Rotted roots

[Dollythehun]

As I was repotting this morning, I noticed the velamen (sp) was off some of my Maxillaria roots. (This is the topic of a future post). However, I just repotted it and went on to an Oncidium and saw the same thing, again, I potted and went on. There was no obvious mushy rot. I have often read to pot and that the inner 'strings' hold the plant in place. So, maybe a root discussion would help new comers. I know I could learn more.

[Mountaineer370]

I would like to learn more on this topic, too. I sometimes come across roots that have that section of string interrupting what otherwise looks like a normal root. I never know if I should cut it off at that point, cut the entire root off at its base, or just leave it alone. If it looks pretty good on either side of the stringy part, I've been leaving them alone.

[Roberta]

If there are a lot of good roots, removing the ones that have lost the velamen but have the stringy inner part looking OK is fine. Those old roots are still capable of hydrating the plant but aren't as efficient as the good ones. On the other hand, if most of what you have is the stringy part, leave them - again, they can help hydrate the plant by passive action (think of how water can go up a string) but also will help hold the plant stable when you repot. And keeping the plant stable is vitally important in giving new roots a chance to grow. If the plant wobbles, those tender new root tips can be damaged by abrasion against the media. So anything that helps to hold the plant is beneficial. If you have no roots at all, you can help the stability by tying a wire around the rhizome with the ends hanging down (fake "roots") but the old roots, if firmly attached, are better than the fakes.

[bil]

From what I have experienced and read, I would say that the golden rule is, DON'T CUT ROOTS OFF, no matter what.
Also, if you are saying that some of your roots are dying, then my immediate suspicion is that they have been starved of air/oxygen.

[nogreenthumbs]

This may be more than you folks want to know, but this has some really good info

Epiphytes: Distribution & Features (With Diagram)

Also, here's an interesting thread on roots here on the board

[Dollythehun]

I have lots of new roots on one, some new on the other but no rot. My maxillaria is supposed to stay wet ( per Andy and ISOP) so I just wanted to get this conversation started to help beginners. I was thinking practical (thanks Roberta) vs too technical. Roots 101.

[nogreenthumbs]

Originally Posted by bil

Also, if you are saying that some of your roots are dying, then my immediate suspicion is that they have been starved of air/oxygen.

THat was what I was thinking. If you potted the orchid initially, and there were no "strings", and now you are repotting and there are strings, then you need to rethink some aspect of your culture. Maybe the media, or your watering or temp or something. I think there may be a couple of types of orchids where you expect the roots to die back regularly. I think the Catasetums die back during the dormant period. I think I've read that the Cattleya die back, but I'm not positive, and I'm not sure if that's a rule or something that happens at certain times in the growth cycle. I believe it's also not unusual for roots to die due to a major change of environment (like repotting from one type of media to another, ie bark to s/h or bark to fwc, etc....

[Dollythehun]

For instance, my plant just went out side, which is a culture change. ( The point here is not MY plants, it's a root tutorial).

[Roberta]

Roots die on Catasetenae (but then, when you're potting them they're bone dry anyhow) On Catts, roots on back bulbs will die, but on p-bulbs with leaves hopefully they don't. For those (and most others) the roots should stay good for several years (growth cycles) - if they're dying prematurely, time to look at what might be causing it.

[Dollythehun]

I learned a lot about Catt roots and it has really helped a lot!