Starbucks Coffee stores will give you great big bag fulls for free. Stir them in, though, or they might clump together. Just add as much material as you can while you are making the compost. When your pile is at least 3 feet high, or when much of it has turned into compost. To help Mother Nature replenish the earth.
Earth is another word for dirt.
Our planet is the only known planet lucky enough to have dirt. Dirt is made out of things that used to be alive, mixed with bits of minerals. Nature breaks down formerly-living materials to make earth. You can help. You can be a part of the natural cycle of life on earth.