Ugly Catt roots

[tinarae]

I got a young catt (4 leaves) on ebay a couple of months ago, potted in moss. I asked the seller if it needed to be repotted, she said wait until Spring & put it in my choice of medium. I took it out of the pot today, and most of the roots are spongy & brown. It's got 2 new roots starting, but they're still too small to reach the medium. 2 of the old roots are green about halfway down, then they are brown & spongy like the rest. Should I cut off the gross roots before putting the plant in bark? I've removed all the moss from around them, and the plant is laying on the counter waiting for instructions from me, I guess.

[tinarae]

Oh, PLUS, there's some sort of turquoise fungus on parts of the roots. Is there some sort of fungicide to put on this? Will the plant be okay out of it's pot until I can buy some tomorrow?

[Tim C.]

Sounds like your catt has a case of root rot.

Definitely cut off the brown roots before repotting in bark. I don't know if it's the "right" way to do it, but I've always cleaned my rotted roots using plain old hydrogen peroxide - something most people have on hand as it is. Just cut off the bad roots, and give the whole bottom of the plant a nice spray or rinse of peroxide. No worries if it gets onto the plant itself - hydrogen peroxide changes into oxygen and water once it reacts to a contaminant.

If you want an alternative, I think Physan would also take care of "cleaning" the rot and fungus out - but I have no experience with Physan, so I can't speak to it's effectiveness, only heard of people using it.

-Tim C.

[kiki-do]

Listerine is what I use. Plain not minty. Do you have any KLN root hormone? It's fine like that until you can get some stuff for it. It will probably like the air. I agree with Tim and cut off the black and squishy roots.

[buckie]

Root rot is most times caused by over watering, more orchids are killed this way than any other cause, let your catt dry out after watering, at least 3 days at normal temp, be more carefull when the temp drops.

Warren

[Des]

buckie , in my experience it is not overwatering that kills roots ,but spent media which is breaking down through bacterial action (a swamp in a pot)and the bacteria are there due to salt build-up in the media(too much fertilizer) . both the bacteria and the spent media produce toxic gasses. These gasses displace the oxygen within the pot and the roots will die from lack of O2. In matter of fact I have found that watering more often actually helps this situation for a short time as it flushes away these gasses and salts. However All this can be avoided by repotting your catts into baskets.

[buckie]

Yes Des, that is true, but it depends a lot on the potting mixture that people use. Each different mixture retains different amounts of water and fertilizer and as you know if you are using a mixture that retains water that can give you all sorts of problems if over watered. What most people forget is that in general most Catts grow in tree's in the wild where the roots get to dry out quickly after rain, transfer that to your Catts at home and there is little trouble.

Warren

[Ray]

1) The "turquoise fungus" is probably mineral buildup from the fertilizer.

2) Water, per se, does NOT cause root rot. Tissue has to die first, then it will begin to rot.

As Des alluded to, as a moisture-retention survival adaptation, epiphytic orchids have far fewer leaf stomata than do most terrestrial plants, so do most of their respiration through their roots. Anything that you do to restrict or eliminate their ability to "breathe" will cause them to suffocate and die, unless the roots are adapted to the specific environment. That is why it is possible to grow plants in water culture - once roots adapted for it grow.

The problem occurs when a root designed for one environment is "suddenly" exposed to another - as in watering an overly-compact medium, in which the bridging water droplets close the air pathways.

The cattleyas-in-nature example is a little oversimplified, as there are seasons when rains keep the roots saturated for months on end. Fortunately, their unresitricted exposure to the air prevents that from becoming an issue.

[nhman]

Ray, as always, elegantly stated, scientifically correct and to the point!
Remember, the environment indoors in the Pacific NW will have different qualities to the growing environment of orchids than from those outdoors in peri-equatorial regions.
Thus, a "simple" cross-walk from what orchids thrive on there to what they will grow well here is difficult at best.
That and remember, orchids still die in the wild too, it's not just us that kills them! (Tho I've contributed my fair share it would seem.....)

[tinarae]

Thanks for all the info, everyone! When the plant first arrived, I wanted to take it out of the moss first thing. I've cleared away all the squishy roots & repotted into bark. nhman, growing orchids here in the PNW probably does have it's own unique challenges that I'll have to learn the hard way! On the bright side, my SLC definitely has a bud inside the new growth!