So, what's your perfect long petalled paph substrate?

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Reading all the different ideas and concepts here makes me think of which chef makes the best cake.... you can have many different recipes, but they all accomplish the end goal - that perfect slice of cake...

Not to dumb it down too much, as Ray said "what works for you..." but is still think you have to look how the species grew in the wild to get some sense of what we try to duplicate to maintain the best of conditions.
I know that some of the slippers tend to have finer hairs on the roots that can be more easily damaged with our continuous handling over repotting. Anything we can simulate from natural conditions has to work in our favor here. When thinking of our containers, - No, you don't see too many roths growing in plastic along a limestone wall... I wonder too, that while clay pots seem to work well, i think the european stye of clay pot composition has changed over time, where it seems that they add something? to the mix to make it a bit less breakable for shipping.
(am i wrong here???? when you break one of these pots there appears to be a layer that may be some other product whithin the pots. I do remember years ago, when you bought pots made in mexico, they seemed to be a little less "uniform" but also when watering you could see the pot wick the water a bit better...

i have bought and grown multis in net pots, but never see roots growing like the catteleya pictured above.. not sure if we can compare one genus from another that way. While slippers have long trailing roots, that creep through the natural media and rock in situ, they do not appear to have the numbers that you might see on a cattleya or vanda for example..

Tony - by the way... i am finding locally for me anyhow, 6 cu.ft bags of coarse perlite, cheaper than when i tried ordering from OFE or another "orchid media source" and because i buy it locally, no shipping or damage to the entire bag through shipping. I can also get the rockwool cubes (all differnt sizes) from them as well...
Orchid folks are not their mainstay, as most of these companies are now servicing growers in the hemp industry, but the prices are not bad, (and i don't have to pay stupid volume shipping prices, when i can pick it up locally)
just a thought, but you may have already found this yourself.
I have been following this thread with interest, as I'm in the process of examining my Paph and Phrag collection in Semi-hydro the past few days. Generalizing I'd say it's great for Phrags and less than ideal for Paphs. But that doesn't really address what I believe is important here. Ever since Rod McLellan in the 1950s led the move to bark from more traditional growing methods, we have massive repotting (which I hate) as well as fancier and fancier recipes, some of which I'm sure work great. However, with bark I think the freshness of the medium is what is critical. If I'm not mistaken one of the great Paph growers, Terry Root of the Orchid Zone, repotted everything at least once a year (I wish I'd written down what it was), though I don't remember his using a lot of mixes.

Ray, I agree completely, that for orchid growing of all types, it's the water:air ratio at the roots which is critical more than it is the ingredients of the mix. And in my experience (just demonstrated with the difference of Paphs and Phrags in S/H I've found in the last few days) it varies by genus, and perhaps even within one based on adaptations nature has created for plant survival in nature, none of which involve pots.

But focusing on the ingredients of the mix is only half the story in how we create an ideal ecosystem at the roots, and I'm surprised that our ceramics expert didn't point this out, we miss the critical importance of the container and its composition. I've become much more aware of this recently. It started with Catts. I was interested in the approach that Tony Wells takes at letstalkplants, which is basically a wire net pot with leca, and the roots go everywhere, as they would in nature (trying to "contain" them may be our first mistake). So I bought one of his plants. And here it is now. All I've changed is that I mist once or more per day and may water more (I don't know). When I tried to count growing root tips yesterday, I gave up and estimate close to 100. I have never seen an orchid with more roots. Would that I could get that with Paphs.

So what if we expanded our list of media to include such as NZ sphagnum and tree fern and just place in a different container that allows more air to the roots? And here is where you come in, Ray. Experience teaches me that "clay" pots let in more air than those damn plastic ones (even with holes for S/H), but I don't know how THAT compares with say a metal, wood, or plastic net pot. But experience is showing me that orchids are far more adaptable to these materials (with some variation by genus) than to media in plastic pots, so perhaps a focus on mix is the wrong focus. Perhaps even the notion of "containing" is.

This month I bought a couple of Den. cuthbertsonii from Tom Perlite at Golden Gate Orchids. Beautifully grown in moss in clay. The roots were coming out the bottom, and he repotted in Feb. Many report having difficulty with this species. More air to the roots may be the secret. Would a net pot also work? Don't know.

Think for a moment about the traditional "clay orchid pot." Not only does the material "breathe" at least some, but it's also designed to be shallow and has slits for more air "down below." Obviously these were developed for a reason.

And so I've taken most of my Paphs out of S/H, and am trying a number of variations with simple media rather than complex formulas (none "bark"). And yes, Ray, leca with rock wool is one of them, but even there, clay or plastic pot? I'm assuming it would be difficult to keep enough water in a setup with a net pot.

Harvey Brenneise

Interesting observations. In talking with Art (Jr.) Chadwick recently, he says they use a LOT of NZ Sphagnum in clay, for everything from Cattleyas to Miltoniopsis. I’m tempted, but I don’t like sphagnum. Anything I try to add to it (perlite/charcoal) tends to not stay suspended and is hard to keep mixed in proportion. And when it’s time to repot, it’s a mess, I think, to clean out of the roots. Anything I get in sphagnum, even milts, goes into Orchiata mix on first repot. Just my personal preference. Requires a little more water, but that’s ok. I do use clear plastic and with catts and Paphs grow in a bit larger bark than most. I put small holes in the sides of the pots about 2-3” up with a soldering iron for added air. And a cone in the bottom of the pot for aeration.
An interesting aside. I had a Phrag. Eumelia Arias that was growing so well in power Orchiata mix in a 5” plastic pot that when I repotted, it went into an 8” plastic pot in Power + and Super mixture. It grew better than any of my other phrags. Anyone would have said that it was too large a mix for a Phrag and too large a pot, but it sure was happy. I didn’t like the flower particularly and it was such a big plant I gave it as a door prize at a meeting because I have limited space.
I’ve experimented with rockwool, leca, perlite mixes for phrags but always go back to bark although I know some (on this forum) who have tremendous success with that mix. Can’t say why but for me bark works best and I find easiest to work with.
I only use plastic pots.
I don't think clay pots really allow much more air flow, but tend to wick water away from the medium faster. The pores are microscopic, and they probably stay pretty full of water as long as the medium is moist. Lower left is the microstructure of a terra cotta pot.

What are the other photos?
Southern Belle:
thank you for your input....
my apologies if i drifted too much in my conversations, but my focus on this thread was supposed to be based on long petalled paphs,,, ie.. sanderianum hybrids,, as i don't seem to have a problem with my phrags, and pretty much have them sorted out... and for other genera, as folks like Ray mention, "what works for you" in your conditions... I know sanderianum and hybrids, sometimes have finer hairs on their root system, and just seem like a unique issue for me to find a great recipe - wilst knowing what works for one person may not work for another...
Just wanted to get a cross section of what worked for others that grow more than one or two (or 10) of the long petalled paphs....
The more i know about these plants - the more i don't know....
Perfect substrate—who knows?!

I have what works for me: pumice, perlite, and LECA used interchangeably and with those I try to target a ratio of 60% inert media (any/all of those three that don't decay) to 40% orchiata. I don't repot plants annually. I sometimes repot bianually (if the roots are packed in and need more space). But mostly, I repot every 3-4 years. I also use a thin top-layer of moss to support early root development and create a micro climate of humidity around the base of the plant (where new roots emerge)—my 20% rH would otherwise be problematic and lead to aborted roots. I also use tap water (7.9pH, 250ppm CaCO3).

THAT SAID... you're asking about sanderianum which grows with its roots deeply embedded in cracks of limestone and across the moss on the surface of limestone. I have strong feelings about the importance of water chemistry for species native to Calcicolous and Serpentine "Soils"...such as sanderianum, helenae, philippinese, Mexipedium, Phrag kovachii and so on. The rules are not the same for these as they are for epiphytic species, and though some people claim limestone is not water soluble, that is not totally true. Limestone is not "soluble" in the classic sense (it doesn't dissolve to high concentrations like sugar or salt does); however, it is consistently "a little soluble" and a small amount of calcium carbonate does dissolve AND will quickly buffer the pH of acidic and/or pure water. The implication is that the pH near the roots of these species is often alkaline, will rarely go below 6.2, and never below 5.6. This impacts nutrient solubility, nutrient ratios, and also likely means species here have adapted to a set of very specific and consistent not-extremely acidic conditions. Whereas decaying bark, moss and other organic material can push the pH below 5, down to 3pH in extreme cases (when not buffered by the presence of limestone). And as a result we see why "repot annually" becomes a "rule" to follow in the effort to avoid the pH plunge if a person isn't buffering the potting media with something like limestone, oyster shells, etc.

For rothchildianum - it's not calcicolous, but it does come from serpentine soils, which are similarly alkaline (though not high in calcium).
So in my opinion, as long as your potting media provides the moisture gradient, hydration, and airflow that the roots need, and your water is not ever extremely acidic, then it doesn't matter what you plant them in—you know, barring anything toxic. But if you're using peatmoss and/or sphagnum moss, and you're not buffering the pH...then you're gonna run into trouble. That's why (in my humble opinion) a lot of people struggle with the same group of plants: kovachii, mexipedium, tigrinum, roth, and sanderianum.

Here's a resource for more info about calcicolous slippers by Tony Budrovich: CALCICOLOUS SLIPPER ORCHIDS - TALK PREPARED BY TONY BUDROVICH. Paphiopedilum Study Group of Western Australia Meeting 10 April PDF Free Download

And a list of the calcicolous species: Calcicolous Slippers
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