The problem with burying anything, especially perishables is that you can't easily get to it. And depending on the time of year, snow, rain, etc, it could become a major problem. I like the idea others had about hinding stuff in plain site. Using the hollow space between a wall, intentionally mis-labeling the storage container and piling a bunch of seemingly useless stuff over it, etc, etc. Or if you wanna get really fancy you could always make a fake wall in a closet or cellar with a few feet of storage space behind it. Won't be foolproof but I guess nothing ever is.