Posted: 09/01/2017 at 12:36
It sounds like a lovely spot. From what you say in second post it seems as though what you may have, is a high water table as the burn runs round and you have silt and sand in various parts of the garden (from past flooding?). If you read any good book that includes a chapter on soil etc what they all say is you can change the STRUCTURE of a soil by digging, composting mulching to improve fertility and aeration but not the underlying TEXTURE i.e. sandy silty gritty clay etc. So you have to work with what you have. Dig a small test pit cover it with a board or heavy plastic, see if the bottom fills with water, then you will know how high the water table is & then how high your bed needs to be to avoid trouble. The only other way would be to lay drains that run into the burn but that would be a huge amount of work.
I quite like a lot of what Charles Dowding says but it seems to me that he is growing in pure compost. If you have access to huge amounts of compost or manure it could be the way to go but remember no dig does not mean no work.
From where you are now I would let the soil get frosted, then as soon as it thaws get as much manure or compost onto it as you can. In spring you can decide whether to dig or plant straight in.