Phal produces spikes but no flowers

[camille1585]

I have a Phal tetraspis cross since over 2 years, which has produced 3 spikes in that time, but never any flowers. There are the bracts under which the buds would normally develop, but no buds ever appear.

The plant in question is a Phal. (amabilis x tetraspis C#1) x tetraspis C#1. It's now producing a new spike, so I'd love to finally see some flowers.

It's growing with my other Phals by a south facing window where it gets a few hours early/late sun and the rest of the time bright shade. I have it under lights this winter since it's been extremely rainy and overcast. Temperature is generally between 20-26°C, occasionally dipping to 17°C at night in the winter, humidity in the 35-70% range. (For the folks in the US, that would be roughly 68-80°F with a low of 63°F). It gets 50ppm N of MSU fertilizer most waterings.

Is this plant a dud or is something missing or not to its liking?

[Ray]

I have found tetraspis to be one of the “hot growers” among phals, along with bellina and venosa, and I try to never let them see below 21-22C.

Can I confirm that to be the issue? No, but it’s a “gut feel” based upon my history with them.

[camille1585]

Thanks for the input, and it's something easy enough to test by getting a heat mat. I used to be able to get higher day temps in the winter when I was using fluorescent lights, but then I updated to LEDs shortly before getting the tetraspis cross, and they generate nearly zero heat compared to the old fixtures...

I was planning on buying a pure tetraspis soon, but I may hold off on that purchase until I've determined if your gut feeling was correct.

[jcec1]

I get the same with any cross that has tetraspis in it - lots of spikes but no bloom or few blooms - tetraspis and speciosa species bloom fine. I think there that the tetraspis parentage has been an issue for me.

This is Crimson cherub x tetraspis which has loads of spikes but rarely blooms and tetraspis C1 which both grow in the same window under the same conditions, so I don't believe it to be a temperature issue.

[camille1585]

Originally Posted by jcec1

I get the same with any cross that has tetraspis in it - lots of spikes but no bloom or few blooms - tetraspis and speciosa species bloom fine. I think there that the tetraspis parentage has been an issue for me.

This is Crimson cherub x tetraspis which has loads of spikes but rarely blooms and tetraspis C1 which both grow in the same window under the same conditions, so I don't believe it to be a temperature issue.

That bloomless Phal is impressive! Though for all the wrong reasons... I admire your patience with that plant.
I'm thinking that my next step is to contact the grower I got it from (Orchideen Lucke) to see if they have any advice.


I also put my thermometer next to the Phal today under the lights. On a shelf without lights the temperature was 20°C. Where the Phal is it's a nice 25°C! The LEDs warm the plants more than I thought (probably due to the warmth of the fixture on the shelf directly below.) But since the lighhts are off at night, the temperature drops quite a bit.

[jcec1]

Originally Posted by camille1585

That bloomless Phal is impressive! Though for all the wrong reasons... I admire your patience with that plant.
I'm thinking that my next step is to contact the grower I got it from (Orchideen Lucke) to see if they have any advice.


I also put my thermometer next to the Phal today under the lights. On a shelf without lights the temperature was 20°C. Where the Phal is it's a nice 25°C! The LEDs warm the plants more than I thought (probably due to the warmth of the fixture on the shelf directly below.) But since the lighhts are off at night, the temperature drops quite a bit.

Share any thoughts or recommendations that they may have please.