Phalenopsis dying (mouldy aerial roots) - help!

[Shadeflower]

I had similar concerns to mountaineer.

The holes have been blocked so are of no use when trapped like that.

Now I do use cache pots like that more than most and it can be done but the substrate has to be the airiest and fairly chunky.

That would be my concern. It's always a matter of finding the right balance, if there are lots of air holes then the media needs to be more fine, the smaller the pot , the finer too and vice versa the less airy the pot the airier the substrate needs to be, a big pot will not dry as fast so the subtrate needs to be bigger.

Aslong as the right balance is found then endless combinations can be used.

But to me on that picture from my experience I do not feel the right balance has been met there.

It's a sealed cache pot with a fine bark media (compact)

The wick is no good either, it needs to be either a microfiber cloth or a proper plant wick, a little piece of string is no good. It will not wick enough, the pot will get too dry and will need as much watering as a regular pot but it will stay too damp and compact at the bottom.

I don't want to say it can't be done but I would be adding the biggest sized lecca I have at the bottom of the pot to give it that aeration it needs and use a wick that wicks well.

[tmoney]

meh, looks fine! perhaps a slightly more airy cache pot as others have suggested. but whatever you do, personally i wouldn’t try to repot again for another year unless it’s an emergency situation. let it be and see how it responds to the changes you’ve made.

totally my beginner observations, but if it’s dropping an old leaf it might presage a new growth to come! best of luck!

[K-Sci]

Originally Posted by Roberta

Phals actually like rather uniform temperatures. Not below 19-20 C at night, warmer during the day. (The professionals can mess with night temperatures for a week or two to "time" the blooming cycle, but they will bloom just fine with more even temperatures)...

I think the 19-20C minimum above is a bit warmer than is necessary. From the AOS:

Temperatures for phalaenopsis should usually be above 60F (16C) at night, and range between 75 (24C) and 85F (30C) or more during the day. Although higher temperatures force faster vegetative growth, higher humidity and air movement must accompany higher temperatures, the recommended maximum being 90 (32C) to 95F (35C). Night temperatures to 55F (13C) are desirable for several weeks in the autumn to initiate flower spikes. Fluctuating temperatures can cause bud drop on plants with buds ready to open.

FWIW, my Mississippi summer daytime greenhouse temperatures are a bit higher than 95F (35C) some summer days, and my winter night lows are now around 60F (16C), increased from 55C (13C) per recommendations from other people here.

I don't believe this is a factor for the OP, however.


-Keith

[Shadeflower]

well if you want to get really technical

my phalaenopsis mannii and sedirea japonica can handle temps down to 12 degrees C.

I have some supermarket hybrids that can handle pretty much the same.

My Phal Bellina I try not to let go under 19 degrees C

My Phal Corningiana gets grown at 27 degrees C (down to 21 at night)

Bottom line for me is that some are warm growing, lots can handle a really wide range being much cooler in winter too.

But I did kill a few of my first phals keeping them too cool, was more the fact I hadn't repotted them and leaving them in too water retentive media they could not handle the cold. So too cold can be risky, it certainly is more challenging to keep the orchids happy while cold than warm i find.

[geob]

Hi everyone!

To give an update - before Christmas, I decided to open (a lot) of vent / draining holes on the pot and get rid of the cache pot altogether, so essentially watering from above.

Since then, its stems keep turning black (which I then cut down) and it has dropped its two small leaves and in the last 2 days it has started yellowing on one of the big ones from its base and today it was half detached.

I am not sure what I am doing wrong here - I am watering once a week and I have used an orchid fertiliser (6ml in 1ltr of water as per instructions)...

When I repotted I transferred it to an eastern room which has more light and is warmer...Theres another orchid in there which is doing great (still in its small pot with a wick).

Including some newer photos...

[K-Sci]

Originally Posted by geob

I am not sure what I am doing wrong here - I am watering once a week and I have used an orchid fertiliser (6ml in 1ltr of water as per instructions)...

Your environment may differ, but in the past my phals went downhill in dry (winter) indoor conditions when watering once per week. A lot of holes in the pot would tend to cause them to dry out faster. Phals hate being bone dry and will begin shedding leaves pretty quickly if it happens regularly. How dry does the media get?

-Keith

[Shadeflower]

I see soil in the bottom of the pot.

Roots are not in good shape.

6ml per liter of any orchid fertilizer is way way too strong.

That will have caused root damage.

And yeah the right balance needs to be found. An airier pot needs more watering. You went from one extreme to the other but judging from the state of the roots one can see through the pot they are all broken and decaying already.

So several things. Whether it can recover from the heavy fertilzing I don't know. If it is only underwatering it can recover by watering more regularly. Or sellotape some holes up again...

It doesn't address the layer of soil that has accumulated at the bottom of the pot.

[Dusty Ol' Man]

After doing a little conversion, I have to say that I feed at about that rate. 30ml/gal works out close to 6ml/L. It would more depend on the strength of the fertilizer used. I use K-lite at 12-1-1. My concentration is 100ppm N.
That said, I do agree the bottom of the pot looks to contain either badly broken down bark and/or soil, and that needs to be changed as quickly as possible. My eyes can't make out the roots clearly enough to say they are rotted.
I would go with a large bark and more frequent watering. I water twice a week, fertilizing every other watering.

[Grautier]

As where I live winter days are cold - even indoors - but humidity is high, I nearly don't water struggling plants. I just spray little amounts of water say once a week.

I never water in the two weeks after repotting in winter nor do I give extra nutrients.

To my knowledge quick shedding of leaves is no sign of to little water. With too littke water the plant would shrivvel. I'd say it is to little light. Plants balance roots and leaves: a greenhouse grown plant will unvariably lose leaves when suddenly living in a living room behind a window. Less light and - if you have central heating - less humidity will be compensated with less leaf surface. As long as the central leaves are ok, there is nothing to fear. Leave the plant alone. Observe. And from the moment you see active root growth, water sparingly and ... observe.

[Roberta]

Whether 6 ml of fertilizer in 1 L is too much depends on the strength of the liquid fertilizer (which is going to be mostly water)... most of us use dissolved and diluted fertilizer that comes as a solid because it is much more economical than buying what is mostly water. But if the OP has some liquid fertilizer, this can be OK, though generally for orchids half of whatever is on the bottle is plenty. But one can't make a judgement without knowing what was in that 6 ml. Very likely, not enough to kill roots. On the other hand, fertilizer is the least important cultural factor... for an unhealthy plant, zero is probably the right amount.