Cattalya leaf turning yellow from leaf tip to base

[Mercurianmad]

Hey guys! I have this black Ann Cleo “callyn” cattalya. It’s growing lots of new roots and the waxy white covering on the new leaf has turned brown and fallen off.

The leaf in question has sunburn damage from the nursery on the top of the leaf. The leaf itself seemed fine until last week, when I noticed this big yellow stripe going down the leaf. Why is this happening?

I water once a week when the pot is just dried out. I give it a probiotic twice a month, fertilize weakly for three weeks in a row with MSU orchid fertilizer, I fertilize once a month with kelp max.

[SouthPark]

Originally Posted by Mercurianmad

Hey guys! I have this black Ann Cleo “callyn” cattalya. It’s growing lots of new roots and the waxy white covering on the new leaf has turned brown and fallen off.

The leaf in question has sunburn damage from the nursery on the top of the leaf. The leaf itself seemed fine until last week, when I noticed this big yellow stripe going down the leaf. Why is this happening?

Growing lots of new roots is GOOD (actually great).

As for a new leaf falling off ----- that's not good. Normally, if the sun damage is limited, the damaged portion turns turns dark black coloured and dries up. And maybe later changing to brown or tan colour.

Just monitor the orchid for now. The orchid is repotted, right? So once it came in, you potted/re-potted?

For now - provide medium light (no direct sun), nice growing temperature, and make sure the roots don't get waterlogged ----- seems like you don't waterlog the roots, so that should be ok. And some gentle air-movement will be good too. Also - if there are any concerns with the state of the roots ----- then can check the roots inside the pot --- just in case - to make sure they're ok.

But - now ---- since you mention new roots are sprouting well ------ then that is good. So just monitor the situation for now.

Also - watch out for overdoing any fertilising .... such as "fertilize weakly for three weeks in a row" ------ which sounds ok ..... but watch for any salt build up in the media --- just in case. Also may need to clarify the meaning here - of three weeks fertilising in a row.

[rbarata]

We need to know your environmental conditions: temp, light, humidity, etc.
But it seems to me that is just an old leaf. The yellowing seems to be happening on all leafs and with the same position which indicates the areas that get more light.

[SouthPark]

Nice post from rbarata. MM ------ if everything is stable, as in other leaves don't do the same thing, and if you get new growths (leads) coming out ------- then that will be a good sign later.

Originally Posted by Mercurianmad

the waxy white covering on the new leaf has turned brown and fallen off.

When a new leaf drops off ----- it is a concern. But if it had been badly damaged from say sunburn etc, then understandable.

Totally agree with rbarata. Yellowing of leaves - departure from dark green etc ...... will occur when the light is relatively bright - such as direct sunlight. It is ok - up to a point. Don't want to get overly yellow ----- as that could start hurting the leaves.

[rbarata]

Didn't read carefully...phone screen without glasses....it was a new leaf.
Do you have photos before the leaf drop?

[Mercurianmad]

Some clarification: no new leaves fell off. What fell off was that little paper sheet that covers the new leaf bulb as it’s growing. If that makes sense. That fell off. The New Leaf is doing fine.

I’ve raised the Led lights away from the leaves slightly and turned the light intensity down one notch. If it’s just due to too much light will the yellow in reverse and will the leaf go back to being green?

My temperature goes from 66 to 71°. Humidity goes from 61 to 79.

[Steve83]

Remember, the old pseudobulbd and leaves are a nutrient store. They are yellowing because the plant is growing, and not getting enough nutrients. Water more often if your mix allows.

I was having a similar issue with some catts under cmh, and once I bumped up to daily watering at 25 ppm N, they look much better, and are growing faster as well. Just gave them their first dose of kelpmax yesterday.

[SouthPark]

Originally Posted by Mercurianmad

What fell off was that little paper sheet that covers the new leaf bulb as it’s growing. If that makes sense. That fell off. The New Leaf is doing fine.

That's good news MM. So maybe the leaf sheath just fell off, which is ok. The leaf sheath is the covering over new leaves, while flower bud sheaths are a different thing.

If your light level becomes reduced, and if the yellowing was due to relatively bright light, then leaves can indeed green-up again.

The activity you mentioned - such as growing lot of new roots ------ is a good sign actually. So assume for now that your plant is actually ok.