Pleurothallis allenii potting advice needed
 

Next on my list of plants to pot is my Pleuro, which is the reason I decided to take the dive into Orchids to begin with :)

I have this, which I'd like to use as a terrarium, as the room I'm keeping these guys in has ambient humidity between 30-50% and I know pleuros like it moist.

https://i.imgur.com/SEGtgGB.jpg

What is it? It's a betta bubble (disclaimer - if you have a betta fish, please don't put it in one of these. they are terrible for pet fish).

This one is about 23cm diameter. A tube of chapstick has been included for reference.

My pleuro is blooming size, but will fit physically inside this bubble terrarium. According to my culture sheet this species maxes out at about 6" tall. Mine is getting close to that already.

So my questions: Do I need to upgrade it to a bigger bubble? If so, I do have a larger one, but it currently has a Dendrobium in it. And, what method of potting do you recommend to keep the humidity where it should be (75-90% according to my Baker sheet)?

My tentative plan was a base layer of lava rock, a small piece of bark sitting on top of it, surrounded by very wet moss, and then moistened moss around the pleuro's roots.

Yes, go bigger. The last allenii I had was in a 2" pot. While each individual growth was about 6" or so tall, the plant had "mounded" as it grew, and was about 8" tall and about 10" in diameter.

Great! I'll just switch them, then. The mystery Dendrobium can go in this one since the humidity requirements are lower than the pleuro :)

Any thoughts on planting media?

Mine was in chopped up tree fern, but I watered frequently. I imagine it'll be more difficult in such a sphere, so I'd probably go with a "blend" of coconut husk fiber and sphagnum. - very airy, but moisture-holding.

Would bark work instead of the coco fiber? I have tons of it lying around XD

If the bark is fine grade, and you can mix it with the sphagnum well, it ought to be OK. I'm afraid that coarser bark tends to give pockets of dry and the moss becomes pockets of "sop", rather than a mostly uniform blend.

You can always take a hammer to some bark.

It's pretty fine grade bark, so I think I'll give it a shot. Thanks!

So, this is what I ended up with (I needed something pretty)

https://i.imgur.com/dgmtTbV.jpg
https://i.imgur.com/UQn9iW6.jpg
https://i.imgur.com/hkQ8WG3.jpg
https://i.imgur.com/m49NIqG.jpg

It's not quite done yet, because I'm waiting for the ugly bale moss to rehydrate before I cover it with bark chips.

My plan is to mist the bubble every day with distilled water and make sure there is nearly always water in the drainage layer to keep the humidity up.