I have been WSing for about 6 years and I have seen many directions which say do not cover seed, or press seed into the soil, but I never do. I always cover the seed with at least a little sprinkling of dry mix and then water them in. I feel this is the way it is meant to be. All my small seeds: petunias, lettuce, chives, poppies are covered and all grow quite well. Those little tufted grass seeds are engineered to blow around, so I anchor them with a little dirt.