A scythe will work fine on raised beds, uneven ground, anything like that. The trick is to know how to use it, and how to keep it very sharp. Check out Scythe Connection and any videos of the Vido family scything to see proper technique and learn how to properly use and maintain a blade. A good scythe (closest to you in NJ would probably be Scythe Supply up in Maine. A scythe blade, handle, and the tools for sharpening it should cost all told $160, or $200 including shipping. There are no operating costs, and it should last the rest of your life, if you take care of it. I brush out trails in my Christmas tree farm,
hay a meadow and MOW MY
LAWN with the very same tool. The scythe is one tool where it pays to do your homework and learn to use it well. Do not assume you can take it out of the box and away you go. That being said, it is one of the most efficient, elegantly simple tools out there.
Good luck!
One idea is as worthless as another until you actually do something about it, and then it is the action, not the word that matters. --Orson Scott Card