Miracle-Gro® Expand 'n Gro® Concentrated Planting Mix is a great substitute for potting mix or garden soil as it can be used in-ground or in containers. The compressed coir and plant food expands up to 3X when water is added and feeds plants for up to 6 months. It holds up to 50% more water than basic potting soil and creates up to 90% more air giving your plant's roots all the room they need to thrive.