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What to do with soil removed from bonsai trees
Posted: June 20th, 2021, 11:10 pm
by Rob101
Hi All
What do you guys do with the potting mix you remove from your trees and replace with new soil every season ?? .,,.. to date I simply replace with new soil from my local bonsai nursery and dispose of the old either into my garden beds or in my local bush land ...... id be interested to hear what others do ??
Cheers
Rob
Re: What to do with soil removed from bonsai trees
Posted: June 21st, 2021, 7:49 am
by Watto
I try to re-use as much as I can and generally I use the "seconds" to pot up trees I dig. That said I use a completely inorganic mix.
Re: What to do with soil removed from bonsai trees
Posted: June 21st, 2021, 8:03 am
by melbrackstone
Watto wrote: ↑June 21st, 2021, 7:49 am
I try to re-use as much as I can and generally I use the "seconds" to pot up trees I dig. That said I use a completely inorganic mix.
That's pretty much what I do too. Because it's inorganic, most of it hasn't broken down and can be sifted of fines and roots and reused.
Re: What to do with soil removed from bonsai trees
Posted: June 21st, 2021, 9:14 am
by tgward
I try to sift and separate the inorganics and spread to dry in the sun for later reuse then use the rest to top up other house pot plants or put in the compost
Re: What to do with soil removed from bonsai trees
Posted: June 21st, 2021, 6:38 pm
by The Surgeon
I re-use mine also. Mostly inorganic, but as added protection against transferring diseases I put the old mix into one of these.
https://www.bunnings.com.au/maze-245l-2 ... lsrc=aw.ds
Not sure if this helps, but seems to decompose the leftover roots etc. Works for me

Re: What to do with soil removed from bonsai trees
Posted: June 22nd, 2021, 4:05 am
by shibui
and dispose of the old either into my garden beds or in my local bush land
Used potting mix is great in the garden but please don't dump any unwanted garden waste in any bushland. Pests, diseases and weeds can be spread that way and the bush already has enough problems without us adding more.
Please take note of the Surgeon's comment about pests and disease transfer. It is very risky to reuse anything plant related. The smaller the collection the lower the risk is but there is still some risk of infecting healthy plants. Everyone needs to weigh up the risks but you should be aware of the consequences so you can make an informed decision.
I use a lot of the used mix to grow unrelated disease resistant plants - lillies, vegetable seedlings, etc. The remainder is a valuable addition to vegetable beds and other parts of the garden.
Re: What to do with soil removed from bonsai trees
Posted: June 22nd, 2021, 7:16 am
by Watto
I should have said that I also put my sieved used mix into a plastic bag and then leave that bag in the in for a few days, supposedly that will sterilize the substance.
Re: What to do with soil removed from bonsai trees
Posted: June 22nd, 2021, 10:11 am
by Sno
Hi Rob . I spend a fair bit of time cleaning it up before I reuse it .
viewtopic.php?f=12&t=26117
I clean up about four 60 l bins this way . As an ex-nursery man I’ve seen what can go wrong when disease takes over .
Re: What to do with soil removed from bonsai trees
Posted: June 23rd, 2021, 12:24 pm
by Rob101
Wow thanks for your views on this….. ill definitely follow these recommendations
Sent from my iPhone using Tapatalk
Re: What to do with soil removed from bonsai trees
Posted: June 24th, 2021, 3:02 pm
by treeman
Used mix should be solarized after composting (to decompose roots etc) and then mixed with some courser material because you lose some AFP after a while. Other than that you can use it without concerns. You can solarize on any scale you want from a bag to a truckload. Here is some more info..
https://www.youtube.com/watch?v=_0s41m8p9yI