Set the plastic bag into the shallow cardboard box to determine how you’ll want to cut the bag to make it fit into the bottom and up the sides of the box.
Cut the bag to the right size and tape it into the cardboard box. This will provide a waterproof base for setting your seed cartons in position.
Cut the egg carton cups so that they are separated. Each cup will germinate one plant and can be transplanted directly into the container or ground when ready. Fill each cup with potting soil.
Plant your seeds and keep the soil moist with a turkey baster filled with water during the germination period. Avoid overfilling the cups and wipe up any extra water with a paper towel.
Set the germinating seed box in a warm, sunny location and watch as your seeds poke up through the soil.