Posted: 21/03/2013 at 22:47
I have a soil base in one of my greenhouses but I rarely grow anything direct into it.
I buy reusable woven plastic supermarket bags, 42cm x 20cm x 30cm and fill them with a mix os soil and compost. Then when they season is over I tip the contents onto the flower beds and start again with frest next year.
I've found concrete/slabs to be too hot in the summer and harbour slugs underneath them. With a soil floor the excess water drains away.