Repot, or not? Medium for Cattleya dowiana and Trichocentrum splendidum

[Catt Mandu]

I went to my local OS meeting on Sunday, came home with 4 plants:

Neolauchea pulchella (= Isabelia pulchella), mounted on cork - freebie!
Epidendrum radicans (blooming - freebie!)
Cattleya dowiana
Trichocentrum splendidum (formerly Oncidium splendidum, a mule-ear type)

My question is about the last two. The plants are both quite young, the Cattleya dowiana has pseudobulbs up to 1.5 inches tall, leaves up to 4 or 5 inches long. The Trichocentrum splendidum's longest leaf is about 3 inches. Both came from a vendor I know and respect, and the plants appear to be in great shape, good roots, and each has a new growth that is about half-mature (elongated but still flat, leaf not open, no roots emerging from the new growth).

So here is my question. Both of these plants are currently potted in sphagnum. And growing well in sphagnum! This vendor grows just about everything in sphagnum (greenhouse, of course, where moisture can be managed). The vendor advises that I keep growing these plants in the sphagnum. But, everything I have ever read about both of these plants is to grow them in medium that is very open and fast-draining. Decades ago, I has a T. splendidum that eventually succumbed to root rot and soft brown rot (I watered too often, most likely). I grow outdoors April through October, weather permitting, so plants can be exposed to prolonged rain (or prolonged dry, and heat). Indoors under lights the rest of the year.

My "gut" reaction is to re-pot into a coarser fast-draining material when roots start appearing on the new growths. I'm thinking of either planting in scoria (= lava rock), or a combination of cork chunks and charcoal. I am open to other suggestions, though. The pot would be either a terracotta pot, or a net pot set into another pot.

Any thoughts or suggestions?

[lijun]

i think the key of the mater is,.. if they are doing great and already got used of growing in the spaghnum, why change it,..

[zainal abidin]

For long term is not good especially outside the GH, the best remove some of the sphagnum dont injure the roots while pulling it, and keep the pseudobulb above the pot and cover whatever media that you going to choose, basically Catt is very tough plants and easy to grow, good luck.

[Catt Mandu]

Thank you for your suggestions! I am still considering my options, but your advice is welcome.

[clintdawley]

I grow Cattleyas in clay pots with spahagnum until they outgrow a 4" pot. In my experience, seedling catts benefit from the extra moisture when small. I've never had an issue with rot but I do let the moss get dry and crispy in the cool winter months.