Penobscot Blend Organic & Natural Planting Mix is perfect for bedding annuals and planting perennials, roses, shrubs, and trees. This specially crafted soil amendment is enriched with compost, oyster shells, and root-enhancing mycorrhizae. Penobscot Blend provides your beds with the diverse, in-ground living soil, drainage, and aeration that your bushes, saplings, plants, and flowers need to flourish all season long.