What went wrong?

[ang709]

I acquired my first Cymbidium in Feb. A couple leaves had black tips. Otherwise, it looked healthy and had three new growths. In the warmer days of March I repotted and discovered that the root mass was surrounded by rockwool while the rest of the pot was filled with bark. Still, there were many healthy roots. I used the same pot (it was the only one I had that would properly fit the roots), but I disinfected it first. I used bark as the medium, have been watering once a week, and only fertilized once in this time, but something went wrong.

All the "happy honey" disappeared. More leaves have black tips. One leaf turned yellow. Now all the leaves have gone limp and another one is turning yellow. The back bulb turned mushy and stinky, so I removed it. Upon doing so, I discovered some bad roots, and so unpotted the orchid. More than 2/3 of the roots had turned soft with the velamen papery and peeling. I cut off those roots and put it in a smaller pot with new bark.

Any ideas how it went downhill so fast? Could it be the pot was not as thoroughly disinfected as I thought? Could the changing from rockwool to bark be the culprit? Something else? Also, I'm guessing it would be better to just let the plant settle in and recover this year and that I should not try to induce blooms by giving it cool nights later this year. Any thoughts on that?

[Cjcorner]

I have an oncid that was having major problems. I repotted it into a very airy open clay pot, placed a layer of coconut fiber in the bottom, placed a small amount of fir bark into the middle, placed the oncid on top of that and then added coconut fiber to the top and it has really taken off. There is a new growth coming along fast and the roots are growing nicely. They just needed way more air movement. I'm guessing bark holds the water too long and the thinner roots need to dry out faster.
Hope this helps
Connie

[wetfeet101b]

What are the growing conditions after repotting?
Light / Temperature / watering schedule / indoors or outdoors, etc.

What did you use to disinfect the roots during repotting?

Cymbidiums like to stay moist and they drink up a lot of water. With a pure bark medium, weekly watering may not be sufficient depending on where the plant is located. Specially as the weather warms up.

The disinfectant chemical might also cook the roots if it was mixed too strong.

[ang709]

Air movement is something I think I need to pay more attention to with all my orchids. I had problems with a Den because of that.

Sorry, let me clarify about the disinfecting. I don't think I put anything on the roots the first time. They were a tangled mess, but most were still firm. I wasn't overly worried about them at the time. It was the pot I disinfected before re-using. This time (last night), though, I treated the plant with physan, but it was mixed according to the instructions.

As for conditions: It's been sitting in a window with south eastern exposure. The room is almost always low to mid 70's. Humidity is no doubt low. I was watering literally once a week-each Sunday. I thought I'd start with that schedule and see how it went. I was afraid of doing it more often because the pot was so deep. Now, though, it's in a regular size 4.5 inch pot.