Composting Coffee Grounds

Our local coffee shop here in Tempe — Bunna Coffee — has some very friendly and socially conscious folks as well as great coffee.  We have an arrangement where I drop off an empty bucket and return in a couple days and take some of their spent coffee grounds home. This is a pleasant morning walk each time. The strategy for the grounds is simple so far — I just dig a hole in the ground and dump in the grounds and paper filters, and cover them with the dirt from the hole. This has been going on for a bit over a month now, and there is still lots of room for more. The weather is cool this time of year (lows in the 40s) so not much composting has occurred yet, but I will certainly post here if I have to do anything further in the spring to move it along. My default plan is to do nothing and see what nature does on its own.