Coast of Maine Castine Blend Organic Raised Bed Mix is a soil mix that is designed for outdoor raised garden beds. It is an enriched blend of manure compost, worm castings, lobster and kelp meals, mycorrhizae, greensand, and biochar. This blend helps retain moisture and improve aeration, making it great for growing vegetables, herbs, and flowers. It is OMRI listed and is ready to use straight out of the bag.