Two Oncidium hybrids not doing well
 

Hi. I have about 30 Oncidium intergeneric hybrids which are all growing very well. Except two. These two seem to be going backwards.

The two concerned are

Degamoara Skywalker “red star”

And

Odontocidium Tiger Crow “golden girl”

The rest of my plants in this alliance are just a random collection of old favourites - so across a pretty broad spectrum - and as I said, all doing very well with lots of green growth and some very impressive flowering this year. This is despite the fact that I obsess over my cattleyas but expect the Oncids to grow like weeds in the background.

I grow all my oncid hybrids the same, with no acknowledgement of possible individual preferences.

So I’m wondering if there is something different about the culture of these two which I have overlooked?

I grow them all in an unheated shadehouse, year round. Water 2 of 3 days in summer. Fertilise about every ten days - probably a bit heavy handed with the fertiliser. Cattleya light conditions. Fairly crowded.

The only thing I can think of is this summer has been unusually hot. And humid too.

Maybe they are just the most heat sensitive of the bunch?

I know I haven’t given enough information for a diagnosis, and no photos, but I’m really just asking of those who grow them the question do they grow like most of the rest of the alliance, or are they outliers somehow?

Cheers, and thanks
Arron

I would not consider them to be particular outliers in terms of their cultural requirements or vigor. Although these intergenerics have species with cooler growing preferences in their background, they have plenty of warmth tolerant and/or warm growing species to balance it out. Overall, their requirements are pretty standard (in comparison to other oncidium alliance hybrids).

Another factor in my opinion is that both of these are named clones (not just random seedlings). These have been selected for flower quality but also suitability for growing in a wide range of conditions. They are quite tolerant of a lot of abuse.

In a suitably large collection, you're going to have plants that just fail to thrive for any number of reasons from random chance to accidents and (intentional or otherwise) negligence. You may want to double check the roots of these plants and repot when appropriate. Until then, they may need to be kept in shaded conditions or treated for pests or given a boost with some root stimulants -- basically just to give them a better chance of survival. But like you said with no photos or any information on how you grow them, these are just very general suggestions/guesses.