More info and pictures: https://aus.social/@treevan/110293053188000541
One recipe:
Articles:
https://www.biochar-journal.org/en/ct/77-Planting-Urban-Trees-with-Biochar
https://stockholmtreepits.co.uk/ - https://www.researchgate.net/publication/341343983_Tree_Pits_with_Structural_Soils_-_Practice_Note_Version_12
Had to go digging to find what OP was talking about
https://www.theguardian.com/australia-news/2024/jan/29/asbestos-nsw-findings-watchdog-epa-contaminated-soil-childcare-centres-schools-parks
It’s not gardening soil, it’s “clean” fill for big landscaping projects, you wouldn’t replace it with rocks + biochar…
https://lemm.ee/post/33335568
Asbestos now found in sold soil. Whoops.
It’s the same type of soil I was talking about, not gardening soil…
And holy crap, you really don’t let go, do you?
Yes mate, we always get our clean fill from “garden stores”.