Help!! Can you tell me if these Rhynch. are rotting or is it normal?
 

I read that it is normal for an older pseudo bulb in Rhynchostele to shrivel and die if the newer pseudo bulbs and roots are not affected, but I`ve just had a Phal die of crown rot and now worry about anything that looks off in any of my other orchids.

Pics ending 7-13 are the Rhynch Rossi x Od. Picotee plant.
Pics ending 12, 13 & 14 are Rhynch. Rossi plant.
Both have new growth.

What do you think about these two? Are they rotting or is this normal? Do I have reason to worry or am I just being paranoid?

I don't think it's rotting. Regarding the pseudobulbs that are turning brown, are they wet and squishy? They don't appear to be (in fact everything in your photos looks like it has been kept very, very, dry for far too long). I believe what's going on here is that your plants are cannibalizing the nutrients and moisture in the old pseudobulbs as a last-ditch measure to spur new growth, causing the decline of the old bulbs.

How often do you water? How long have you had these plants? I'd recommend you either begin watering much more frequently or otherwise try repotting them into a more moisture-retentive medium. Moss, for instance, might be a great choice, especially since your climate (in Guadalajara!) is so hot and dry. Best of luck!

Claire

Also--have these recently been repotted? I can't see any living roots in these pictures and was wondering if you knew what the state of the roots were when you last potted these up. Could be that all the roots are dead, due to either over- or under-watering. That could definitely be causing the desiccation and dying pseudobulbs you see here.

I just checked the roots, and most of them are dried up. They do have some healthy roots under the new p-bulbs though. Do you think I`ve been underwatering then?

Oh, and the affected bulbs are NOT squishy at all. They are hard.

I water three times a week in winter (dry season) and twice a week in summer (rainy season-rains every day). Our max. temp. is 80F these days, with 50 to 65% Humidity when it`s not raining.

Yup. It's possible that even with the watering schedule you describe (which would be sufficient for a lot of folks growing orchids like these in bark), and your humidity, that your plants are drying out too fast. When you water, do you make sure that the pots are really drenched, with water running thruough the pot? I ask this because large barks chips in particular almost seem to repel water once they've totally dried out...you really need to soak the bark thoroughly when you water, possibly watering it again after a few minutes to be sure that the bark has actually gotten moist.

Bright light and high air movement also cause your plants to require more moisture. I grow mostly Cattleyas, and usually pot them in pure moss because I grow them in nearly full sun with excellent air movement. Bark simply dries too fast for me, and I killed a lot of plants in bark by underwatering before I knew how to water plants in that medium!

Try to up your watering frequency, and if you're feeling adventurous try potting up one in a different medium to see if it does better. Even a finer grade of bark would probably help you, I'm thinking.

I`ll repot them with some moss as I do my Phals then and water them a little more frequently until they get back on track. Thanks for the help. I`ve not been able to sleep worrying about them since I lost a Phal yesterday to rot....

I agree with everyone who said these look like they're not getting enough water. I would definitely repot these in a mix that retains more moisture.... a good indicator that they're getting enough water is that the pseudobulbs should be plump and not wrinkly.

Good luck!

Just a suggestion, I think that pot is too large, especially if you're going to be using moss. I would move it to a much smaller pot with a mix that holds a little more moisture. Between waterings if the mix is getting dry, a little misting around the base of the psuedobulb often encourages new roots.