leroycoutts wrote: I can generalised from the post, but don’t want to do that.
I am looking for specificity.

Do as the nursery owners do.
Nursery soil, mostly organic.

Being specific:
In my country, in my region, with my tropical seedlings and saplings I use:
40% black garden soil, 30% vermiculite,
30% sand.
DON'T use it as a recipe unless you live in São Paulo and grow tropicals.

Clicio wrote: DON'T use it as a recipe unless you live in São Paulo and grow tropicals.

How is that for specific!

leatherback wrote:

Clicio wrote: DON'T use it as a recipe unless you live in São Paulo and grow tropicals.

How is that for specific!

I’d say much more helpful. Similar weather conditions here too though a few degrees warmer. I’ve probably seen a bit more volcanic burnt earth being used here, maybe around 20-30%. I mostly am growing tropical so this is helpful.