Made from volcanic rock, Lava Rocks are small pebbles of porous clay, giving them the innate ability to absorb and gradually release water over time.  Lava Rocks are capable of increasing humidity around your indoor plants. They act as a propagation medium for plant cuttings or as a semi-hydroponic indoor plant growing medium. Lava Rocks can also be added to plant soil or compost to create better drainage for your plants. These little rocks are finding themselves becoming a staple part of keen botanists' repertoires. To learn more about Lava Rocks, read our piece in the Clay Journal about them. Delivery: Nationwide ADDITIONAL INFORMATION Each Bag contains roughly 1.5L of Lava Rocks. Height: 27cm Width: 15cm Depth: 10cm