Dimorphorchis lowii yellowing leaves

[ChrisMalaga]

Hi everyone, I'm Christian from Spain and this is my first post!
I recently bought a Dimorphorchis lowii young plant, which came in pretty good conditions (it came from Germany and it's winter, but didn't show any cold damage whatsoever, so didn't all the other plants I bought from the same nursery).
Leaves had a bright green colour when I received it, but recently it's showing some yellowish patches, which seem to be extending really fast.
I'm growing it in a DIY self watering pot, as most of my recent orchids, which seem to do great. I don't see any damage on the roots (some are whitish, as it came in a black plastic pot), I'm giving it the same light as my Cattleyas, as I read these plants enjoy a good amount of light. My temperatures are around 20ºC (68ºF) and I use rain water.
I also don't see signs of rot, lack of water, excessive water... nothing! Any idea of what I could be doing wrong and how to solve this? All this happened in less than a week.
My first guess was that the light was excessive, as it could have been grown in less light, do you think this could be the cause?
If I didn't mess with attachments, you can see some pictures of the plant when I bought it (I removed it from the older pot to check the roots, it stayed in a plastic cup with some little bark for a night) and now in its final setup.
There was also a baby plant, separated from the other plant, which I potted separately and shows some discoloration too, but less than the other plant.
Thanks a lot for your help!

[estación seca]

Welcome to the Orchid Board!

I looked into this plant a while ago. It requires hot temperatures and high humidity. I suspect your temperatures and humidity are too low.

[Roberta]

First, Welcome!
That is a fascinating genus... I can't speak from experience because I have never tried to grow one. But temperature and possible cold damage comes to mind as a possible issue. That is why I have never tried it - I don't have much space for the really warm growers... and my research on it indicates that it it likes warm-to-hot So it possibly got a bit too cool in shipping, or maybe your home temperature is a bit too cool. (The other plants in your order might be a bit more forgiving) Is there a way that you can give it a bit more warmth? Perhaps a seedling heat mat.

[ChrisMalaga]

Hello, thank you for your replies
My humidity is 70%, pretty high in winter. Yes, the temperature might be a bit cool, but enough to actually cause damage?
I have a seedling heat mat where I'm growing some formerly rootless orchids, I was not considering temperatures close to 70F could be too cool for it. I will now put it on the seedling mat and see if the yellowing stops, or even reverts (I will cross fingers).

[Roberta]

Cold damage from shipping can take some time to show up. 20 deg C at night should be fine, but during the day, I think warmer might be better. Will it stop the yellowing? I don't know... but worth a try.

[estación seca]

From my reading regular temperatures around 70 F / 20C are probably too cold for this plant. The yellowing of the leaves could be cold damage.

[ChrisMalaga]

Hi everyone, I wanted to update the situation of my Dimorphorchis lowii a week later.
The yellowing seems to have stopped spreading. The yellow patches seem a bit more yellow, but I'm less scared to get a totally yellow plant now, as what was green remained green.
Also, there is a new root emerging from the base, which is nice
I did put the plant on a heating mat and it's still there, also, temperatures here raised a bit so it helps.
I also did use some Superthrive in low concentration, as some orchid friends suggested me, so maybe this helped too.
I will cross fingers for this plant

[jantigercat]

Originally Posted by ChrisMalaga

Hi everyone, I wanted to update the situation of my Dimorphorchis lowii a week later.
The yellowing seems to have stopped spreading. The yellow patches seem a bit more yellow, but I'm less scared to get a totally yellow plant now, as what was green remained green.
Also, there is a new root emerging from the base, which is nice
I did put the plant on a heating mat and it's still there, also, temperatures here raised a bit so it helps.
I also did use some Superthrive in low concentration, as some orchid friends suggested me, so maybe this helped too.
I will cross fingers for this plant

How’s your orchid going? I got one a week ago (shipped in the middle of winter, with heat packs of course). The medium was all over the the parcel box and I had to repot the orchid again. The roots were soaked in a very mild solution of SuperThrive. The plant is placed in an IKEA Greenhouse cabinet. Temperature ranges from 19-22C, humidity 70-80% or more.

The yellowing of lower leaves started a few days ago. I hope it stops!

[estación seca]

From my reading 22C is too low for this plant. It appears to need 25C minimum, higher most of the time.

[Louis_W]

Harry Zalenko wrote an article in orchids magazine a long while ago, and he grows them in his shade house in Quito Ecuador. Pretty intermediate there.... I'll try to find the article