I have been learning about mind maps at university and I thought I would combine my interests.
My sister just came for a visit to check on the new bed and she raised an important advantage I hadn't thought of; the bed I have built retains moisture for the plants but it also keeps the plant roots above the water logging zone, which has been a problem over the last few years of higher than average rain. Thanks Sis.
I am now looking for the next experiment in the garden/ hobby farm; maybe something to do with living fences? I have a need to create escape proof paddocks for my sheep.