Dendrobium Spectabile - How to Bloom?

[Syrinth]

Hey everyone, so I have two Dendrobium Spectabile flowers, both are of blooming size and were in bloom when I got them.

they haven't bloomed once since I got them. One was purchased last April, which makes sense why it hasn't rebloomed yet, the other though, was purchased some two years ago.

They are currently situated in a South facing window with the blinds partially folded so that they don't burn. I've tried giving them lots of light previously but figured that purple canes are bad,

They have been producing new canes and the canes are as tall as the previous ones and just as plump, if not plumper.

Any ideas?

[WhiteRabbit]

When the sun is high in the sky (mid spring through early autumn), a south facing window may not be sufficient light ? I know that my south facing windows get no direct sun during that time. I only have a not yet bloom size spectabile, so I can't say specifically for that species, but have (and do) bloom other Latouria Dens in west facing windows that get direct sun from mid-afternoon on.

Hopefully members with more spectabile experience than myself can be of better help.

[Orchid Whisperer]

I am no expert, but I can tell you what I did before my D. spectabile bloomed (unexpectedly). See Dendrobium spectabile - keiki? Or really premature spike? This plant bloomed on a 17 cm cane (6.5 inches).

I mostly grow D. spectabile as a warm-growing type with no true rest period. I grow outdoors in the summer when the weather permits, in Cattleya level light (bright but diffuse, under minimal shade cloth).

It is growing in scoria ("lava rock") with about 10% each coarse charcoal and coarse fir bark. I fertilize similar to many of my other orchids, 11-35-15, about 1cc/ 4 liters, with added calcium, magnesium and sulfur from gypsum and Epsom salts. Fertilizer given about twice a month during active growth in summer, less in winter.

Toward the end of summer and into autumn it received a lot rain as the weather was cooling. This is when I noticed the spike developing. I brought it in as night temperatures dipped to 40 F. So, the spike came after a cool down, but not really a dry period. If I were following instructions usually given for Latourias, I would likely let the plant dry a little more during the cool period.

*** EDIT *** fixed link above

[Orchid Whisperer]

Corrected link provided above

[rbarata]

Taken from Orchidsamore.com:

It needs to be 4-5 years old to flower. At this time, they will have 4-7 canes and be about 18-24 inches high. Plants start to reach their full potential when the get to be 7-10 years old and reach 3 feet or more in height.

Maybe this is your problem?

[Orchid Whisperer]

Originally Posted by rbarata

Taken from Orchidsamore.com:

It needs to be 4-5 years old to flower. At this time, they will have 4-7 canes and be about 18-24 inches high. Plants start to reach their full potential when the get to be 7-10 years old and reach 3 feet or more in height.

Maybe this is your problem?

I think that since the plant bloomed before, it should be able to bloom again.

[Syrinth]

They are both blooming size yes. I'm going to try putting one down in the basement overnights, see if the cooling down will help it get a kickstart.

[NYCorchidman]

They might bloom any time now.
I suspect the light is the issue.
They might bloom with lesser than ideal light, but it is recommended that D. spectabile get very strong light. So, yeah, nothign wrong with purple cane.
Yellowing leaves are different story. lol

I remember seeing a picture of this species in situ in the full sun with no trees shading at all. The whole plant was just covered in glorious blooms!!!

Good luck!