I filled some beds about 8 inches with just cow manure late last winter, and it wasn't even that well composted. I direct seeded cucurbits, beets, basil and coriander in it, and transplanted broccoli into it, and all of them are doing great. My best
garden yet, by far.
Some of the beds I mixed some of the underlying soil up into the manure, but the broccoli and cucurbit beds are really mostly just manure the top several inches. The medium feels spongy! The only problem I've had so far is hundreds of alfalfa seedlings because of how the alfalfa
hay is done here. I'm already scheming on how I'll do more beds like this next year but then also top with a deep mulch of dried plant matter.