These spaces can be tricky to improve especially being tucked into the edge and shaded by the trees/forest. I would definitely look into the right type of retaining wall to help support the edge and maybe having different gardens as Shady Green Thumb mentions above. I have spent a ton of money over the years with my landscaper so feel free to call him and mention that Trevor asked you to call his name is David and he would be glad to help you figure this out even if you are a million miles away. His site is shorethingex.com. Good link and please let us know once you do figure thing jam out, we would love to see the results.
