Sudden brown/yellow
 

Would appreciate any advice on what might be happening with this cymbidium and how to best manage it. Thanks!

Recently moved the plant outside into a mini greenhouse in late autumn/early winter, noticed leaves yellowing a week later.

Sunburn. They needed to be acclimatized gradually.

How cold are your winters? Which Cymbidium is it? The large hybrids are fine (perhaps better) outside in winter unless you have substantial frosts.

Thanks for the replies! I have moved them into a more sheltered position and hopefully not too much damage has been done...

Our winters are mild. So far we have not approached freezing temperatures, however I would expect frosts in a month or two.

If you're willing to move it a bit, they flower better with naturally cooling fall/winter temperatures. Only bring it in when it will be at or below freezing, otherwise keep it outside in bright light.

Bit of a rookie question: how long would you expect them to take to develop flower spikes when kept in cool temperatures and adequate sunlight?

Flower spikes generally emerge in winter to early spring. Some say cool fall nights are critical for flowering the following spring. Others say cool winters are critical, and buds to flower 12-15 months hence form in new growths before they're visible.

It does look like it got toasted... Any chance that's a Cym. canaliculatum? (Leaves have that look, hard and "V" shaped cross section) If so, it not only doesn't need cold, it doesn't even particularly want it. I move mine to the greenhouse during the winter, and greatly reduce water. And it wants more filtered light than the standard Cyms too. So what works for standard Cymbidiums needs to be modified for some of the warmer-growing Australian species.

Now that you mention it, I think it is a Cym. canaliculatum! Thanks for the ID. I've unfortunately never had it flower despite growing it for years. Is the reduced winter watering required for flowering or would it still likely be incorrect lighting?

I moved it from inside of a large open window to the outside of the same window - in hindsight not the best idea. Goes to show how much glass filters the light I guess...

---------- Post added at 02:31 PM ---------- Previous post was at 02:28 PM ----------

I never really appreciated it was any different to a standard Cymbidium. So it will be handy to know I have to treat it a little bit differently moving forward. Thanks!

I don't know if it's the reduced watering that triggers flowering. But in nature, there is much less rain in winter - the "V" shaped leaves capture dew, and "channel" it to the roots. Hence the species name.

I do cut the amount of water in the winter. The greenhouse helps there too, I hang this plant at the end of the GH where I also have the Catasetinae. (I do give the Cym some water, maybe once a week or so) In late winter the spikes form, and then I start watering more regularly. But the key difference from all the rest of my Cyms is temperature - Cym. canaliculatum does not do well if it gets cold. I have found it to be much more sensitive than the other hard-leaved tropical Cyms like aloifolium, finlaysonianum, etc., which do stay out through the winter like all of the "normal" Cyms.

If you want your cymbidium to flower, you need to make friends with a bumblee bee.

Bumblebees bite plants to make them flower early, surprising scientists | National Geographic

just throwing in another hypothesis to get it to flower :biggrin:

There aren't any bumblebees in mainland Australia.