ewest, I do the same thing, but use 10 foot metal conduit as the stake. They are very cheap and the Christmas trees will slide down the pipe very easily when waterlogged. I just tie a short piece of nylon rope to the tree with a loop knot on the end and slip the loop knot over the pipe. With the metal conduit pipe, you can drive it into the lake bottom with a fence post driver. Each year I add a couple of trees to each structure. Don't have to worry about the stake rotting.
