I’m so stoked about this forum!
So, I live in the southern part of Sweden and have tried a few different substrates for my trees the last 5 years. I begun using a type of danish moler which is used as cat litter, cheap and easy to find. I mixed the moler with crushed pine bark (the mix that Harry Harrington use). It worked ok for me the first three years.
But after three years I changed to a mix of crushed leca and rough peat moss after reading everything that Walter Pall ever written on the internet
And then came Mirai Live! And I, who never tried akadama but still feared it, saw Ryan Neil explaining the unique properties of akadama. I really trust in the knowledge of Ryan, I haven’t seen anyone presenting bonsai horticulture in such a scientific way before!
The main thing that is brought up in discussions regarding the usage of akadama in mid/north europe is that it will experience passive breakdown, leaving a solid clay brick in the pot due to freeze/thaw-cycles. I also saw a video with a guy from America that conducted experiments on freeze/thaw-cycles and the akadama he used broke down really bad.
Should I use akadama/pumice/lava mix here in Sweden? We have long winters that experience periods with temperature dropping to -15°C (5°F) aswell as periods above freezing with rain. How are the winter weather conditions in Portland, Oregon compared to Sweden?
I’m sorry for the wall of text, but I’ve had this on my mind since I started watching Mirai Live, and since the timing of the live Q&A:s is really bad for me I thought that i’d give it a try here to see if anyone can give my mind some peace
I would say that if you have something that works for you–stick to it. With that said I have had great luck with Akadama and my temperatures can get down to -15°F (zone 5b). One thing I noticed as I went through the soil escapade is the rate of decomposition. Ryan refers to this in a number of his videos where they are doing root work. Often the breakdown of Akadama forces finer root formation as the roots have to push passed the Akadama and in the process of breaking it down are splitting. This however can mean that you’ll need to repot slightly more often than with other substrates.
I have an uncle in Canada who swears by Turface, Haydite, and an organic component. His trees are remarkable and he frowns on the increased use of Akadama because of it’s tendency to break down. He limits repotting as much as possible and I found often had 1-2 year longer intervals than I had with my trees.
Long story short. If you prefer what Harry is using maybe go for it. Does it fit your watering schedule? I think that is the hardest part and isn’t focused on too much. Sometimes what works best for some isn’t best for you simply because they have the time to water. I wouldn’t worry so much about the freeze/thaw cycles as long as you are keeping on eye on things and repotting when it is time.
Just my two cents
*edit: Forgot to add. I use what we call “Boons Mix” aka Clay King I believe (don’t quote me on that one). Which is roughly 1/3 Akadama, 1/3 Pumice, 1/3 Lava Rock (Scoria). I adjust the ratios depending on the size, species, and development of the tree.
Thank you for taking the time to give an in-depth answer! You have some really good points. I have also noticed when Ryan is talking about the breakdown of akadama due to the growth of roots, this is one of the aspects I find really interesting about akadama.
What I’m worrying about is the “passive” breakdown of the akadama, that is the breakdown happening without the roots causing it! It’s nice to hear that you don’t experience this even with freezing temperatures
I will have to try the boon-mix and see how the akadama behaves here!
Thanks again for your answer!
Ryan has said in the recent BSOP stream that in his opinion, the one (and so far only) decent akadama substitute is Diatomaceous Earth (which is what I believe Danish Moler is). I would say if you are interested in a test, you could get some akadama and try it side by side, but you may already have access to a good component in your area without having to import akadama.
As for the climate of Portland, OR, I can take a shot at answering that. I live here in Portland too. Temperatures in the winter will get below freezing but not much. For the next week, we are predicted to have lows between 25F and 29F (about -4 to -1 Celsius I think) with a few inches of snow each day. I would say normally this will happen a once or twice a year, but mostly our winters stay above freezing, are overcast and with a lot of moisture in the air. I don’t know how that ranks against southern Sweden in the winter, but I think it’s probably colder in southern Sweden in the wintertime than here in Portland.
Hi @nmhansen! Thanks for the answer
Yeah, I’ve been watching the stuff Ryan has been saying about akadama substitutes. What I fear is that the danish moler we use here in Sweden is the non-horticultural kind of DE. I have decided to order akadama from a guy in the Swedish bonsai society, I will have to see if it hold up to the conditions here. From what you say about the winter climate in Portland, it seems that it is a bit more warmer and with more moisture.
Have u considered using high quality akadama and reduce its ratio in the mix by adding some moler clay? Just an idea
In Turkey, we explore Zeolite Clinoptilolite for Akadam replacement. We yet need to see the results though. I guess it is also mentioned in the soils stream as an alternative for Canadians.
The cat litter we have in Sweden is made of Danish moler, the producer is called Damolin. On the website they claim that it is usable for horticulture, it is called terramol and the moler consist of approx 1/3 clay and 2/3 diatoms. I have used it for a couple of years with success.
About the akadama. My general concerns would be that our climate here would indeed passively break down the akadama fairly quick, which forces us the repot more often than we should. All the positives are still there but it would be expensive and are you sure you can obtain high quality akadama in Sweden?
Probably the best thing to do is to test it, get a bag, repot a couple of trees and see how it behaves.
Terramol by Damolin is a good product in my experience. I imported 4 tons in Cyprus 10 years ago and i was using it to pot yamadori olive trees (100% terramol). I also used it mixed with pumice and chipped bark (1/3 each type) for many trees. It worked well. I cannot comment on the refinement of the roots/branches as i had nothing else to compare it with.
Hi Erik,any update?
Akadama can breakdown badly in south UK where temperatures are not that cold (zone 9 about -5 C) but constant Frost, especially affects small particles. After one year I had to replace the top layer (as suggested by Ryan) but with Danish moler which is working well although is not as easy to realize when needs watering.
About good or bad quality akadama is particularly tricky when one have to buy online.
So for me is better a mix o danish moler, akadama,lava and some organic… Perhaps a bit more organic that 15% helps reducing watering.
I have switched over to 100% akadama for my deciduous trees and 1-1-1 pumice-lava-akadama for my pines. I constructed a greenhouse this winter and bought a heating device which has kept the greenhouse at around 2 degrees celsius all winter. It has also kept the rain and snow at bay. The greenhouse and the heating device has elimnated all the problems of the akadama and so far the trees are healthy and the akadama seems to hold its shape.