AeroGarden Sponges (50-Pack) AeroGarden Grow Sponges are made from pure Canadian Sphagnum Peat and provide soil-free, no-mess, indoor growing all year round Use them with AeroGarden Grow Baskets or Seed Starter Systems for reliable germination and healthy root development Includes 50 AeroGarden Grow Sponges For use with Grow Baskets or Seed Starter Systems in all AeroGarden models