I'm in the Atlanta area and am looking for perrenial plants that will grow very fast and can be chopped down (partially) for mulch. I'm hoping to find something woody/shrubby that gets a little large (10' to 20') so I can harvest a lot of biomass from it continuously. I have some areas that get 8 hours of direct sun, and a lot of other areas that are either full shade, or partial shade.
I've done some searching on this but can't find anything specific to my area and a lot of what I find is geared to more northern areas. I also find a lot of suggestions for smaller non-woody plants likee Comfrey and other low cover grops, which I do intend to use, but I'm hoping to find more woody perrenials to add even more biomass to my soil.
Forms clumps/hedges that make good natural terraces. You can cut the clumps regularly with something like a hedge trimmer and let the grass lie as a mulch. Really deep rooted and once established can tolerate drought and flood. Vetiver can serve a similar purpose to swales - slowing and holding back surface water to increase infiltration.
Moderator, Treatment Free Beekeepers group on Facebook.
Willow? It has been used for a long time in England as a biomass plant. The real vigorous growth doesn't come until the second and third years, so it is often on a 3-5 year coppice cycle. There is even a Willow Biomass Project at this link if you want more info. It does particularly well in wet spots in our thick Georgia clay.