Why a spike but no flowers
 

This is Oncidium Rosey Sunset.

As you can see by the photo, there is a long spike but flowers have only been produced on the lowest part. The rest of the spike has no buds, and to the best of my knowledge never had anything that looked like buds. Plus there is another spike on the other side which I’m pretty sure has no buds at all - not even any swellings that look like they will develop into buds.

I bought this as a bag baby and this is its second year of flowering. Last year it did the same thing.

The plant is otherwise very healthy. The spikes are noticeably more attractive to mealy bugs then anything else I grow, but I’ve only seen a couple on it this year.

One thing I have noticed is that the developing spike usually gets ensnared by the enveloping leaf, and grows into a kind of U shape before I free it up. Maybe that is related?

Any ideas anyone?

I’d like to persist with this plant. I like the small-flowered red Oncidiums and this one is otherwise very tolerant and easy to grow.

Cheers
Arron

Could the spike still be developing? Maybe hasn't finished yet. Might be more activity to come later.

I’m pretty sure there is nothing there to develop. Same last year.

Does it get a fair bit of light? Light levels are ok?

Developing spikes getting stuck in leaves was my experience with this plant as well, but it didn't stop if from flowering. How are you temperatures before and during spike formation?

My experience with a stuck spike is generally inconsistent watering when the spike is developing. However, I've never had one without buds, so I can't speak to that.

The spikes developed in mid spring, so nothing odd about the temperatures. There were one or two days of around 35 degrees celsius, but mostly high twenties by day and about 15 at night. Is temperature a known issue with this problem, and if so is it being too high or too low.

Watering was consistent so no accordion-pleated leaves plus it’s other close relatives (Sharry baby, heaven scent etc) all developed spikes ok.

Grown outside in a shadehouse with 70% shadecloth roof so exposed to full days of tempered sunshine.

I forgot to mention there were two other spikes which did not survive being captured by the leaves, effectively breaking themselves.

Thinking about it, this is only a young plant so 4 spikes is a pretty good effort. I’d like to get it flowering properly.

Nice call on the possibility of temperature effects Arron. Will be interesting to see what happens for the next flowering after this one.

If your other orchids do just fine for every flowering, and only this one does something different every time, then could also consider the possibility of a genetic-related behaviour.

Just a thought, but what did you treat the mealy bugs with?

I didn’t. I just pulled them off. Never came back.