Super Sprouter? Perfect Plug brand growing media replacement plugs are great for seed starting and cuttings. Perfect Plug brand growing media plugs use a custom peat moss blend, with Mother Earth? BioChar added, exclusively developed for Super Sprouter? to allow a great mixture of moisture and aeration. Perfect Plug media plugs have a pre drilled dibble to foster the optimum environment for stem to media contact. If limiting your waste plastic is important to you, use these refill plugs to reload your Perfect Plug Tray? brand starter tray. Easy to use, just insert cutting or seeds into your plugs and watch them grow.