Extra long spike, few flowers

[empiref]

Hello Everyone,

Bought this Phal two years ago, was planted in sphagnum moss; moved it to S/H right away and it thrived; the phal came with two flower spikes.

It has been growing new leaves and roots ever since I moved it; flush + fertilize + Kelpmax regularly. It has 15 leaves.

This year two spikes started to emerge, after a while, and when they reached about 15 cm in length, they stopped growing and a third spike emerged; length more than 65 cm and only a few flowers seem to be appearing.

Any help from the experts on the matter, am I doing anything wrong?

[turock]

Strange... My first thought is that maybe it's not getting a long enough cool period. Phals are quite sensitive to temperature, and need to remain at temperatures lower than 26 C / 79 F for four to five weeks in order to put out a spike.

If that plant is subjected to higher temperatures, 28 C / 82 F for even as little as 8-12 hours before the blooms open, it can stop a spike from blooming. High temperatures can cause a spike to elongate and produce less flowers, and possibly a keiki.

Here are some articles to read, if you're interested:
Optimal flowering temps
Inhibition of flowering

---------- Post added at 09:43 AM ---------- Previous post was at 09:39 AM ----------

I have found with my own phals, though, that if I put them through a cool period while they are currently in flower, they will frequently produce more flowers on the same spike without any other effort on my part.

So, try cooling it down! I really hope it works, because that plant is just gorgeous! I would love to have a peach-colored phal like that one!

[mtorchid]

How do you maintain a water reservoir with that pot? Does it sit inside another container?

[empiref]

Originally Posted by turock

Strange... My first thought is that maybe it's not getting a long enough cool period. Phals are quite sensitive to temperature, and need to remain at temperatures lower than 26 C / 79 F for four to five weeks in order to put out a spike.

If that plant is subjected to higher temperatures, 28 C / 82 F for even as little as 8-12 hours before the blooms open, it can stop a spike from blooming. High temperatures can cause a spike to elongate and produce less flowers, and possibly a keiki.

Here are some articles to read, if you're interested:
Optimal flowering temps
Inhibition of flowering

---------- Post added at 09:43 AM ---------- Previous post was at 09:39 AM ----------

I have found with my own phals, though, that if I put them through a cool period while they are currently in flower, they will frequently produce more flowers on the same spike without any other effort on my part.

So, try cooling it down! I really hope it works, because that plant is just gorgeous! I would love to have a peach-colored phal like that one!

Thank you very much for your help; this is another Phal with the same growing condition and care...
I am just going to let it be and see where this is going to lead to.

[empiref]

Originally Posted by mtorchid

How do you maintain a water reservoir with that pot? Does it sit inside another container?

Nope, the reservoir is at the bottom of the same pot.

[mtorchid]

Okay, so can you regulate the amount (depth) of water in the pot/reservoir?

[empiref]

Originally Posted by mtorchid

Okay, so can you regulate the amount (depth) of water in the pot/reservoir?

I am not sure I understand what you mean; but it is a standard pot which I turned into a semi-hydro pot, 2 side holes at about 2 inches high from the bottom.

The plants are always flushed when watered, and the bottom reservoirs are always almost full.

[mtorchid]

Got it! At first the pot looked like a standard pot. I think Phals are the least tolerant orchid for any S/H errors. Mine did "fine" in S/H but really started to thrive when I put them in wooden baskets with the clay pellets. I water more often of course, but they really like their airier environment. That strange spike aside, yours seem to happy in their S/H environment.

P.S., In S/H I had a lot of "aerial roots" but no such thing now in the LECA and baskets. Maybe before they were trying to climb out of their S/H environment ;-)

[Orchid Whisperer]

Regarding your original post, I have experienced a similar problem. I don't have a definitive answer, but my current theory is too much nitrogen/fertilizer while the spike was developing.

For quite a while, I had many young plants with a lot of growing to do before blooming, so I used a high nitrogen fertilizer to promote growth. I have recently switched to a so-callef "bloom boost" formulation where N is lower relative to P and K (11-35-15, I think). I used to provide fertilizer weekly, at 1/4 the recommended strength, now it's more like 1/4 strength once or twice a month. From what I've read, I think the lower N fuels less vegetative growth, allowing more flower production from a well-nourished plant. Has nothing to do with having more P in the fertilizer. You could probably achieve the same thing by just using fertilizer less often or at even lower strength.

So far, Phals that have put out spikes since I changed fertilizer regime are not leggy and have more flowers per spike.

So, that's my working theory . . . or I could be completely full of crap. I want to see the rest of my Phals flower before claiming victory.