I thought I'd mention this before I go on with whatever else I have to say on this subject...
You may have read this or heard of this before from someone else but I think its good to repeat to nail down the fundamentals of growing Paphs, most Paphs grow roots very slowly. Most generally don't grow a whole lot of roots per shoot. Some might, but the majority do not. When it comes to waiting for Paphs growing roots or recovering from damage, you must be very patient.
With that said...
I will also say that generally speaking, I don't recommend repotting Paphs too often. It can get a little dicey with some of them as to how well they can recover from this kind of treatment.
There is a caveat to the above mentioned advice, however...
That caveat is how badly decomposed the potting media is. If the potting media is badly decomposed, it can cause some problems with choking the roots out in a few ways. One way is through how much moisture the potting media is retaining. Another way is due to the organic particulate matter that accumulates choking out the roots, particularly if the root mass is not that big compared to the pot size. Regarding whether to repot due to potting media breaking down, my answer would have to be, yes, it is advisable to repot the Paph when the media is broken down pretty badly.
Why would something like the accumulation of organic particulate matter be of concern you ask?
Well, part of the issue is, (and I'm saying this not aware of whether you have been informed about the following), at least one of the Paphs you mentioned is not a true terrestrial. A good example is your
Paphiopedilum charlesworthii. This particular species is actually a lithophyte with the roots growing in between the crevices of limestone boulders in moss or some humus. I advise being very careful about growing this particular Paph in full on moss because there could be too much water getting to the plant, particularly if the media is breaking down badly, and if the root mass is not that big.
The following is photographic evidence of the species
Paph charlesworthii growing as a lithophyte with some information written about the photo. The photos are of the alba variant of the species.
Wild Orchids in Myanmar, Wild paphiopedilums in Myanmar.?????????????????????????????????????????? ???Paphiopedilum
I can also tell you that Paphiopedilum Leeanum is a primary hybrid where the cross is as follows: (
Paphiopedilum insigne x
Paphiopedilum spicerianum).
From what it looks like, the species
Paph spicerianum is a semi-terrestrial that grows on limestone hills. Meaning, that the roots are buried under leaf litter, some loose bark, and a little bit of humus, but beneath that is limestone.
The following link does not really show a close-up shot of how
Paph spicerianum is growing in the wild, but you can get a sense of it from the photos.
Reintroduction of an endangered terrestrial orchid, Paphiopedilum spicerianum----Xishuangbanna Tropical Botanical Garden,CAS
While the species
Paph insigne grows more like how
Paph charlesworthii does, with the roots growing in moss or humus in between limestone rock crevices.
The following photo shows
Paph insigne growing as a lithophyte the clearest.
http://www.slipperorchids.info/paphd...e(insitu)8.jpg
The significance of mentioning the way that these Paphs grow is to understand that some air still needs to get to the roots in order for them to breathe and not rot out.
The Paph Yi-Ying Firework x Paph Enzan Kitty is too complex of a hybrid. But do enough research and you can find out its heritage, and then from there, you can determine what best suits it.
I want to also mention a common factor that you may already be seeing a pattern with...so far, the Paph species that have been discussed grow on some sort of limestone formation. Limestone is primarily calcium carbonate with a few other minerals mixed in it, (probably one of the other most abundant mineral in the limestone would be magnesium based on the dark grey color of the rocks the orchids are growing on). You can guess by now, that I am leading into the supplementation of calcium and some magnesium. These minerals get leached out during the rains and then the orchids absorb those minerals into their tissues to assist with the process of photosynthesis. So it may be a good idea, if you haven't already done so, to add a little bit of calcium and magnesium to your fertilization regimen.
I will also mention that pH matters even with plants. The point of pH mattering in respect to biology was brought up by a college professor during an anatomy class I tried to add by sitting in. The pH of moss is quite acidic, and when it breaks down, it becomes even more so. When organic materials such as bark start breaking down, the pH tends to acidify. The pH of limestone is more alkaline. Since there is more limestone than moss where these orchids are growing, it can be said that the pH is neither all that acidic nor all that alkaline. There is a nice happy range that is probably between 6.5 - 8.5 on the pH scale that these Paphs would do well in. pH is not a linear function, but rather it is a logarithmic function, and changes in pH are actually quite drastic. I am not saying that you have to be measuring the pH of the potting media all the time in order to get it right, on the contrary, it is not necessary to be obsessive about the pH of the potting medium, but do keep that in mind when you choose a potting media, and when you take care of your Paphs.
I have not experimented if there is a significant difference between how well a Paph grows in a clear plastic pot versus an opaque one, but I think I've heard or read the following...
If I'm not mistaken, there are some people who sow Paph seeds that mention the seedling's roots tend to have sensitivity to light. Therefore, many people who sow Paph seeds tend to use agar with charcoal in it so that the roots can grow in the medium without receiving too much light. You may have to ask a lab who has successfully sown Paph seeds whether this is true or not.
I personally have never used clear pots when growing Paphs, so I cannot advise on whether you are able to grow Paphs in clear pots or not.
I hope this gives you some direction on how to take care of your Paphs.