Phal. schilleriana (mostly)
 

Back in the Spring I decided to do a bit of experimenting, and bought six Phal seedlings (4 schilleriana and 2 stuartiana). The plants arrived healthy and happy, and were repotted in what I call plastic basket pots; half were left in fresh sphagnum while half in a mix of sphagnum and bark. My concern was less about water frequency and more about which seemed to overall excel. I used the basket pots so they would both dry quickly and also get plenty of air circulation to the roots, even with the sphagnum. Each plant is fairly small, with the largest presently having a leaf span of about seven inches, and so I figured that if they did well I might see flowers from them in 2018 or 2019.

Well, as experiments go mine could be called a failure. I can't really say that the potting mix has made a real difference. Each plant has produced plenty of root growth and both types of mix are drying at roughly the same rate in Georgia humidity. The plants themselves, though, are anything but failures. Each is now in spike and in bud (though one plant has just one bud), and the first schilleriana has opened its compliment of two flowers. One of the stuartiana has two spikes, one with 2 and one with 4 buds.

Here is the group of them together on their shelf in my kitchen grow-window (the stuartianas have the lighter buds):
http://i1361.photobucket.com/albums/...psekibsbxm.jpg

These two show the schilleriana, which in one is joined by a peloric Phal equestris that's been in bloom since Noah landed his Ark:
http://i1361.photobucket.com/albums/...g?t=1484262095
http://i1361.photobucket.com/albums/...pslcbdmpy1.jpg

Coming from such an immature plant, I think this schilleriana shows some promise, so I hope it continues to thrive as it has!

Those are beautiful flowers.
Your experiment tells me that you should try a completely different mix to have some conclusions. Why not one in sphagnum and another in "pure" bark?

I've got some other seedlings which, when ready to repot, I'm doing that way, though only 4 or 5 and not all such closely related species.

I forgot to mention in the original post that these flowers are about 1/2 to 2/3 the size of a recently bloomed and fully mature schilleriana. These plants somehow make me think of bonsai orchids.