I also tried my hand at creating hedgerows/earth banks after seeing an example on David Dormvik's blog the Sole Member of the Napoleonic Connoisseur's Society. I think they worked quite well; thanks David! I might try making another half dozen and adding a bit more eg. twigs to represent fallen logs, trees etc. to make it really look like bocage-style hedgerows.
Strips of balsa wood covered in wood putty and dry brushed with raw sienna artist's acrylic. Stones inserted into drying putty; glued where necessary.