Occasionally an orchid grower will show me a plant that they’ve just bought and ask when I thought it would flower. In the case of recently de-flasked cymbidium seedlings, my estimate of five years sometime sends the buyer into shock! Flowering cymbidiums are cheap, considering the time it takes to raise them from seed. Struck back-bulbs take less time to flower, because their growth is assisted by nutrients stored in the back-bulb, but they still take three or four years.
The above estimates are based on personal experience in the case of plants raised in a shade-house with a fibreglass roof and open sides. This type of construction traps little extra heat in winter and the plants are not much warmer than if grown in the open. Most professional cymbidium growers grow their plants in plastic tunnel houses, a big advantage in winter as they effectively trap winter sunshine, so that their internal temperature rapidly rises into the twenties whenever the sun shines. Some professional growers also supply artificial heat in winter to maintain their young seedlings at a minimum temperature of 12-15˚C. Under these conditions they are able to flower most of their cymbidium seedlings in as little as three years. But don’t expect to do the same consistently unless you can provide similar growing conditions.
While plastic tunnel houses have a distinct advantage in terms of promoting rapid growth and early flowering during the cooler months, they have a big disadvantage in summer. At that time they can become excessively hot and stuffy, providing prime conditions for the development of scale and spider mite, unless they are fitted with powerful cooling fans. An open shade-house is better at that time of year because the plants are fully exposed to any cool breezes that nature brings.
Most newly de-flasked Australian native dendrobium seedlings also take four or five years to flower, although of course it depends on their size when taken from the flask. Some take considerably longer. In my experience Dendrobium speciosum seedlings take about ten years to reach flowering size, and some of their seedlings take almost as long, especially in those cases where the other parent was a hybrid bred from D. speciosum. These estimates apply to plants grown in Melbourne. Growers in NSW or Queensland can flower their native orchids several years earlier, mainly because of their sunnier, warmer winter weather.
In my experience, disas grow to flowering size more quickly than any other orchid. They routinely flower less than two years after de-flasking, and occasionally they produce flowers in less than a year. Be warned, though, they are much less forgiving of poor culture than are cymbidiums or Australian native dendrobiums. Even experienced orchid growers have sometimes failed to grow disas successfully and have given them up in disgust. On the other hand, ‘new chums’ sometimes achieve spectacular success, which really annoys the ‘expert’!
Some growers have told me that they prefer to buy mature plants and won’t buy orchid seedlings because of the time it takes to flower them. I sometimes agree with them, but only if they’re pushing ninety and looking a little off-colour! Youngsters like me in their 70s are well advised to keep buying seedlings, as it’s the only way they stand a chance of acquiring a show champion, unless they’re willing to part with big money! Show champions are highly valued by their owners, who require considerable financial persuasion to part with them. If you buy a few seedlings each year, and patiently wait out the gestation period of five years, eventually you will have the pleasure of seeing a succession of seedlings flower for you.