I had never done any kind of layering before, so about 6-7 weeks ago, my first 4'x8'x12" raised bed of this year started with me removing all the soil from last year, which involved cutting and removing about 20# of bermuda grass rhizomes that had grown underneath it and up through it. I then soaked the soil with vinegar, then laid in several layers of brown packaging paper and backfilled with last year's soil and about that much more new mulch. Seems to be keeping the bermuda grass at bay so far, even after multiple deep waterings. Now we have beets, spinach, jalapeños and cayenne peppers started and happy.
In the fall, I'll do it again, but probably add more layers of newspaper, cardboard, leaves, manure, etc. Also probably get some "free firewood" from craigslist or tree trimmings from local bulk trash pickup days. Lots of that available around here. Just have to wonder about how organic that stuff could be. Guess I could ask homeowners if they spray their trees.
My current winter bed as of Jan 11:
