Pumice: where do I find it?

[Roberta]

Originally Posted by Asian Cymbidium Empress

Hi Roberta:

I would like to point out your statement about the fall cooling down. I don't know where people get this idea, it's wrong for Cymbidium goeringii.

Cymbidium goeringii's flower buds are induced and set in the middle of the summer (in the midst of Asian Summers, at least in the 30C+/86F+ where I am dying from the heat (I lived in Taiwan in my childhood and I always avoid visit my mom in the summer June/July/August).

My point is this: setting/inducing the buds have nothing to do with the cool temperature in the fall. By September, October, it is already too late to set/induce the buds, you already past the window of opportunity.

You need the cool/cold temperature from late fall throughout the whole winter to hold the bud to make sure that it doesn't blast and the low temperature is required for proper flower developmet (agricultural term is called vernalization).

I hope this makes sense.

It does make sense. I am not sure that DirtyCoconuts was particularly asking about Cym. goeringii. I was talking about hybrid Cyms... in fact, some of the Asian species are used in the breeding to get hybrids that don't need that cool-down (which many of the "standard" types do need) But Cym. goeringii and hybrid Cyms require very different conditions ( I have never had success with the former, the latter grow easily for me) Different animals...

[Asian Cymbidium Empress]

Roberta:

I just checked out rePotme's website. They do have kanuma and akadama. However, they don't have all the sizes. Also, the ones they sell are the cheapest and lowest qualities ones. They will break down within 1-2 years and create water log in the pot. Once they crumble, they will not provide the aeration Cymbidium goeringii requires to do well.

[DirtyCoconuts]

i have no wedding to goeringii or any cym…

i am looking to find out if there are cyms that can tolerate my area and then, if so, if my style and "gear" will be able to work for them.

I like to both multitask and not invest too much effort into something if there is a possibility it will be a non-starter

i am gathering that i can accommodate them if i can find some hybrids that are able to 1) survive the heat and 2) be happy enough to give flowers.

thank you both for the extensive information and assistance

[Asian Cymbidium Empress]

Cymbidium goeringii must be grown in the pH range between 5.5-6.5 (slightly acidic). I only use Japanese Cymbidium mix directly from Japan. The 3 pumices are used are called HARD Kanuma, BAKED Akadama, and Satsuma. It is the standard potting materials for temperate East Asian Cymbidium such as C. goeringii. I live in Toronto, Canada and believe me, I searched and searched in Canada and the US. You can get REGULAR Kanuma and REGULAR Akadama and Satsuma in some bonsai stores in the US but I think it’s a hit and miss. You might be able to get some components in bonsai stores but not all and you have to buy in large quantities. The regular Kanuma and regular Akadama are too soft so they crumble too easily (I experimented with it and the media crumbled in 1 growing season and created waterlog), so if you use regular Kanuma and regular Akadama, you probably need to repot every year. The Hard Kanuma and Baked Akadama (treated at a very high temp), the materials become very hard so they don’t crumble as easy. The 3 pumices are very specific with very specific pH:
Baked Akadama: pH range between 5 - 5.5, this material is most water retentive material
Hard Kanuma: pH range between 5.2 – 6, this material, the roots will stick to it. You need this since it provides the terrestrial property
Satsuma: pH range between 5.7 – 6.5, this material is the most porous (the least water retentive material).
When these 3 materials are mixed in a predetermined ratio, they provide the perfect pH, perfect balance for water retention and drainage. In this Mix, you only need to repot every 3 years. You will need 3 grades of the mix, large, medium, and small to pot them properly in the traditional Asian method. This is the standard potting materials in Asia, there is nothing special about them, all the books and vendors use the same type of materials, so I don’t substitute and I don’t question the reasonings.
Once all my C. goeringii (a collection of Japanese orange flower clones), they double in size every 2-3 years and they bloom every year. I posted my plants/flowers. They are budding again now at the end of the summer (end of July, early August) and will bloom again next Spring.
To get them, you have to fly to Japan to get them, I think it’s the easiest way to get it as it is too frustrating to search them in North America and try to make your own mix (you have to buy each component, 3 materials x 3 sizes, so 9 different large bags of materials, if you can find them). I buy premixed large bags in Japan and I just use them directly out of the bag, it’s the easiest way and I don’t need to think about it.

[Shadeflower]

alright lets see, 9 large suitcases, a travel pass, and a return flight to Japan.
That shouldn't be too hard this time of year

[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.