DenPhal indentations on leaves

[KristenReuel]

I bought this NOID den/phal for next to nothing during the winter. It looked almost dead, but soon put out a new growth that grew so fast I thought it would reach the moon.

However, it has recently stopped growing, and there are indented spots on the leaves. At first I thought it might be sunburn, but the bottoms of the leaves are much worse than the tops. I haven't seen any pests on my orchids, except for one that had those miniscule little bugs that eat decaying matter.

The denphal has TONS of roots with growing tips. I repotted it once I received it into woodchips/coconut husk. I think I should have washed the coco husk more, but the roots are growing like crazy and when I water it the water now runs clear.

The indentations appear to be radiating around the base of the leaves, near the stem. I'm also certain that no water would have gotten in there. What could it be?

[WhiteRabbit]

My guess would be some type of pest ... Hopefully others have suggestions as to what type.

[KristenReuel]

I wish it were a pest so I could kill it quickly. I'm nervous about it because it's been very close to my other orchids. The indentations look worse in real life

[NYCorchidman]

Mystery...

I actually had one of my dendrobium (the den phal type also) having the same issues.
I had it for a couple of years and the whole time I had it, it grew and bloomed (4 times) fine.
Then this spring, it put out two new canes.
One of the new canes began to show these same symptoms. I initially thought mites, but did not find anything. Mine only had marks on the underside of the leaves and some on the cane where the leaves attach.

Mine was actually growing fine, and the indentation marks were a bit smaller in size, but there were many, and there were mostly near the end where leaves attach to the cane.


I actually really freaked out over it and just pitched it in fear of whatever it is might jump onto my other more valuable plants.

I thought about giving it away because it was otherwise growing fine and was coming into spikes. It is also very floriferous and fragrant hybrid, but not knowing what the issue was, I thought it was not a nice thing to give it to someone.

Sorry, I can't be of much help.
Keep an eye on it and also, try and wipe the leaves often.
Segregate it away from other plants if that is an option for you.

Last, one other occasion that I saw something similar to this was the slug damage on my slipper orchid.
Normally, large garden snails or slugs will eat tender leaves like edible veggies, flowers, or root tips, and leave holes.
I did not expect they will attack rather hard and thick leaves of lady slippers, but one of mine had quite a few brown and indented marks on both sides of the leaves.
I first thought fungal disease and was so upset as it was a potentially great hybrid.
I sprayed and decided to see if the symptoms worsen before tossing. That's how much I loved the plant and it is not commonly available one.

Well, then one night as I was on a nightly snail watch, I thought I would peek into this plant just in case.
Guess what I saw!
A big fat slug attacking my lady slipper! I was so shocked but at the same time so happy to find out the cause of the troubled brown marks.
I picked the slug up and killed it right on the spot.

The done damage is going to be lasting scars, but at least no more marks are being made.

I doubt yours is slug or snail damage, but take a look at night just in case. You might be surprised to see a big snail crawling all the way up to the cane and attack the leaves. Just a suggestion.

[KristenReuel]

Woah. I haven't seen any pests on it at all, but I'll check tonight for sluggers. I also swabbed it for mites, but it came out clean.

What are the lowest night temps a den phal can take? I can keep it on my balcony.

I'm glad you saved your slipper orchid

[NYCorchidman]

I will have to see the flower shape to be able to tell, but in general it can take it down to low 60s or high 50s when kept dry. This is not recommended though.

The ones with more "antelope" influence ( very rough generalization but bigger plants with skinnier petals overall) need much warmer temperature as compared to the ones with more round flowers.

Cold damage will first occur on these guys by yellowing leaves and then drop. Then you know it is too cool and move them somewhere warmer, but try and keep them where the temperature stays above 65 if possible.

[KristenReuel]

These are the flowers

[NYCorchidman]

One of my favorite color combos on this type of plants! lovely!!!

That one has pretty much equal dose (or influence) of both so called phal type and antelope type.
As far as its tolerance to cool temperature, you cannot tell by looking at it, but I would keep it above 65.

I have a Chao Praya Gem which has the same color bombo, except the lip is much darker and the flower shape is more round. Well, that plant had been doing fine for a number of years and then earlier this year, it showed some funny indented markings with no color. They were rather white. I thought mites again. I freaked out and tossed the plant. I did save one tiny keiki which shows no such indentation. It will be at least a year or two before this thing flowers, but I love it and will see how it goes. Please no indentations! lol

---------- Post added at 04:08 PM ---------- Previous post was at 04:03 PM ----------

Also, water your plant.
Dry mix seems to help snails and slugs hide inside making it impossible to tell if they are present.

Often, they will get out on the surface searching for air when plants are soaked.
I soak my orchids when I water them, and this way, I belive I've killed many bush snails.
They either come out of the mix if they can, and if they are too deep down inside the pot, I think they just die stuck in there.

So, soak the pot and leave it in water for good half an hour and see if anything comes out. or, just water the pot normally. then check for slugs or snails at night. If you have the time and patience, check like every half an hour starting at dusk til quite late like 11. You don't know when they come out, although I find them very active midway into the evening like around 9ish.

Another thing you want to try, if you just watered it and do not wish to water again, is to place a slice of cucumber or carrot, even potato, on top of the pot.
Check often again to see if there's anything sitting three and easting the slice. You might be surprised!

[KristenReuel]

Ya, it would be a shame to have to get rid of it. Temps are hovering around 65 at night here in Ontario, so maybe I'll just let it take it's own chances outside?

I soak most of my orchids, including this one. Sometimes I forget about them for an hour haha. I have not seen any pests on this orchid, but I haven't looked closely when it was watered. I will do that soon. I will also check on it tonight, and try the potato.

The leaves do have silvery white gunk on them. Barely any, not like snail trails I don't think. It appeared when the leaves first opened, long before the indentations. And it's on the tops of the leaves, not on the bottoms where the majority of the indentations are. It's just a few tiny flecks of thin, dry, silvery white stuff.

The other bulb/cane (the one with the cut leaves) has no sign of the white fluff or the indentations, which is weird.

Thanks for your help with my mystery!

[NYCorchidman]

mites are high possibility. Some are nearly microscopic I read.

The one I tossed, well, two of them, one had only one of the new canes showed the symptoms, and Chao Praya Gem was like horrible!

If you have a separate room, why don't you keep it and just watch what happens?