Wiggle Worm worm castings is 100% natural. They are an excellent organic plant food that comes to you directly from Mother Nature in their purest form. For millions of years, the incredible earthworm has been one of nature’s greatest producers of readily available plant food.  When used in greater concentrations that found in nature, this non-burning, long-lasting organic nitrogen fertilizer can provide remarkable benefits such as vigorous plant growth, fibrous root systems and improved aeration of the soil.