Cover the bottom drainage holes with window screen to prevent soil from escaping from the holes when you water.
Fill the container to the top with potting soil.
Plant scallion seeds 2 inches apart over the soil surface and cover them with one-half inch of additional potting soil.
Saturate the soil evenly with water immediately after you finish planting the scallion seeds.
Place the container in a location that receives full sunlight with a temperature between 65 and 86 degrees Fahrenheit.
Provide regular water to keep the soil evenly moist. Do not allow the soil in the container to dry out.
Loosen the soil gently and pull the scallions from the soil when the tops reach a height of about 6 to 8 inches. Use the scallions while they are fresh and green for savory recipes.