Treatment of used bonsai soil.
- Thread starter james76110
- Start date
Gabler
Masterpiece
No one ever told me I was supposed to be cooking my soil. I've been reusing it raw for years now.
shohin_branches
Chumono
Lay it in the sun to dry then sift it. So much of bonsai can become overcomplicated that I like to keep this part simple.
Deep Sea Diver
Imperial Masterpiece
Reflecting back on Media Wars. They are often just an assortment of personal thoughts and feelings with little or no factual basis. We have discussed reusing media on at least three other threads, nothing new.
The simple answer is your trees, your choice…
For those interested, the general consensus for the folks with a science background is very similar to the reference article posted earlier. (hope everyone read it. It’s a quick read).
Minimum heat treatment to 212F throughout the media at 30 minutes to kill everything including plant viruses and weed seeds. To achieve a media temperature throughout the batch, heating will require more than 30 minutes. For big batches… say a full sheet pan… my experience is this will take over 60 minutes of heating of the batch isn’t completely dry, including stirring up the core. For dry media likely 45 minutes.
There are three reasons why we heat at higher temperatures… up to 400-450F
Speed - Most of our media goes from wash to - sieve to oven, so there is moisture in the media.
Hardening of kanuma or akadama in the media. Higher temperatures do harden the fragile clay like media. Not rock hard, just harder and still functional.
Caution and Certainty - that the entire batch is pathogen free. -back in the day, where we volunteer, the staff sun dried a couple big batches of media. The trees repotted with this media had issues later on. Since it was back in the day before us, we didn’t observe the trees, but did speak with one of the staff involved. Not pretty. So avoiding any hint of trouble.
Plenty of folks just sun dry. Not saying they are wrong. Are least the media gets recycled and this saves them cash and time. So a positive.
Love the rice cooker idea.
….and that’s all folks!
Cheers
DSD sends
The simple answer is your trees, your choice…
For those interested, the general consensus for the folks with a science background is very similar to the reference article posted earlier. (hope everyone read it. It’s a quick read).
Minimum heat treatment to 212F throughout the media at 30 minutes to kill everything including plant viruses and weed seeds. To achieve a media temperature throughout the batch, heating will require more than 30 minutes. For big batches… say a full sheet pan… my experience is this will take over 60 minutes of heating of the batch isn’t completely dry, including stirring up the core. For dry media likely 45 minutes.
There are three reasons why we heat at higher temperatures… up to 400-450F
Speed - Most of our media goes from wash to - sieve to oven, so there is moisture in the media.
Hardening of kanuma or akadama in the media. Higher temperatures do harden the fragile clay like media. Not rock hard, just harder and still functional.
Caution and Certainty - that the entire batch is pathogen free. -back in the day, where we volunteer, the staff sun dried a couple big batches of media. The trees repotted with this media had issues later on. Since it was back in the day before us, we didn’t observe the trees, but did speak with one of the staff involved. Not pretty. So avoiding any hint of trouble.
Plenty of folks just sun dry. Not saying they are wrong. Are least the media gets recycled and this saves them cash and time. So a positive.
Love the rice cooker idea.
….and that’s all folks!
Cheers
DSD sends
Srt8madness
Omono
Exactly. Unless you're bare rooting the tree, wouldnt whatever is in the shin or remaining soil just repopulate the new sterile media???
And if baking it DOES make it sterile, then what would be the point of throwing out the soil from a sick tree? It is being sterilized or not?
Gabler
Masterpiece
I think the issue is reusing the soil for a different tree. That said, when trees are all kept in close proximity, whatever is in one pot is likely to live in the others, so I think your point still stands.
Deep Sea Diver
Imperial Masterpiece
Gosh… weighing in one final time.
There are pathogens in all bonsai media. It’s just that “good” microbes have outcompeted the “bad” microbes in healthy media.
A tree being repotted has fresh cut root ends and is at its most vulnerable.
Old media is removed during repot. New media, with a different balance of microbes are added.. (with perhaps a couple newcomers). The result is a short term microbial free for all… until a new balance is reached.
This is the point when not so good things can happen. Especially during repots when more media is removed, conditions are inclement and handling is less than optimal.
Best
DSD sends
There are pathogens in all bonsai media. It’s just that “good” microbes have outcompeted the “bad” microbes in healthy media.
A tree being repotted has fresh cut root ends and is at its most vulnerable.
Old media is removed during repot. New media, with a different balance of microbes are added.. (with perhaps a couple newcomers). The result is a short term microbial free for all… until a new balance is reached.
This is the point when not so good things can happen. Especially during repots when more media is removed, conditions are inclement and handling is less than optimal.
Best
DSD sends
Really? I guess the boiling water thing will only kill part then. What temps kill that sclerotia, the scary sounding one that lives in barren soil for 7 years?
I was just reading an article last week that claimed nurseries are causing more disease by importing sterile media and that makes conditions right for bad fungi to overpopulate,
sounded shocking but apparently some believe it. They must be counting bagged soil as sterile.
I’m 99% interested in killing insect eggs - wouldn’t chance reusing soil from a fungal damaged/killed tree anyway.
It “worked”! Hot streamed perlite lol!
I added a cup of water, waited ‘til there was a mini jet if steam from the lid (10min?) and left it for 25min from there. The water boils off pretty much.
I just took the “pot” out and tipped the contents out to cool while I reloaded it.
It “worked”! Hot streamed perlite lol!
I added a cup of water, waited ‘til there was a mini jet if steam from the lid (10min?) and left it for 25min from there. The water boils off pretty much.
I just took the “pot” out and tipped the contents out to cool while I reloaded it.
