Earthworm castings is organic fertilizer made by nature.  It exceeds anything chemical fertilizers can do.  Earthworm castings will not harm or burn the youngest, smallest, most tender, plant, seedling, or seed.  Earthworm castings are completely safe for all plants, vegetables, shrubs trees and grasses.  To say it briefly you can not do it wrong and you can not do it better when you use Earthworm castings.  And remember "A Little Does A Lot".  Earthworm castings from SUNSHINE ORGANIC SOIL IMPROVEMENT PRODUCTS are free of weed seeds or any undesirable element.  They are manufactured inside climate controlled buildings.