When you're ready to begin a new crop in the Planting Block, first be sure that the styrofoam block has been thoroughly disinfected (warm water with a splash of bleach is fine). Then soak 40 of the Jumbo Bio Sponges in warm water for a few minutes. They expand, revealing the pre-drilled planting hole at one end. Simply slip one seed into the hole of each Bio Sponge, place the Sponge seed-side-up in the cell of the Planting Block, and you're on your way to another bumper crop of healthy, strong, super-quick seedlings!
You can also purchase a replacement 40 Cell Jumbo Bio Planting Block and 40 Bio Sponges.