is it time to give up? (phal stem rot)

[ambrosia]

it seems that one of my favourite rescues is in severe danger.

trimmed her dead roots about 2 months ago and converted her to hydroponic with a lot of drying out in between.

she seemed to be doing better, a new leaf grew and she had a flower spike! however the leaf stopped growing, and the flowers died quickly after blooming. she started to grow white mold, i panicked and cut all those roots as well and minimised water over the winter. now, it looks like stem rot.

what do you think? the leaves are limp and dehydrated. one side of the stem seems to be fine, while the other is progressively yellowing and there are some black spots. the roots are still alive, but attached to what seems to be a rotting stem. also, the white mold has returned and she smells somewhat ammonia-y.

i am willing to try everything to save her, she deserves it! right now my plan is to cut the stem up to the leaves and try to icu her into some new roots. however i am nervous because she is still doing okay right now, the leaves are not yellowing just dehydrated.

would greatly appreciate any advice! thank you!

[estación seca]

What are your temperatures? What kind of light does it get? Is it in pure sphagnum moss? What do you mean by hydroponic with periods of drying out? Do you mean you cut off all the roots, or only some?

Phals are warm growing orchids. They survive cooler than ideal temperatures when healthy, but not when sick. They will suffer when kept too cool.

The leaves are very shriveled. There were lots of good roots. That means it was severely underwatered for a long time.

I don't know whether it will survive. I don't ever cut off any roots. Sometimes dead ones fall off on their own, but otherwise most people can't tell a dead root from a living one.

If it has roots I would pot into something different, like large bark or LECA. I would water regularly and put it where I could give warm temperatures and high humidity. A heat mat would probably help.

[ambrosia]

thank you for the reply! she was recently moved in mid january, to a more humid & warm room. temperature in the room is always above 74 F, humidity typically around 30%, west facing window in the northern hemisphere.

when i cut the roots previously, i cut the ones that were completely dry/shriveled (light brown, when pressed it was like paper) and ones that seemed to have mold. she still had a fair amount of roots, all the ones present now are survivors from that purge (no new growth beyond the minimal that can be seen in the picture).

i previously had her in a small cup of water with the water level having one of the long roots with about 4cm inside the water. when the mold appeared, i restricted water severely (down to maybe twice a month at most with no medium to retain moisture) and i believe that is what hurt her.

i 'repotted' into pure sphagnum moss as per miss orchid girl's 'orchid icu' recommendations. right now my main concern is whether she has stem rot and that is why her still healthy roots are not absorbing moisture. the goal is to repot her of course but i am worried she is too fragile to adjust to a new pot right now. i am hoping to maximise her chances of survival before repotting.

thanks again!

[Fishkeeper]

Yes, watering a bare-root phal twice a month or less will definitely cause it to wind up in this sort of shape. Don't do that.

How often are you watering now?

Pure sphagnum is for plants with very little to no root system left, which isn't the case here. It's easy to rot a phal in pure sphagnum, when the phal has plenty of roots. Repotting is a good idea. Just be gentle with the roots.

[estación seca]

when i cut the roots previously, i cut the ones that were completely dry/shriveled (light brown, when pressed it was like paper)

Those were probably still alive. The central thin filament is the part of the root that absorbs water. The outer velamen component can turn thin and papery, yet the filament may still function. That is why I advise not to cut any roots.

Phals can do well in sphagnum if the grower learns how to use it. But I would agree with fishkeeper that you have a better chance if you repot now into bark or LECA. The severely wrinkled leaves may never plump up and look better; if the plant survives new leaves should grow out normally.

If you would consider a heat mat it would improve the plant's chances. 74 F / 23C is OK for a Phal but the warmer it gets the better they grow.

[Ray]

While you are trying to get the plant to recover, invert a clear plastic bag over it and the pot to trap humidity, and keep it warm and shady.

If the root system is compromised, it cannot take up water well, but that does not stop the plant from losing it through the leaves.