Hummus Rich, well draining soil?
I just got a Firecracker Fern (Russelia Equistriformis) that calls for a "hummus rich, well drained" soil. I've been using Al's "5-1-1" and "Gritty Mix" with great results for a few years now.
I read in his posts he does not recommend adding compost, (although I do top dress the gritty mix with leaf mould to conserve moisture and add nutrients).
How would one modify one of these soils for a plant that calls for hummus rich soil?