As most of you have read many times I use as substrate baked loam/zeolith/chabasai/pumice/lava split/ turface/ or similar (one of those or mixes -makes NO DIFFERENCE) 85 % and add 15 % rough peat. Nothing else!
I keep getting requests what in the world this miraculous rough peat is and where one can buy it. We get it in any garden center and it very cheap . It is bog soil of not decomposed sphagnum moss. It is also called 'white peat' which leads to further misunderstandings because it is not white!
It is the ideal addition to the rough particles because it holds water, maces the reaction more acidic, contains lots of humin acid, which acts as hormones.
This mixture of 85 % particles plus 15 % rough peat I use for all trees. Look at my galley for results.