Root rot after repotting

[Sandy]

Hey guys!


I have noticed that the roots of the repotted orchids, begin to rot after a while, they become black. Since they are in semihydrophonics I do not overwater the orchids, and even the roots that are on the surface get those black rot-spots here and there.

I dont understand why?

I have found out that the KLN isnt really helping out with the root growth either, it's like nothing happens?

[Lene Th.]

When you repot into S/H, or any different culture than the chids are used to, the old roots will eventually die/rot.
The old roots are used to the old culture, and the cells are adapted to this. When you repot into any other culture, the cell have to re-adjust themselves, and the old roots cant change cell-structure, therefor they die. The new roots grow cells that are adapted to the new culture, and thats why it is so important to wait till the chid has active root-growth before a transphere into something new.
Some chids needs longer time then other to re-adjust as well....
What kind of chids have you re-potted? Did they have any new root-growth before you re-potted?
And how long has it been since the re-pot?
Ray has some really good advices and explenations to this, and a hole lot more about S/H culture, on his site.... Its sticky on top of this forum.

Sometimes, the roots are adjusted to wet culture, as mine were (im a heavily waterer...), and then the adjustment seems to be a bit easyer on the chid, than if the roots are adjusted to a dry environement before the repot...

Give the chid some time, take it out of bright light for a while, and give it time to adjust...

A pic could be helpfull as well.

[Sandy]

Originally Posted by Lene Th.

When you repot into S/H, or any different culture than the chids are used to, the old roots will eventually die/rot.
The old roots are used to the old culture, and the cells are adapted to this. When you repot into any other culture, the cell have to re-adjust themselves, and the old roots cant change cell-structure, therefor they die. The new roots grow cells that are adapted to the new culture, and thats why it is so important to wait till the chid has active root-growth before a transphere into something new.
Some chids needs longer time then other to re-adjust as well....
What kind of chids have you re-potted? Did they have any new root-growth before you re-potted?
And how long has it been since the re-pot?
Ray has some really good advices and explenations to this, and a hole lot more about S/H culture, on his site.... Its sticky on top of this forum.

Sometimes, the roots are adjusted to wet culture, as mine were (im a heavily waterer...), and then the adjustment seems to be a bit easyer on the chid, than if the roots are adjusted to a dry environement before the repot...

Give the chid some time, take it out of bright light for a while, and give it time to adjust...

A pic could be helpfull as well.

Hey Lene!

Thank you for the detailed eplanation! I always buy chids where I can see that there is new root growth, but still it takes ages for them to adjust.

I have also noticed that the ones that came from a relatively dry environment rot first, and the ones that came from a moist and wet culture seems to thrive rather well.
I only have phals at the moment. It's been a few weeks now, so I guess I have to have more patience.

I am just worried that the roots will rot and then hit the plant before there will enough new rooth growth. I actually lost two phals because of that, the new rooth growth is "delayed". I might up the KLN dosages a bit maybe?

But you mentioned that all the old roots will rot/die, doesnt that mean that I have to take out the plant from the pot and then trim away all the rotted roots at some point?

[DelawareJim]

Sandy, I'm having the same problem with 2 new orchids lately (a Phal. NOID and Blc. Chia Lin 'New City' I rescued from Lowes) and it has me perplexed as well.

Using dehumifier water and MSU per directions, plus KLN, in a shady location to adjust, presoaked prime-agra in dehumifier water for 3 days with water changes, 40-50% humidity, the works.

They're cranking out new roots like crazy, but each time the new roots touch the prime-agra they turn black and die within about a day. Very frustrating.

There has to be some chemical/fertilizer component on the LECA surface that is affecting the root cells causing them to die.

I just completely flushed them both with dehumidifier water only and will try that by itself for a while to see if they come round. If not, then I think it must be something from the dehumidifier condenser coils that is contaminating the water and is being absorbed by the roots that's affecting them.

Cheers.
Jim

[Ray]

In the manufacture of any clay body - bricks, pots, tiles, toilets, LECA, etc. - chemicals known as "binders" are used to give the unfired article "green strength" so it can stand up under its own weight. When being pelletized, there's a lot of it to allow the clay to roll up like little snowballs.

Upon firing, some of those binders remain in the body as manufacturing residues. Additionally, to keep down dust and cool the post-fired pellets, they are often sprayed with water, and I'd guess that to be non-potable, containing who-knows-what.

When you water, those minerals dissolve and are transported to the top surface, where all of the evaporation is occurring. There, they precipitate into the crystals you see, and they can be toxic to the roots.

The best thing to do is to soak and rinse the medium very well before use, and if you didn't, or still have the problem anyway, water very heavily and frequently with plain water for the next few weeks, as that'll help with the flushing.

[Sandy]

Thanks guys,

Gosh it is really frustrating, Im loosing more and more chids to the black rot. Next time I will wait a while before I repot them, despite new root growth. I think I will have to water them a lot and make them used to lots of water before repotting, Im trying this experiment right now actually with a new orchid. And ofcourse, extra-rinse the LECA..

What should I do with the ones that have rotting roots, but still have some healthy roots, and where there is a chance to save the plant? Should I repot it back to regular bark compost etc?

[Ray]

The fastest conversion to S/H takes place not with roots that are in a new growth spurt, but with new roots, just starting to grow from the plant.

In an existing root, the new growth may grow in a form compatible with the new environment, but the parts that already existed cannot change, so may still die, taking the rest of the root with it. With a brand-new root, that does not happen.

Sandy, temperature can play a big roll in acclimation, as well. What minimums are your plants seeing, and what type of orchid are you referring to?

Also, K-L-N is not magic. It does not affect existing roots, but affects the plant, increasing the tendency for it to grow roots. It does not guarantee that it will.

[Sandy]

hey Ray!

I have only phals at the moment, I have a pic of one of them below. The root pics are from 2 different chids.

Oh dear, what a mess. The root rot seems to begin just where the root grows out from the stem, and the roots themselves have a few black rot spots here and there further down. I have specifically potted the plant in a way which makes the stem not completely covered in LECAS but half way so that that there is good air circulation, but still the stem is mostly affected.

They plants are placed in semi-sunny areas on a window sill. I have a picture of them and my windowsill one of my old posts.
Most of the orchids have begun to grow new leafs and a few have started to grow small roots from the old roots. But they still rot in the meantime, and rotting into the stem, I dont get it? I must do something wrong, really wrong.

The temperature is 75.2 F most days, they are placed in my living room.

I really want to succeed with my chids






This one above has a little baby root growing out up there, small white spot



So what should I do with my beautiful pink dotted phal which barely has any roots left and rot problems? I had to trim it down pretty much... The first root picture shows the roots from that phal.

[Lene Th.]

First, i dont think those roots look bad, theres new growth rigth from the plant, and as Ray explained thats a good thing! At the time they are still quite short, but they will continue to grow, and get bigger.
Now to the sad part... I would cut away the flower-steem... This to encourage the chid to put the enery into producing more roots.
Theres a lot going on with this chid, you say its producing a new leaf, and it has been re-potted not long ago, and then theres the flowers. It migth still try to produce more flowers on this spike, as long as the spike is still precent. When cutting this spike, you alow the chid to use its energy where its needed...

Then, as long as the rest of the conditions as air-sirculating, humidity, tempratures are rigth, i would just wait, and let mother-nature do her way.

[Sandy]

Hi Lene!

Yes, I agree, the rotting is not that bad, yet. But my previous orchids looked the same and then the roots and the stem completely turned black after a while, and Im afraid the same thing will happen with this one. What disturbs me is that the stems always get so badly affected, even more than the roots.

Yep, I could cut away the stems (there are two on this one) and try again. I read that a shady position is good to encourage root growth? All the fertilizers I have added have just made the chids produce new leafs and other stuff, making new roots doesn't seem to be a priority..

Gosh, I thought this s/h transition would be easyyyy