Wow, thank-you all for such quick and helpful replies. I shall try and address each of your questions / points as accurately as I am able, but bear in mind I am novice with a poor grasp of the correct terminology. ALAN - Thanks for those two most helpful links and for the kind words of encouragement...

Hello, I am new in these here parts and unsurprisingly I have stumbled across this veritable pantheon of gardening knowledge in search of help. I live in a flat in London and although I do not have the luxury of a garden, I do have access to a rather large roof space. As I love cooking, I thought it...