Anyone grow rattail oncidiums (Trichocentrums)?

[Jeff214]

I have a Trichocentrum stacyi (or whatever the name is now...) that came potted in very coarse medium. Based on the medium, I was thinking that it likes drying out. It hasn't been doing too well, perhaps it's still adjusting to my conditions...

I was wondering if anyone else grows these rattail oncidiums and had advice on its culture.

Thanks!

[Roberta]

Notes from Charles Baker indicate that the species tends to be pendant, and is best grown mounted. If not grown mounted, then a hanging pot or basket with very open, fast-draining medium. However, it needs humidity, so frequent watering.

[Jeff214]

Thanks, I'm growing it hanging in a pot and watering everyday (dries very quickly in the afternoons). I don't think it's enough humidity here for this thing. I've mostly been treating it like a Vanda... which is doing fine here. hmm

[Roberta]

Maybe it just needs some time. If potted, the humidity from watering should be enough. Looking at the rainfall data in the Baker sheet, it may benefit from being somewhat drier (and bright) in winter.

I'm unfamiliar with the term "rattail" oncidiums... "Mule ear" is the nickname that I'm familiar with for Trichocentrums.

[estación seca]

Rat-tail Oncidiums like O. cebolleta or O. tracyi are epiphytes with long, thick cylindrical leaves that dangle down. I wouldn't think a pot would work, since the leaves are never upright.

They come from climates that are hot, and sopping wet in summer. There will be rain almost every day, and nights will be wet. They will be warm and almost completely dry in winter, though winter nights may be cool (rarely or never freezing.) Most grow on deciduous trees. They have bright shade under the leafy canopy in summer, then much more light in the dry winter when leaves have fallen. There may be occasional dew at night in the winter, so they shouldn't stay dry all winter.

My experience has been they take a long time to adapt to a new environment before they begin growing. Mine have taken over a year to do so. And if you let one get dry for too long during the growing season it stops growing until next year. Can you water a mount every day? Do you have a terrarium deep enough to hold it?

I would take your plant out of the pot and mount it to a piece of wood. Use minimal or no moss under the roots, and definitely no moss over the roots. Water it every day in summer, and weekly in winter. If you have a humid growing area, keep it there. If you don't, consider hanging it inside a deep terrarium so humidity stays up and the roots on the mount never get completely dry during the growing season. You will need to hang it because the leaves will grow down far past the bottom of the mount.

Edit: Your plant is not a Trichocentrum. Trichos should not be confused with the rat-tail Oncidiums. The two groups come from somewhat different rainfall / dew patterns. The rat-tails grow like mule ear Oncidiums, of which there are some in Mexico and Central America, but that latter name is often used to include Trichocentrums as well, solely on appearance to the eye. The mule-ear Oncidiums I've seen in Mexico grow in much more shady spots than do the rat-tail Oncidiums I've seen in Mexico.

[Jeff214]

Thanks for the detailed culture notes.

I currently have it hanging at a 45o angle and the juvenile length leaves seem to be okay dangling that way. I'm hoping to mount it once it gets acclimated to my growing conditions. I didn't want to shock it too much.

I grow a few things mounted in full sun here and they seem to be okay. I water once every day or two , and a deep soak on weekends. I wasn't sure if terete leaves = full sun. I've put in half shade to acclimate for now. I'll remember to increase light in winter.

Good to know that it requires heavy watering (mounted). So far it does seem to need a little more water/humidity than the other orchids I have. (It is about 40-50% relative humidity here + morning dew) Watering once a day doesn't seem enough for it. I've been soaking it in water for half an hour the last three days and it seems to have stopped going downhill (for now).

[estación seca]

It's not a full sun plant in summer, especially not in Texas. Bright shade under the leaf canopy. Almost none of the thick-leafed Oncidiums gets full summer sun.

[Jeff214]

Update:

After I started to water every day, the plant has begun to grow pretty quickly.