Roots.

[FL_GROWER82]

I know that there have been some root postings here lately but I need some help.

I adopted this orchid from work, which had endured some abuse and was in pretty bad shape when it got to me...it finally bloomed in July I was surprised by the color, the pinks and whites...and I had four blossoms with another spike now on the way.

Today, I repotted my orchid. I noticed that there were some white, green, and brown roots. I know that you do not cut anything that is basically green or white but, the brown roots were firm and looked healthy. There was no evidence of rot or anything like that.

There were a couple roots that were dead, slimy, and limp. They were definitely trimmed.

I am half tempted to de-pot and take a picture of the root system.

Any ideas on what the problem with the root system might be?

Thanks.

[cb977]

Firm brown roots?

Pictures might help us to help you

[Lagoon]

Aslong as the brown colored roots are hard and not mushy, you have nothing to worry about. These are just older roots, still able to take up water and fertilizers, even sprout new roots.

Welcome aboard

[FL_GROWER82]

Thanks Gloria!

That is a relief and very helpful!

I will also post some pics this evening.

Thanks again.

[reinbo15]

I agree, if the brown roots are firm, they are safe to leave intact. You will notice on the white roots (green when wet) that the tips on some will be a vivid green or a dark brown. Either color indicates fresh root growth, with the color being dependent on the cultivar.

[FL_GROWER82]

here are the orchid pics.

and

THANK YOU FOR THE TIPS!!!

[Lagoon]

Lookin' Good!!
Thanks for the pics

[Ray]

There are basically two sources of root discoloration - one is no immediate problem, the other is an indicator of serious issues.

If your potting medium contains bark, it is possible that tannin is being released, and that is pigmenting the velamen. While not an issue by itself, in extreme cases it is an indicator that the bark is starting to decompose rapidly, which suggests planning on repotting.

The other source of coloration, particularly if it's dark, are phenols released by a plant that is stressed. Phenols are phytotoxic chemicals, and are part of a plant's defense mechanism when being "attacked". That is usually an attack by pathogens or encroachment by another plant, but when under stress, the plant "knows" it's being attacked, but not by what, so pulls out all of the stops and tries to kill it. Unfortunately, those phenols are toxic to the plant, too.

I cannot say if it is an intermediate step or not, but I have had discussions with agricultural professors that explained that in what we typically see as "root rot", what actually happens is:

1. Something stresses the roots. That can be suffocation from water blocking a too-compact medium, extreme cold, etc.
2. The plant reacts by releasing phenols to combat the problem.
3. As the phenols don't relieve the true issue, the plant continues to try, and ultimately ends up killing it's own roots.
4. Now that they're dead, they begin to decompose.

I alway thought it went from 1, straight to 4, but those additional steps sound pretty logical to me.

[shakkai]

The photos really help here. You can see that one some of the discolored roots, new growth is starting. That's probably a good indication of whatever was causing the discoloration having been remedied. Good work!! This one looks like its going to like its new home!

Ray, That's a good reminder. I had read about phenols when I was reading up on the importance of air circulation and openings in the potting media - really don't want to trap these phenols in air pockets around the roots.

My question is if a dark discoloration is caused by phenols, does it inevitably lead to dead roots? Or would it be possible for the roots to become discolored, but if caught soon enough, the root would recover and not die off completely?

I ask because the little Phal I rescued from the supermarket had really dark discolored roots. I cut off the roots that were rotted and mushy, but many of the ones that were dark were still really firm and growing. Plus, if I cut off all the ones that were discolored the poor thing wouldn't have any roots left!!

If you need to get an idea of what I'm describing, there's a photo in this thread:
Supermarket Rescue

[Ray]

My understanding is that if the stressing agent has stopped, the plant discontinues exuding phenols, and while the discoloration may remain, it will no longer damage the roots.