I think we need to differentiate between raised and edged beds, some raised beds can be quite deep and I have found that they lack moisture if predominately shop bought compost and are very poor at retaining nutrients after year one.
All my beds are edged to a maximum of 200mm (8") but mostly 150mm (6"), I feed the beds regularly with BFB throughout the year and those that will hold brassicas next season will get a good feed with manure. The beds that grow squashes are fed with manure at point of planting. I also have the luxury of space and some beds are left empty each year but covered with weed membrane on top of a layer of compost.
About six beds have been dug to a depth of 600mm (2') and sifted for growing carrots and parsnips with two being left empty each year. My bean frames are permanent and I just dig trenches and replace with compost from my bins, The excavated soil is mixed in with the compost remaining in the bins.
I grow a lot of brassicas and find that compost is too loose as a growing medium and poor at supporting the plants.
All my beds are edged to a maximum of 200mm (8") but mostly 150mm (6"), I feed the beds regularly with BFB throughout the year and those that will hold brassicas next season will get a good feed with manure. The beds that grow squashes are fed with manure at point of planting. I also have the luxury of space and some beds are left empty each year but covered with weed membrane on top of a layer of compost.
About six beds have been dug to a depth of 600mm (2') and sifted for growing carrots and parsnips with two being left empty each year. My bean frames are permanent and I just dig trenches and replace with compost from my bins, The excavated soil is mixed in with the compost remaining in the bins.
I grow a lot of brassicas and find that compost is too loose as a growing medium and poor at supporting the plants.
I am only the Boss because Veggie lets me be!