April 5, 2011

A Giant Australian Orchid Blooms

Dendrobium speciosum, an impressive specimen plant even with one spike in bloom.

This magnificent orchid plant, a true giant in the broad genus of Dendrobium, is native to Australia where is grows on protected cliffs in New South Wales. Indeed, it is one of the largest in the genus Dendrobium which limits who can grow it, for this is a plant that needs room, cold temperatures and muscles, if you ever plan to move it. Dendrobium is a genus which many of us are far too familiar with ( think - hardware store orchids in poly bags), but this species is hardly common,  for it is a giant wild form which is rather uncommon in the trade and thusy, in collections for many reasons, one of which is its massive size. A mature specimen plant can be 5 feet in diameter or more when in bloom, barely small enough to fit through a door. Match that with 3 inch thick pseudobulbs and the weight alone limits who can grow it.

I first saw this species while on a research trip to Japan two years ago, while there, I visited the Tokyo Grand Prix Orchid Show in February where I saw a huge specimen of this Dendrobium, and once back in my hotel room, I immediately started looking for a source, which was more difficult than I thought it would be ( I finally found this plant above, at the Santa Barbara Orchid Estate). I quickly ordered a plant via their website, without thinking about the size. When the UPS man delivered a four foot tall box, I started to realize what I was in for. Inside, the 5 gallon pot held a nearly mature specimen, but one that still needed a year or two under careful culture before it would bloom.

Detail of the floral spike

Dendrobium speciosum is considered a cool-grower, and it will do find in a greenhouse like ours, where winter temperatures are maintained around 40 degrees F. This plant spends the summer outdoors, where it receives fresh rainwater which is essential for most orchids, as well as a light dose of liquid fertilizer every two weeks. The plant lives in a large terra cotta pot in a wood bark mix ( Aussie Gold) which is refreshed annually. As many of you know, I am not an orchid grower, and the few plants that I do keep are sturdy, and not considered fussy by any means. What they do share in common is limited to the temperature range, for the cool to cold climate of my greenhouse limits what orchids I can grow well.


  1. That orchid is stunning! Wow! And so is your greenhouse!

  2. Great orchid but I also love the Geranium in the back of the last picture. :)

  3. Thanks. Yes, that Geranium of course is G. maderense 'alba', one of a few that I started from seed a couple of years ago. Any hints on how to get it to bloom? That one I planted in a 30 inch pot, to see if size matters. I let it go dry for most of the winter, maybe that will help.

  4. Just found this again. Here in California obviously I didn't really have to do anything to get mine to bloom. It just did its second year. My friend Marc at the NYBG grows them under glass though and he would probably recommend just fertilizing the hell out of it.


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