Phal. cornu-cervi with yellowing upper leaves
 

Hi all! I hope everyone is having a great start to the autumn season (at least for those of us in the northern hemisphere). I'm back with another orchid issue. :blushing:

Recently I purchased a phal. cornu-cervi var. chattaladae. Having had a bunch of the common store-bought phals for a few years, I figured I'd try it out with a species phal.

Fortunately it arrived in pretty good condition (although I've never seen this type of media before-it's like a bunch of small sticks. Water flows well through it so I wasn't too concerned initially):

https://lh3.googleusercontent.com/-D...2019-10-08.jpg

Unfortunately, last week its 2nd-most recent leaf (excluding the leaf currently growing from the crown) began to pale before going yellow and dropping:

https://lh3.googleusercontent.com/-6...2019-10-08.jpg

https://lh3.googleusercontent.com/-l...2019-10-08.jpg

https://lh3.googleusercontent.com/-P...2019-10-08.jpg

The leaves below it on the same side of the orchid appear to be headed towards a similar fate as well.

https://lh3.googleusercontent.com/-X...2019-10-08.jpg

https://lh3.googleusercontent.com/-f...2019-10-08.jpg

Fortunately, the most recent leaf (on the left in the picture above) still looks dark green and relatively healthy. After unpotting it and checking over the root system, it looks pretty good as well (to me anyway):

https://lh3.googleusercontent.com/-n...2019-10-08.jpg

Right now I have it laying bare-root in an empty peanut container. I give it a bit of water daily and let it sit for about 3hrs before emptying it out.
It sits in a west-facing window, so I'm pretty certain sunburn isn't the issue. Temps & humidity tend to fluctuate in my room, but it tends to stay around 65-72°F (although it may get colder directly nearer the window) with around 50% RH. I've been checking the stem daily but I've yet to see any clear signs of stem rot.
Any idea on what could be happening/what to do to ensure the phal stays alive? I really love the cornu-cervi's blooms and I'd hate to have this one die on me.

First, I think the plant will be fine... I have had the same thing happen, and as long as the crown, where the new leaf is coming out, is OK (and yours looks fine) it'll continue to produce new leaves. I suspect that there was something in the plant's history that made it lose leaves, that has been corrected. The mix looks like it is sphagnum with some additives or some kind of wood fiber. You're quite right to want to switch it to something that you know.

I have had good results with Phal species (including this one) in wood baskets with loosely-packed sphagnum (just enough to hold the plant), I have also used bark in those same baskets and that works too. (Downside of bark is that it falls out of the slats). If you use a plastic basket, might be easier. But I have had much better success with species Phals in baskets than pots - the roots escape, and that's their natural habit. (My completely unproven hypothesis about this is that the "domesticated" hybrids have been living in pots for generations and are happy that way but the species are closer to their jungle origins. Pure speculation, however) If this were my plant, I'd put it in a basket with loose sphag. Water well, then repeat when the sphag is barely damp. That approach will let it get the wet-dry cycle and air that it wants. Probably best to keep it back from the window so that it doesn't get too cold - those temperatures are OK but you don't want to go lower if you can avoid it.

I think the primary issue with that plant is that it's not getting enough water in that medium with your growing conditions and watering habits. You need to find a medium that holds more moisture while staying airy.

It looks to me like that's either osmunda or tree fern chunks. Stealing from Roberta's suggestion, if you mixed it 50/50 with sphagnum, it might work great in that air-cone pot.

GoldStar, what is your usual preferred potting medium for your other orchids? The stuff in the picture looks, to me, like mostly shreds and slivers of wood. Some of it could be sphagnum, but I can't quite tell from the picture.

Roberta and Ray have a lot more growing experience than I do, and their advice would be well worth following, if you're able. I'm someone who is not comfortable with sphagnum at all. I have trouble being able to tell when it needs watering. I have much better luck with Orchiata bark, but each of us will develop our own preferences for what works best for us as time goes by.

I have a cute little Phal. cornu-cervi that I got in the spring of this year. When I got it, I repotted it into a clear plastic slotted pot with small/medium Orchiata. It's doing great and has been in constant bloom. All of my orchids live on my dining room table or a smaller table in my bedroom, all year round, and I have to be very picky about containers. I can't have anything that allows media or moisture to escape onto the table. So I use the clear plastic slotted pots with a clear plastic saucer underneath that has indentations to catch excess water so the bottom of the plant pot is not standing in water. Yes, the roots do end up growing through the slots in the pot, and I have to cut the pots when repotting, but I figure it's worth losing a pot that was a few dollars or less, for as infrequently as repotting is needed.

I like the looks of the plastic baskets and have thought of trying those, but I'm afraid the smaller bits of my media will easily come through the holes. Of course you wouldn't have that problem with sphagnum.

In your photo, it looks like you are using a Styrofoam bowl as a saucer and that you have some of the media in it. It also appears that the only drainage holes in your pot are at the bottom, so I wonder if the combination is making it hard for the root system to get enough air flow and dry out after watering. (I'm not saying you want it to get really dry, but it should get a bit drier between waterings.)

The roots on the plant look great! I think with repotting it into a more appropriate medium, whether you prefer bark or sphagnum, and making sure the pot has lots of air flow, it should recover.