Hi Banksiaman
I think you'll find that most non fig native you try with this
fast growth method will go to heaven very quickly

. Our natives have generally evolved into very good feeders in highly nutrient deficient soils and this method places them in the exact opposite medium. I realise that banksias like their tucker and maybe you could try it on one that you're prepared to read a eulogy over, but i wouldn't put your pride of place in one that's for sure.
As an aside (as i look at your user na- i picked up my first two banksias a few days ago - i'm not even sure of the variety they are, but i'm madly reading up on them in the forum. How are you on the identification side of things? The nursery could tell me what they were

as they were in the ready to die section.
Welcome to the forum by the way

I hope you'll have as much enjoyment as i do!
Stew