It appears that when my house was built, the back garden was used as a tip As a result I have clay soil with a large volume of stones of all sizes within it. Additionally, I find the odd piece of metal or plastic buried. I want to get rid of as much of this as possible and replace with a medium that I can grow fruit and veg in. As COVID 19 has reduced my income but given me unlimited time, I'd like to get rid for nothing in the most environmentally friendly way possible. The first border I'm looking at is probably 24 cubic feet. Any suggestions folks?