Natures Fertilizer, that’s what Black Magic Worm Poop worm castings produced by African Night Crawlers are. Our worms are farmed in a climate controlled environment in Western NY. Worm castings are a highly effective organic fertilizer that will help your plants grow Bigger! So if you own a plant, garden or CBD farm, you should apply black magic worm poop to your plants growing medium. Transplanting, top dressing or premixing soil simply add 4 ounces per gallon of growing medium.