Calgary Bonsai Society

I'll play the newcomer card again and steal with pride to start this thread. Since I am just now gathering the books, seeds and tools to start this hobby, I'm not in a great position to type anything pertaining to soils. Jeremy has taken the time to type out a few comments, and I'll transfer his text word-for-word to start this thread and try to keep the main post up to date as the discussion develops.

My soil mix is:

- 1 part River Sand (Aquarium Mix - Stay away from ocean sand...too much salt - look for shells in the bag and stay clear - Source: Petland)

- 1 part Number 3* chicken grit and screen out grains larger than 1/4" (Source: UFA).

- 1 part Schultz Aquatic (sometimes at pet stores or Green Gate) or other diatomaceous earth (Oil Cleanup available at Walmart). I have used Flourite in the past (available at pet stores), but it's messy, it holds liquid 4-ever and tends to decompose and splinter like shale (the one plus side is it's a calcined clay that is loaded with Iron -- you don't have to worry about adding Iron chelate to your ferts). Schultz aquatic is the best I've found simply because it's Arcilite (sp?), a high fired calcined clay that does not break down -- FYI: Arcilite is the white rocky bits in the Schultz Orchid Mix. From what I have read Arcilite is about as close to hard akadama you can get in terms of water-to-air retention -- or cation exchange capacity, as people who know what their talking about (not me), call it - and it doesn't break down in two years like akadama. Allegedly, akadama is the "perfect" CEC substance -- don't know, don't care, can't afford it.

- 3 parts Schultz Orchid Mix (Walmart) or just Fir Bark (Garden Retreat). I screen out grains larger than 1/4" and smaller than 1/16". If you are using Schultz Orchid Mix there is already horticultural charcoal inside. If not, then add 1 part hort-charcoal.

The end result of this standard mix works out to (3:3). 3 parts organic to 3 parts inorganic.

* For shohin (trees less than 24 inches) I use Number 2 grit (screen out grains smaller than 1/16'') and aim for a grain size of 1/8" in all soil components.

When I am potting Pines I will reduce the organic component to 2:3 and 1:3 for Junipers. When potting moisture loving plants like Maples I use a 2 parts organic to 1 part inorganic and tend to use smaller grains (1/8").

I am looking for a source of lava rock and pumice in a 1/8"-1/4" size. When I find it I will try switching to Boon's pure inorganic mix and see how it fairs.

So in my ongoing search for the components to Boon's mix I have made some progress...I finally found Pumice and Lava Rock in this town...WOW...who knew it would be this challenging?

I went to Burnco first. They wanted an arm and a leg for lava and their pieces were enormous. I called every landscaping company in town and none of them had any. Green Gate had lava, but again the price was high and the size was large. Eventually I went up to Golden Acres and found Dutch Secret (I think that's what it is called) -- one litre bags in a usable size (price: not great at $6.00, but better than anything else I've found).

Pumice was exceptionally hard to find. I called landscapers, building suppliers, masonry supplies, pet stores, pool suppliers, landscape suppliers, golf courses, farm suppliers and a number of garden centres -- any place I could think of that might carry pumice. Eventually I contacted Edward's Garden Centre and they said they thought just might have what I was looking for. To my great satisfaction, they did; 4 gallons worth (price: again not cheap, $30.00).

Granite I've got already and charcoal can be purchased in bulk for cheap at Pisces Pet Emporium.

The final ingredient is Akadama. Nobody in town carries it and it is absurdly expensive to order in (35.00 CAD plus shipping for a 1 litre bag).

Whoever may be reading this should justifiably be asking: "Is it really worth it?"

At 35.00 a bag plus 30.00 in shipping it most certainly is not worth it, but it sure would be nice.

I have imported trees from Japan growing in pure Akadama, and their root systems are fantastic and quite frankly far superior to any of my trees growing in the granite, schultz aquatic, river stone and fir bark mix.

Why?

I've been trying to figure this out for some time now.

It seems that it is a combination of it's porous structure that facililitates a cationic exchange capacity which is moderately high at (21 meq/100g), the fact it maintains it's structure under a frequent watering, sunlight and fertilization regemin and most importantly (and least discussed) the fact that it is somewhat soft.

A lot of bonsai growers praise Turface and other "Kittydamas" as superior to akadama for their ability to resist breaking down. Very few take into consideration that a little bit of breakdown might in fact be beneficial. The beautiful thing about akadama is that it maintains its structure under frequent watering (and therefore maintains excellent filtration of air and water) but is soft and porous enough to allow roots to penetrate it.

Many people in North America use fir bark in their mixes (i.e. me) but fir bark is generally very hard and the roots have a heck of time penetrating it. The roots grow around the wood, and the wood is full of tanins and other unfavourable chemicals that make it a less than ideal organic addition to a soil mix. At first I thought these criticisms were unfounded, bonsai purist, nonsense ("Well the Japanese have used akadama for decades, so why use anything else"), but the fact is all of my trees growing in akadama are healthier with much finer and robust roots systems.

Colin Lewis suggests that with the now fashionable, excessively firm and granular mixes, the roots occupy somewhere in the range of 30% of the total potted volume with the rest being occupied by inpenetrable granite, lava, pumice and high fired clay. In softer, akadama based soils the the roots occupy up to 60%. When efficient root systems are are crucial (as they are in bonsai) the merits of akadama become obvious.

But...the price is not right.

So what to do? Compromise I suppose.

I'm going to substitute Schultz Aquatic (or Turface) for akadama in my conifers and use mix of Schultz Aquatic and Sphagnum Peat in my deciduous (keeping my maples moist enough in their fir bark-based mix has been very challenging -- hopefully the peat will help). I don't like the idea of using peat because of the non-renewability and the very high CEC (150 meq/100g) which with the high CEC of the Schultz Aquatic could lead to root burn if I am not careful -- I must remember to flush the soil regularly. The upshot is greater soil stability, less repotting and better cold weather tolerance -- the drawbacks have already been discussed. I'll keep you all posted on the results.

If you have any questions or suggestions on my mix please let me know.

Thanks,

- Jeremy

No thank you.. that is sometimes the dilemma we face especially up in the canada, We have to compromise by substituting other material sometimes. Please do post pics.

Hi Eric,

I've been pretty busy at the office of late and I'm playing in 3 bands and that chews up a lot of time. I am still getting everything prepared; the lava and pumice are not quite the right size so I am crushing it by hand and it's slow going, but on the bright side, I should have enough mix to last me two potting seasons. When I have everything ready I'll take a few shots of the mix constituents before and after incorporating them in the final product.

I am super psyched about having Les come down. I need all the hands on experience I can get.

Hope to see you all there,

Jeremy

Granite grit, #1, #2 & #3, are available from UFA Co-op at 4635 - 1st St SE at about $10 for a 25 kg bag. Turface is available atWestgro Horticultural Supplies at 1557 Hastings Crescent SE, which is at the east end of 42nd ave SE, past the UFA, for about $18 for the 22.7 kg bag. Good stuff but needs screening and has lots of small particles.

I will be going to Victoria on the first week of October for the Pacific Northwest Bonsai Convention, and will be picking up some supplies for myself. (Akadama was $35 for a 30lb bag at Japan Bonsai last time I was there) and they usually have pumice and lava. I paid $15 for a twenty pound bag that last time. If anyone is going, there will be lots of supplies there at the convention. I might have extra room in my truck for a bag or two for someone who wants it. Let me know - there is lots of time.

Elf

Hi Elf,

I'm not sure if you received my email, so in case you didn't, I most certainly would like to take you up on your offer. Please let me know what you need from me. Please drop me a line by email at bonsaibass@gmail.com

Thanks,

Jeremy