Cut “dead” roots?
 

Just bought a rescue orchid from Lowe’s, it doesn’t have a good root system after removing the decay, theres roots without velamen, do I cut them or let them be so that it can absorb more water?

The orchids also dehydrated which im guessing is the cause of rootrot

I suggest leaving them - you have cleaned off the rotted stuff. Those "cores" of roots are actually functional, and can hydrate the plant, even if not terribly efficiently. (The dehydration was caused by root rot, not the other way around) They also serve to anchor the plant firmly in its new medium so that it doesn't wobble - really, really important. You can clean them up at the next repotting in a couple of years, by which time, if your efforts pay off, the plant will have good new roots.

Roberta, Do you have any reference articles about the vascular tissue remaining viable? You are not the first person to state that, but I’ve yet to find anything that backs it up.

Not picking sides here, although I have always been told once the velamen rots the root is useless in regards to nutrition absorption. However, in this situation, the remaining root cortex could be beneficial in providing stability to the plant after repotting.

I don't see any "sides" here at all. I'm just trying to discern the facts.

Velamen is merely the outer layer of dead cells anyway, acting as a "sponge" to hold water. I have read that it also actively traps nutrient ions, as well.

The trouble (in my mind) is that there is a lot more than velamen lost when roots rot, so I wonder if the xylem and phloem can remain functional.

http://cdn.biologydiscussion.com/wp-...18_thumb-4.jpg

Just trying to learn...

I don't have a reference, but have heard this said by enough experienced (and professional) growers, that I have to suspect there is some truth in it. As I have heard it described, some water can get up the root by capillary action (think "wet string") Certainly not great, but possibly better than nothing. The stability part is clear - if those roots are still firmly attached they can provide that much at least.

Unless they are contributing to the rot, ie, adding more dead material and clogging air flow, I see no reaso. To cut off what is there. It adds stability and I have seen “dead” roots grow new root all the time (mostly on Vandas but woody brittle roots with new white roots growing out of it.

Gonna hafta say "Nye" to that. "Experienced and professional growers" have also said that "orchids have to dry out between waterings" and that "semi-hydroponics won't work", both of which have been proven to be untrue.

At this point I'm not discounting the possibility that they contribute more than just mechanical stability, but I am skeptical.

I'm following this one closely. I would also like some Nyeintific research on that one, if any is around. I surely understand the stripping off rotten velamen, I understand the stability issue. I too have been skeptical about what that little white string may or may not be doing. A lot of experienced growers also do other stuff I may or may not do or agree with. For example, I whack away at ugly leaves that bother me. A lot of experienced growers say not to. But I raise plants by the "gut feeling" for the most part. Always have. Is this kind of like the peroxide conversation we had a ways back? As far as professional growers go... a whole different ballgame in my opinion. If professional grower means someone who grows/produces for profit. Way out of my culture or desire.