Coast of Maine: HP4000 Indoor Houseplant Mix 16QT: Cape Neddick Blend Organic & Natural Indoor Houseplant Mix is specially formulated for indoor houseplants and flowers using coarse coconut coir, perlite, sphagnum peat moss, and aged bark to optimize drainage and aeration for robust root development. Whether you are growing peace lilies, spider plants, philodendrons, monsteras, or other popular or exotic houseplants, this unique compost-free blend provides the optimum structure and benefits for nurturing strong, beautiful indoor plants and flowers.