Leaves turning yellow on newly potted Phal

[milan360]

Hi Ladies and Gentlemen,

So with a previous post of mine, I bought a really large Phal from IKEA and came home to repot it in charcoal.

After 1 week all flowers fell off. Well I had to expect that as it was crucial to repot as it was tightly packed in wet sphag moss.

Fast forward 2 weeks, it has been sitting on a sunny area in my home with bright light but not direct sunlight. Beside my existing Dendro Phal (which seems to be doing well now).

I noticed when I came home tonight, that the under leaves were turning yellow and the one directly above it had lighter patches on it. (refer to pic)

What's going on? Should I shift it in to a more cooler shadier area?

Watering schedule is about every 4 days except when it rains. Humidity here is about 80% presently.

[Orchid Whisperer]

The lower leaves turning yellow could be happening just due to old age.

What concerns me is the brown-tinted green of the leaf closest to the camera. Is this sunburn, or something else (rot, etc.)? I would move it to lower light and keep an eye on it.

[milan360]

Oh.. that looks like bad lighting. I had warm and white lighting going on at the same time.

It's pretty dark green. However, now that you mentioned it, the top leaf seems to have lighter patches of green.. here and there.

[estación seca]

I don't see any photos, but every 4 days is probably too often to water, especially with 80% relative humidity. I would expect more like 10 days to dryness. You want to let the roots get dry before watering again with that kind of humidity.

Try using a wooden skewer to check the moisture in the center of the pot. You can find a thread on this in the Beginner forum here.

[wintergirl]

Way too much water. I have lower humidity and I water every 10-12 days. Also they do not need a lot of light.

[Orchid Whisperer]

Re: watering frequency, the OP had repotted to charcoal (from the photos, it appears to be quite coarse charcoal). Every 4 days might not be too bad, but it should be judged based on what the OP is seeing.

In that climate, it it were bark, it would be too often.

I recall a grower in Vietnam (on Orchidgeeks) that also had quite moist conditions but grew gigantic plants potted in charcoal. I don't recall his exact cultural practices though.

[wintergirl]

Originally Posted by Orchid Whisperer

Re: watering frequency, the OP had repotted to charcoal (from the photos, it appears to be quite coarse charcoal). Every 4 days might not be too bad, but it should be judged based on what the OP is seeing.

In that climate, it it were bark, it would be too often.

I recall a grower in Vietnam (on Orchidgeeks) that also had quite moist conditions but grew gigantic plants potted in charcoal. I don't recall his exact cultural practices though.

You may be right. It could be too much sun then. My phals do not like a lot of light.

[milan360]

Hi Everyone,

Yeah, i do check the 'drain plate' at the bottom of my pot to see if there is still a damp spot before deciding to water. It really could be a case of too much sunlight.

I'm peeling my eyes each day to keep a look out for mites and bugs as well. Phals are really a tricky bunch to handle. Every 2 days i spray some plant-friendly anti fungal spray on the roots. Think it has neem-oil.

The charcoal is fresh from the bag. Still 'blackening' my fingers. In general, it doesn't hold water well but gives roots plenty of air in our humid climate. I just haven't mastered the water-light-air circulation ratio yet to succeed.

I have since cut my stem back to the last node before the first flower. Lowest leaf (turned yellow) dropped off as well. I have also shifted the pot further inside my house where there is light but nothing direct or close to the window.

Let's hold out and see how it turns out. I did fertilise it very weakly (second pour , after a first watering) about 4 days back.

Best Regards,

Milan360

[Orchid Whisperer]

Originally Posted by milan360

Phals are really a tricky bunch to handle. Every 2 days i spray some plant-friendly anti fungal spray on the roots. Think it has neem-oil.

There should be no need to regularly spray anything on the roots except water. Over-use of chemicals ( yes, this includes neem) could be part of the problem. Water properly and spraying roots with neem should be unnecessary.

[milan360]

noted with thanks!