Dying roots on Cattleyas

[dbvogt]

Trying out orchids for the first time, I bought 2 Cattleyas in 3 in. plastic pots from a Gulf Coast, Florida grower. One is doing well with nice green roots at the top, the other plant's roots are withering and turning brown. Bottom roots in both are turning brown. The plants are in a garage in a south facing window that gets no sun but very bright light. Anyone know what causes the roots to do this? I water twice a week.

There are also 3 dendrobiums in the same window that were bought bare root at a recent orchid show. They're doing quite well in clay pots with healthy new growth. The last plant, an Ascocenda isn't doing anything at all, no growth but no sign of anything wrong. Any hints on the Asco?

[jaxorchidman]

Did you repot them when you brought them home? I always repot everything when I get them so I can see what conniption the roots are in and to make sure they are not in rotting media. Good luck!!

[Anisa]

You might have a root rot. You dont say what medium they are in or how big they are, but they might not need to be watered that often. What is air moisture in your garage? Pictures of plant and roots would be very helpful.
About Ascocenda.... sometimes new plants sulk for a while then snap out of it. You might want to try to move it in a different location.

[Eyebabe]

Sounds like rot to me as well. The plant may have been diseased when you brought it home. Especially since the other is fine under the same conditions.
You also need to check the media. The troubled orchid's media may be decomposed and it could be holding more moisture. Clean it up and repot. You may opt to treat with some Physan or Phyton 27.

[Orchid126]

A south facing window with no sun and only bright light is not bright enough. Cattleyas need sun, at least for several hours a day. How far away from the window is the plant? Light drops dramatically for every inch away from the source. Can you put it closer?

All the water and fertilizer in the world won't be enough if the plant isn't getting enough light to stimulate it into using them.

Also, how good is the drainage? Slip the pot off the roots and check if the drainage holes might be blocked somehow. Cattleyas like to dry out before being watered again. As Anisa asks, what medium are they potted in?

[dbvogt]

Thank you all for the replies. The pots are tight up against the glass, drainage is very good. The media is some sort of bark, no charcoal or perlite and it doesn't look decomposed. I didn't repot but perhaps I should move them into clay with a better media. Is a 4 inch clay pot too big?

I'll check on the chemicals. I've uploaded a photo of the two together but this my first post and I'm unsure where it goes. Note the dead roots at the bottom of both but the top roots on the right-hand plant are healthy, those on the left are not.

[nenella]

Hi, IMHO; If your Catleyas are in plastic pots and your asco is doing well in clay I would definitely re pot the catleyas into clay pots. If the roots are mushy it is because they are not drying out fast enough.. Keep us posted & good luck!

[johnblagg]

ok how warm is it where you are ...pots against window if it is cold at night would not be not good

[Eyebabe]

Originally Posted by dbvogt

Thank you all for the replies. The pots are tight up against the glass, drainage is very good. The media is some sort of bark, no charcoal or perlite and it doesn't look decomposed. I didn't repot but perhaps I should move them into clay with a better media. Is a 4 inch clay pot too big?

I'll check on the chemicals. I've uploaded a photo of the two together but this my first post and I'm unsure where it goes. Note the dead roots at the bottom of both but the top roots on the right-hand plant are healthy, those on the left are not.

...umm they BOTH look happy to me

[dounoharm]

too much water....twice a week for catts is too much...repot into clay if you can, clay works great with catts, pot em tight with large bark chunks....and more light please!