Posted: 24/04/2017 at 15:20
Your questions have been answered with great patience. If you have taken the time to research RHS advice, why question it on here? And why be rude?
If, as you say, you are a cook, you surely know the only way to see if a recipe works or a flavour combination is good, is to try it so, for heaven's sake, go and try planting something and use the compost advised for the purpose. In metaphor - don't try and use pasta flour to bake a light fluffy cake.