Pumice: where do I find it?

[Dusty Ol' Man]

Every beginner who reads this will be forever turned away from ever wanting to grow Asian cyms. Way too much work and expense. Overly complicated. I can't fly to Minneapolis, let alone Japan!

[Ray]

Originally Posted by Dusty Ol' Man

Every beginner who reads this will be forever turned away from ever wanting to grow Asian cyms. Way too much work and expense. Overly complicated. I can't fly to Minneapolis, let alone Japan!

Only if they don't think outside of the box.

I imported about 500 Asian cymbidiums a month a couple of decades ago. They arrived bare-root and were immediately put into S/H culture, where they thrived.

My source in Taiwan grew them in sort-of S/H, as well, but used coarse pumice and sticks as the medium, watering them daily with river water containing spoiled milk.

[Asian Cymbidium Empress]

These are the 2021 Cymbidium goeringii blooms, I forgot to post them here in the spring. I don't think I need to explain too much, the pictures should just talk by themselves. All blooming size C. goeringii produced flower buds in my collection except one plant and the the success rate for blooming them (without blasting the buds) is more than 90%. They are all grown in Toronto, Canada and they can bloom like the way you see them in Japan. They are all grown in the Japanese Cymbidium Mix. They bloom every year like this and they are all budding again now. There are too many buds so in the fall, I have to get rid off some buds so they don't bloom themselves to death.

To grow East Asian Cymbidiums properly require a lot preparation and thoughts, and unfortunately, they are not flexible (unlike Neofinetia or Dend.moniliforme). East Asian Cymbidiums are intermediate to advanced orchids, they are definitely not a beginner's orchid since the culture is very complicated (standard/mini hybrid cymbidium protocols do not work). I found sources for the pots and potting materials and experimented with one cymbidium goeringii for 3 years to optimize the growing and flowering conditions before I started collecting them.

The standard bark mix (bark/charcoal/perlite) doesn't work because Cymbidium goeringii is a terrestrial orchid. If you water them every day, they will rot. There is an alternative to the Japanese Cymbidium Mix and that is 50:50 bark/pumice mix. Cymbidium goeringii will grow/live in this alternative mix but they won't thrive. The people I know who grow them this way have thin/sparse foliage, and they rarely bloom (if they bloom at all). So in this alternative, it is hit and miss (mostly miss). There is something about the Japanese Mix that just work. The Asians have been growing East Asian Cymbidiums for thousands and thousands of year, so there must be reasons why they use this Mix.

I fly to Japanese one every 2 years preCovid and I have a stock pile of the potting mix so I am good for another 3-4 years or so. Since I cannot fly to Japan now, I will ask my source(s) to ship them to me. It's not a problem, there is always a solution to get the mix.

[Shadeflower]

Hey Asian Cym grower,
I think it's great you have specialised in this cym variety and your adamance that you understand them better than anyone else made me smile.
I am a big fan of pumice too as most know but like you have discovered there are varying different qualities and if you end up using bad quality it can be worse than just average lecca.
It's frustrating that every bag of pumice needs to be washed thoroughly and these days I filter out pieces that don't float to eliminate any bad pumice.
As such the amount of usable pumice that is left is very expensive compared to bark and perlite.

I'm very happy with results in bark and perlite, I just prefer using a substrate that doesn't degrade which makes repotting easier, so far I have compared bark +pumice to a few different media and bark +pumice still gives amongst the best results.

I hear what you are saying about bark+pumice but your comparison means nothing to me.
It doesn't just come down to what media is used, it depends on the grower and what he waters with too.

To have a valid comparison you should grow in bark + pumice and compare. Using your friends plants grown in bark+pumice is just not a justifiable reason to conclude your substrate is the only factor involved.

[Asian Cymbidium Empress]

Yes, I agree that dry pumice is very dusty and it is annoying to clean/soak them. The Japanese pumices I use, they are heavy, so they don't float on top of the water, they sink, so every single pumice in the mix is usable (good to use, nothing is wasted).

I struggle with East Asian Cymbidiums for many years and once it's pottd in this Mix, all the problems associated with growing it are resolved.

Of course, the conditions, water quality (clean water only), light, humidity....etc are important, but I think people overlook the importance of the potting mix. IMO, it's important to grow them in this mix as you can see from my flowers and plants.