Bluegrass Reggae Fusion
 

This bluegrass band, Brushfire Stankgrass is great. Not only are they a great and talented bluegrass band, but they are great at blending genres. A decent amount of their songs are definitely reggae or at least go into little reggae jams. They also get pretty straight up rock at times, anyways check them out:
https://www.youtube.com/watch?v=UXcpqgnFoTA
^Harvest Reggae