PREMIUM SOIL BLOCKING BLEND with Organic Compost, Worm Castings, Feather Meal, and Greensand - 8 Dry Quart Bag Natural and Organic Soilless Seed Germination Mix. Developed and tested to promote excellent root and stem development for your new seedlings. Follow the manufacturer's instructions for making soil blocks. Made from organic compost, sphagnum peat moss, coco coir, and volcanic pumice. Includes worm castings, feather meal, and greensand in 2 mil poly bag.