Worm castings are the black gold of indoor gardening. Quite literally worm poop, worm castings have a stellar reputation for their active biology, slow release of nitrogen and micronutrients, and non-burning fertilizer capabilities. Some soils come pre-amended with powerful blends …of nutrients and compost, which can sometimes be too much for seedlings to handle. Worm castings do not have that problem, you can place seedlings directly into worm castings. Additionally, worm castings make an excellent addition to compost teas and organic pre-amended soils. Shop now across our many brands of worm castings.