Repotting oncidium/dendrochilum?

[Rykaerdoe]

Hello all,

I have been updating bit by bit my orchid collection. I have plenty of phals, they are great and easy to care. I think I got the hang of them - lots of roots, spikes and the sort.

I do have issues and questions about the two other kinds of orchids that I have. Oncidiums and a Dendrochilum Magnum. Both oncidiums are on a weird medium that seems like a very fine bark mix with some soil? It keeps the soil moist for quite a long time, as even during the summer, I only watered them every 2 weeks since the soil was always damp. Now on my new bulbs, I am getting accordion leaves, and I wonder if there might be a root issue.

Should I repot them on new bark?

On the other hand, the Dendrochilum dries way too fast, the media is always kinda "hard" and I have to water it twice a week.

The same question: Can I repot it on some new bark? Should I use something else? The bulbs are a bit shrivelled, so I would prefer to check the roots too to be sure all is fine.

[Ray]

Both plants need an airy mix, but it should hold some moisture, too. It sounds like the oncid's holds too much and the dendrochilum's too little, so why not shoot for something in between.

Both have rather fine roots, so a somewhat smaller particle size than that of your phals is probably advisable.

Just be aware that dendrochilums are notorious for disliking repotting, so you're going to want to baby that plant a bit afterward.

And yes, you're probably correct that there is a root issue with the oncidium.

[Rykaerdoe]

I guess that keeping too much water is the real issue. I'll repot asap the oncidium. I'll choose a little finer bark than I use for the phals and put some vermiculite and perlite there too. Let's hope they are not too far gone.

With the Dendrochilum, now that you mention its aversion to bing repoted, I might just keep on top of it and water it more frequently. Its true that the medium is quite compact, I'll try to check on the soil and "pry" a little to loosen the medium, hoping this isn't too big of a shock.

Thanks for your help!