Phalaenopsis corningiana specific care

[Shadeflower]

Hello fellow OBers.
Today while browsing over the progress of my different phals I noticed that my P. Corningiana has been on growing strike for far too long indicating something is not right.

So I wanted to reach out and see if anyone else grows a P. Corningiana.

I'm not looking for phal advice, it is only the Corningiana that I feel is not growing like it should so when something like this happens I do more research and my research shows that it grows on limestone in humid forrests and struggles when grown elsewhere.

This initially made me think maybe it needs more humidity but then I remembered an article I read that not all orchids like acidic conditions. There are some (which I don't grow) that prefer higher ph's above 7.

So I looked up what ph limestone has which is 7-8.

It would be a bit annoying to have to make up a seperate feed for just one plant but it needs something changed, at the moment it is grown in a ph of 5.8

I appreciate these posts sometimes turn into lots of theories and I do like different theories but for this one I'd really appreciate someone who has grown a corningiana. MrFakeName, do you have any corningiana's by any chance? I think I will have to try feeding it a different ph and see what happens I suppose. Best way to find out right? but on the offchance someone already has the answer, please let me know what you think or any other tips I could try.

[coldfinger]

Hello,

Sorry, I did not cultivate phalaenopsis corningiana. But, in situ, this phal does not grow on limestone but most of the time on trees that are on limestone soils. It is different. Do not touch the Ph 5.8 it is perfect if fertiliser is suitable . As you say It is indicated by specialists that this phal is slow growing and needs high atmospheric humidity.

But let's see if anyone else grows a P. Corningiana.

[Ray]

My understanding is that corningiana does not do well if nighttime temperatures are elevated, where "elevated" means > 20°C

[Shadeflower]

thanks for those thoughts, them growing on trees makes sense. I have really tried to keep temps above 20 degrees as I thought it was a hot grower but I can try something different there.
I'll look into the temps more. - couldn't find much - only that it's a tricky plant to grow in a greenhouse

So average nightly temps in borneo where they grow is extremely steady between 20 and 21 degrees all year but day temps regularly exceed 30 degrees which I'm not going to start giving it but I will repot it for now and keep it a bit hotter during the day

Thanks for the thoughts

[Mr.Fakename]

I've had troubles with corningiana and sumatrana as well.

What improved their growth for me was keeping them constantly humid, which adds up to what coldfinger and your research suggest.

My "tropical Phal" substrate back then was lava rock, big bark, some BBQ charcoal and good quality Sphagnum, which allowed for frequent watering and good air circulation.
Today I have sumatrana seedlings growing good in rockwool, that I spray daily and water heavily once a week.

From what I remember from Christenson's Monograph, they are found at higher elevations in mountainous areas of Borneo, and don't need 30°C to thrive.

I grow them in medium shade, contrary to very bright shade I give other species like bellina or hieroglyphica.

[Shadeflower]

thx Mr,
I knew if anyone had grown one it was most likely you. It reassures me at least that I'm not the only one that thinks it's a bit trickier so I will be a bit more patient and keep my fingers crossed it grows a new leaf soon

[Shadeflower]

we have an update people. As I mentioned recently I decided to tackle my thrip problem.

This phal was an affected one. It has been a busy period. So washing each orchid with soapy water was not enough, I had to repeat this step with each orchid 1 week later again. This seems to do the trick to catch any eggs that survive the first treatment.

So now that this orchid is hopefully thrip free finally after an entire year of not growing whatsoever it soon started to grow.

As you can see on the picture there is hardly any sign to indicate this plant had thrips, I think they were mainly feeding on the roots but it just wasn't growing so I knew something was wrong and here we go, finally it has woken up. Just wanted to share my observation.

[camille1585]

I'd actually repeat the thrips treatment one more time... It's a lot of work when you have many orchids, but often it's necessary to catch any lingering pests, especially when it's really problematic ones such as thrips or mealy bugs.

Let's hope that the plant will continue growing from now on!! (and then make some nice blooms for you)

[tmoney]

you know, not to add an inexperienced opinion, only an observation i have made in years past with other plants and again last week with orchids.

that observation is that after i soap wash foliage on my plants, after a week they seem to have a little jumpstart in growth. 2 weeks ago i washed about a quarter of our orchids because i noticed some mite bites and sap on one of the Fred black pearls again. so i decided to do several, with a healthy soapy mix this time. and sure enough, most of them showed more vitality 5-7 days later, including 2 phals starting a new leaf.

i have 2 competing hypotheses. one is that removing the dust from the leaves increases photo sensitivity and they get a small boost.

the other is that excess soap which is flushed through the media pulls salts and changes ph a tiny bit for a short time.

either way, it’s a noticeable boost in growth following soapy sprays and flushes.

[YetAnotherOrchidNut]

Originally Posted by tmoney

that observation is that after i soap wash foliage on my plants,

What type of soap do you use? I have seen various recommendations but never from someone who grows orchids.