Is this overwatering? Overnight every leaf dark yellow!

[Pynn]

This DenPhal was so happy just a week ago -- it had loose buds about to open! All the buds dropped, which I thought might have been too much sun or an odd draft (I keep it near a southeast window).

Then just this morning it looks like this. Is this overwatering? The media seems pretty fine-grain, but I thought that was just peat moss, not decomposition. I water it once per week. I have many other DenPhals with no issues.

[estación seca]

What are the temperatures and humidity? The roots look good.

[SouthPark]

Originally Posted by Pynn

which I thought might have been too much sun....

Hi there Pynn. You mentioned that it's kept near a south-east window. And you showed a photograph of your plant being behind that window. And the light appears to be filtered by the window.

What led you to mentioning the possibility of 'too much sun'?

Does this mean that the light can get very intense through that window? Or did you take the plant outside to get some direct sunlight?

One leaf has been cut too. Was that cut due to fungal attack?

How long have you been growing this plant for roughly? And has it been sitting in that same spot behind the window for a relatively long time? And what is your watering method? And how much water is given when you do the watering?

You mention you have many other denphals with no issues. That is good.

Maybe you can inspect the potting media of this particular plant to see if there are any fine white filaments/hairs/growths due to natural fungus - which don't attack the plants - but can cause the media to not accept water too well. That's only if you can see whitish fungal growth through-out the media. If the pot always feels light after watering, then renewing the media might help.

[Pynn]

@estación seca, temps are stable 70-75 all day, humidity is on the low side, usually around 40%.

@SouthPark, it's too cold to go outside in PA this time of year! I actually keep it a few feet away from an unfiltered window, where it gets about 1 hour of direct light a day around 11 AM. If anything I think the light is a little to weak here in winter. The leaf was cut months ago, I had under-watered a few of my dendro's and the tips started dying back. I've had this plant for about 2 years, most of the time I've kept it in a different room but same exposure. When I water, I'll use the sink hose and run it through briefly until it starts running out the bottom -- once a week. The media shows no signs of fungus. It's a bit on the stodgy and heavy side after watering.

Thanks for the help and thanks for the questions guys! I'm still dumbfounded by this one.

[estación seca]

That happens with Den phal hybrids when they are kept too cold or not given enough water.

[Leafmite]

Wow. I have no idea. My two Phal-Dends are getting cold night temperatures in the sliding glass door and are okay with this. Daytime temperatures are higher as the T5HO lights warm everything. If your temperatures are staying warm, I do not think that it is the temperatures causing this. The roots look good.

[OrchideeNormus]

Just throwing this out there..I really don't know that this could make a difference at all. What is the rock in the pot with it? Is it possible it's giving the plant a little too much of something maybe? The only reason I thought to bring it up is because I know I can't put certain rocks in my aquarium because they do something to the water that would hurt my fish and plants. It's usually the rocks that are pretty and sparkly like that that I have to avoid too. Just a thought...

[Pynn]

Originally Posted by OrchideeNormus

Just throwing this out there..I really don't know that this could make a difference at all. What is the rock in the pot with it? Is it possible it's giving the plant a little too much of something maybe? The only reason I thought to bring it up is because I know I can't put certain rocks in my aquarium because they do something to the water that would hurt my fish and plants. It's usually the rocks that are pretty and sparkly like that that I have to avoid too. Just a thought...

Maybe, but probably not :/ It's a chunk of granite I put in there as soon as a got it to weigh it down. Topsy-turvy son-of-a..

[aliceinwl]

It looks like only the leaves on one cane went yellow? It also looks like the cane itself is yellowing. Maybe the healthy roots are associated with the non- yellowing canes and some kind of infection got started on the yellow one. Maybe see if anything looks amiss at the base of the yellow cane?

Cold could still be an issue. Is the temperature by the window actually staying above 70? Not all hybrids are created equal. I’ve seen a wide range in how much cold my various different Phalaenopsis hybrids can take. Maybe this particular Dendrobium phalaenopsis is more sensitive than your others?