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
Fuck me that’s brutal