long and have many nodes, which have ability to form new growths. To propagate orchid in such way, you should take cutting from such pseudobulb (which should have at least five nodes) and simply put it in pot with medium, lover nodes will eventually produce new shots. And some Jewell orchids (particularly Ludisia) can produce roots even in water.
Some orchids (especially Phalaenopsis and Dendrobiums) can be propagated by keikis. Keiki is a plantlet, formed from a generative bud, which is converted to a plantlet in specific conditions – too warm temperatures (Dendrobium nobile often produce keiki instead flowers, if cool dormancy is not provided), too much Nitrogen or too low light can activate keiki formation. Keiki with at least 3 cm length roots can be removed and potted in separate pot. And there is a keiki paste with cytokinine which stimulates keiki formation when the paste is applied to flower buds. Given the fact that Phalaenopsis (and other monopodial orchids) are nearly impossible to propagate by other methods, keiki is a good way to do that.
Micropropagation of Orchids
Kay S. Greisen