TerraThrive Worm Castings Vermicompost is our foundational soil amendment that our growers and farmers have used for nearly 30 years to improve the health and fertility of their soils. Our proprietary production process delivers a premium, organic-certified, worm-based amendment that adds organic matter, nutrients, minerals and beneficial microbes to soil. Combine with the soils in your gardens, container pots, fields, orchards and vineyards to rejuvenate your soil, and watch your plants thrive.