I would spread enough pine needles & such, ONLY as hiding the fresh dig, but no more than needed. If a cover is put over the site, make sure it can breath, so lack of air supply doesn't kill your soil. When I first started "making" my soil, I ask the Nursery people what compost they used, because their livelihood depends on good plants, but they won't use the overpriced shit.. just good shit. A bottle of Compost Tea will activate the microbes, and they LOVE molasses & liquid seaweed. With this, you will grow monsters.