Re: Brick Walkway Set With Dirt?
Pull the bricks up, dig out any roots within a foot of either side of the walkway, level and compact the pathway with the existing dirt. Scrap/wash the attached mud/dirt from the brick, the reset the bricks with no space between them. Done - free!
Technically, there should be a base placed under the brick that extends below the frost line. It should be compacted in layers then the bricks set on top. There is a sweepable sand you can used to fill small cracks and voids if you wish. This route, of course is much more work and has added expense. The main benefit is that the walkway will be more stable for a longer period of time than merely placing them on top of the ground as in the first suggestion.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!