These roots look dead to me, yet have green tips

[plantluvver]

I just unpotted an oncidium. I thought I had gone through and reported them all, but missed this one. The old medium was very broken down. I thought most of these roots were absolutely dead, they are wrinkly and dark. But I see green tips.

How do I tell whether roots are dead or alive?

[King_of_orchid_growing:)]

If in doubt do the "pull test". I don't think they're all dead. I can see that those with the green tips you're mentioning are alive, especially after you've watered them. The entire length of those roots have a greenish tint to them. There are some that are dead though.

[Optimist]

What would you do if they were dead? I see a few that look alive. Give it plenty of water, warmth, and filtered sun and you will get new root growth.

[plantluvver]

I would cut off the dead ones and repot in fresh bark. Isn't that what you are supposed to do? I need to learn at any rate, so I can understand what is going on with my plants.

Right now, NONE of my orchids has a vigorous root system. I am bummed that everything seems to be in the process of dying. (Some of my Phals are starting to grow new roots.)

I cut all of the roots off of some other Oncidiums, thinking they were dead. I wonder if I may have been wrong. I saw no green tips on those. Those were actually white,

[Optimist]

I personally do not see any reason to cut the roots off. They are a natural and perfect medium for the orchid. All orchids in the wild sit in nests of old dead roots with no other medium.

"I cut all of the roots off of some other Oncidiums, thinking they were dead. I wonder if I may have been wrong. I saw no green tips on those. Those were actually white,"

White roots are alive, but not in the process of growing.

Tell you what... don't cut any roots off. Orchid roots have a life cycle. they grow (green tips) they sit around doing their job (white) which is holding on to trees and also (more importantly) transforming water and sun into carbohydrates, and finally old and dead (various forms of holding on, catching rain for new roots, and keeping beneficial bacteria near the plant for the new roots. Cutting roots off (my opinion) puts them in a too-sterile environment that is detrimental... considering that they need the various "beneficial bacteria" that are in the air-- you will be reading up on those soon, I am sure.

[Orchid Whisperer]

I tell live from dead roots by feel, after they have been cleaned and rinsed, then allowed to dry.

Live roots will feel firm.

Dead roots will feel papery when dry.

When in doubt, assume they are alive.

[Leafmite]

If I have doubts about the health of the roots of a new orchid, I soak the roots for a few hours in distilled water. If they are alive, they will become nice and firm, as Orchid Whisperer indicates. Some will become green. I never remove roots unless I know for certain that they are dead.

[plantluvver]

Thanks for the advice.

I am considering trying water culture. Think it will be easier for me to see what is going on. And from what I read, this may be the best time to do this, since my plants need to grow new roots anyway.

Also, I don't have a good place to pot and unpot plants.

Would like some feedback.

[Optimist]

Besides what you see is velamen, the root is a fiber running through the velamen. In some cases, the velamen might be cracked, stained, or even burned by chemicals or too much fertilizer, but that does not mean the actual root is not working and taking up water.

[websherpa]

Originally Posted by Optimist

Besides what you see is velamen, the root is a fiber running through the velamen. In some cases, the velamen might be cracked, stained, or even burned by chemicals or too much fertilizer, but that does not mean the actual root is not working and taking up water.

This is an observation I made recently without really realizing what was happening. So perhaps a lot of people think of the air roots like I originally did.

In my Phals and Neos, I am now supposing the "velamen" is actually quite a thick layer and can exist and function even if "broken" but still attached by the root vein.

I had some roots with velamen rot but noticed that each end between was connected by a harder but extremely thin vein.

Until I decide to not cut, but repot and observe, I can now see (from it greening up, and continued growth of the root end), that the thin vein is actually the root and continues to supply the plant from further along the root. Being quite strong, by comparison, I would imagine it also serves the function of maintaining a hold on the plant's environment, and the velamen serves as a secondary moisture/growth storage system.

This is really just my casual observation, I haven't ever read or researched it that way before. But it came as a surprising revelation to me as I had always thought of the thick air roots as "the roots" - since the thin internal vein is easy to dismiss.