Help phalaenopsis declining without obvious reason

[Foxy2702]

I have recently moved on from Phalaenopsis and growing more unusuall type of orchids, but I have few left. I have been gifted a very unusual and beautiful phal but it is not doing too good. I have repotted and treated for fungal and bacterial diseases and yet it is still declining. Leaves are slowly wilting and roots are drying out. I suspect it is dreaded Fusarium however due to plant naturally having purple tinge to its roots, leaves and stem, I can not be sure. How does one check for Fusarium if plant is purple to start with. Please see photos and maybe someone can give me some advise as I really do not wish to loose it, however do not want to put at risk my more valuable orchids.

[DMT]

How often do you water & how much? I have a Phal cornu-cervi & the deep purple color flowers bleeds through the leaves in streaks & dots of purple. Did the flower open as the orchid was declining?

[Orchid Whisperer]

First, from the photos, I see nothing indicating Fusarium. Diagnosis of Fusarium seems to be much more common on Youtube etc. than in real life.

Let's focus on the care you provide and the condition of the plant. How do you water? How often (i.e., what is your clue that it is time to water again)? For example, when I water a Phal, I flush water through the pot for 15 seconds or more, wetting all the medium. I drain, put it back in its growing spot, and don't water again until it is nearly dry. I grow all my Phals in terracotta, so my "signals" are probably different from yours. I look for apparent dryness at the surface and a dry-to-touch pot that is somewhat lighter weight. In plastic, I would look for reduced condensation in the pot, and roots that are silvery rather than green.

Have you unpotted it to inspect/feel the roots? What do you see that indicates to you that the plant is declining in health (as opposed to something like under-watering, just as an example)?

[rbarata]

From the photos I don't see anything wrong with your plant.
I also use transparent plastic pot like the one you have. My cue is root color, silver=dry, green=ok.
Usually, I let it go dry 2/3 of the pot, starting from the top, obviously.

[Foxy2702]

I only water when roots turn silvery in colour and I do not soak rather just water through as it is very humid in my house. , Feed only twice a month, but roots started turning dry and shrivel up. My other phals are doing just great, it does not look too bad but I know my phals and I can see that the leaves are becoming more floppy and soft. I have tried repotting in and still no improvement. It is just a strange but definite decline. Maybe it is just simply bad genetics and a week plant.

[Fishkeeper]

If the leaves are wilting and the roots are dry, it needs more water. Try watering this one more heavily for awhile, it should perk up.

[topun]

If you worry because of an increased purple tinging:

Plants that lack magnesium can show a stronger purple tinge if they have been exposed to unusually low temperatures. The leaves of my Phal. Black Pearl became more and more purple two winters ago.
I researched: plants that lack magnesium have less capability to react to cold the usual way. Vandas are a typical candidate because temperatures never reach this low in Thailand. Moe talked about this on youtube. This - somehow - leads to an increased purple tinge. This does not show unless the plant became cold. I supplemented magnesium over a period of time and the leaves became green again with the usual purple bottom sides.

[estación seca]

I agree, your plant looks close to normal. There is nothing that would make me suspect a disease.

The purple tinge to the leaves is normal in many hybrid Phals, especially ones with pink or purple flowers. Purple leaves are enhanced with plenty of light.

If your relative humidity is low, and roots stay dry too long, exposed roots will shrivel. If the ones in the pot are fine the plant will not notice this. I also suspect you are not watering often enough.

[Orchid Whisperer]

If your pot contains good healthy roots, but very few of them, you could still not be getting enough water to a large leafy plant.

I have posted before about Phals in vase culture, both as a "rescue" method, and as a method for routine care. Essentially, what you do is suspend the roots of the plant in a jar or vase which is normally kept empty. No growing medium.
Fill the vase with water, soak roots for a while,
either without or occasionally with fertilizer.
You will get good root growth, though it will take time.
The plant will never be dehydrated.

Here are some images of 2 phals in vase culture. With and without vases. Plant on left is a rescue just obtained a couple months ago, as a discount shelf purchase. Roots were in bad shape, now recovering.

Plant on right is a rescue that has been in vase culture a couple years. Unfortunately, snails have "pruned" it recently, so the leaves are not in great a condition, but you can see the strong root growth. The roots are a near-solid cylinder that will stand up on its own.

What I am suggesting is that if you have healthy roots but not many of them, try vase culture as a means of bulking up the root mass. It may perk up the leaves.

[estación seca]

Quite a few people use this type of vase culture for many of their orchids. I use it for Vandas. I am happy with Phalaenopsis in semi-hydroponics culture so I use that. I was not able to grow Phals in pots with sphagnum moss, nor with bark.