Oncidiums that grow but don't flower

[Zabeta]

Hi everyone,

I'm hoping you can give me some perspective on oncidium care. I have a couple that keep growing like crazy (4-6 pseudobulbs in a year), but they show no signs of blooming. I've had both for about a year, and only one was blooming when I got it.

1) Oncidesa Lemon Heart 'Baby Face'. When I received this in April 2015 (was not in bloom), I put it in coconut husk. What I have is 1/2 of a division (the other half didn't make it). It didn't do well in coconut husk, so in Oct. 2015 I changed it into full water culture (I keep a small amount of water at the bottom of the container - not enough to rot the roots, but enough for it to constantly soak up the water). It's not ideal, but the plant has plumped out and is growing new pseudobulbs. It was an emergency measure to help it get the water that it needed (in a horribly dry and hot climate), but eventually I'd like to put it in bark.

2) NoID "dancing lady" type. This one's in orchiata and sphagnum, and I try not to let it completely dry out, watering one to three times per week, depending on weather.

For both, I fed with small amounts of K-Lite, punctuated seldomly with Kelpmax or pure water. I use reverse osmosis. They both get bright morning sun and diffused afternoon/evening sun in a south-facing window. Temperatures are generally warm to hot in the summer, with up to a 40 degree drop at night. The winter has been very nice this year with cooler, but not cold, temperatures and lots of humidity (lots for me is 60%). I have recently added DynaGrow fertilizer to the rotation, and stepped up the frequency of Kelpmax.

My suspicions:

- I'm not patient enough (?).
- The K-Lite alone was too much nitrogen and not enough phosphorus, and I should have rotated fertilizers.
- The hot, dry weather last summer was too much and now they need to recover.

Any thoughts? They seem to be happy-ish, judging from the fact that they keep growing more and more pseudobulbs, but I'm getting really bored, and I'm wondering if there's something wrong that I need to address.

[bil]

I have a yellow ' dancing lady' oncidium. It is in pure bark (small size) and get's very weak K lite with kelp once a month. It flowers every year without fail Its light is 50% shade about.

[WhiteRabbit]

I don't think that K-Lite at recommended or lower dilution is likely to be too much nitrogen.

In my years taking note of such things - my south facing window gets no direct sun in summer (and is in fact losing sun quickly now). I've had much success with Oncidiums in an east or west exposure.

So - if you've had them "about a year" - a bit more? a bit less? It may be that a bit more patience is needed. Have the new pbulbs matured? Have they started new growth? Many Oncidiums spike after the new growths have fully matured.

The first one you described - if it was set back last year, it may have been recovering for a while, which could set it back, bloomwise.

ETA: About the Oncidesa - I have some (all Nanboh Waltz) - When I had one inside it did not bloom; I don't know if it was insufficient light, OR if perhaps it wanted some cooler temps to bloom. It was in a window that I would expect to be enough light - I've have a Den, Neofinetia, Neostylis, a compact Catt hybrid all bloom there They all bloom quite well for me outside, being on the east, west, or north sides of my house.

[Zabeta]

Thanks, Whiterabbit. You're right about the south window losing direct sunlight in summer - last summer I supplemented with a full-spectrum lightbulb and I plan to do that again this summer. I'm still getting some direct light, especially in the morning. Unfortunately it's either south or a north window with an awning, so south it is. I have no option to put them outside, so your observations on the oncidesa make me sad.

I've had them both 11 months. The pb have matured and started growths of their own, but they're significantly smaller than the older ones they came with. Each new round is a tiny bit bigger than the previous, but they're all still pretty small.

As for fertilizer, another thread got me convinced that the low P numbers on K-Lite could potentially have inhibited blooming, so I decided to add DynaGrow as part of the rotation. It's very annoying, though, to have the different fertilizers for different stages - some of mine are ready to bloom, and others are growing. I only have one watering container, and I don't like to waste water (or fertilizer). The whole regime is just very annoying. So I'm in a transitional time as I figure out what I can live with in the fertilizer routine.

I guess I'll wait a while longer and hope something happens. :-)

[silken]

If you go with a balanced fertilizer such as 20-20-20 you should be OK and not have to keep switching.

[gngrhill]

Originally Posted by silken

If you go with a balanced fertilizer such as 20-20-20 you should be OK and not have to keep switching.

What Silken says. Also light is important for oncidiums. Mine get full south window light and are all in bloom. I have one in an East window that grows beautiful leaves, but also does not bloom easily.

[Zabeta]

Originally Posted by silken

If you go with a balanced fertilizer such as 20-20-20 you should be OK and not have to keep switching.

That certainly does seem like the easiest option.

---------- Post added at 08:37 PM ---------- Previous post was at 08:36 PM ----------

Originally Posted by gngrhill

What Silken says. Also light is important for oncidiums. Mine get full south window light and are all in bloom. I have one in an East window that grows beautiful leaves, but also does not bloom easily.

That's interesting - I was under the impression that oncidiums required significantly less light than that. I'll experiment with putting them closer to the window.

[Ray]

Originally Posted by Zabeta

As for fertilizer, another thread got me convinced that the low P numbers on K-Lite could potentially have inhibited blooming

There is absolutely no validity to that.

Orchids are roughly 95% water. Nitrogen and carbon make up 80% of the rest, with P, K, and everything else making up the balance.

I have used K-Lite exclusively @ 25-35 ppm N in RO water at every watering since November of 2011, supplemented monthly with KelpMax @ one tablespoon per gallon (I might skip a month or two in winter, but that's laziness, not by plan), and my plants have never grown or bloomed better.

[Zabeta]

Originally Posted by Ray

There is absolutely no validity to that.

Orchids are roughly 95% water. Nitrogen and carbon make up 80% of the rest, with P, K, and everything else making up the balance.

I have used K-Lite exclusively @ 25-35 ppm N in RO water at every watering since November of 2011, supplemented monthly with KelpMax @ one tablespoon per gallon (I might skip a month or two in winter, but that's laziness, not by plan), and my plants have never grown or bloomed better.

Good to know, thanks. I wasn't supplementing much with the Kelpmax. If nothing else, that will be a change I'll make.

[bil]

Gotta say, agree with Ray. Mine have all been on his regime for over a year now, the blooms are great, and as the blooms are going the new shoots are coming thick and fast.

If your oncs are a dark green, I have heard people say that they need more light.