Poke 20 holes, each 1/4 inch wide, sporadically into the bottom of a plastic 5-gallon bucket using a hammer and a 3-inch-long nail. Poke another 20 holes around the bottom side wall of the bucket 1/2 inch from its bottom edge. Space these out as best you can, they don't have to be perfect. You just want to make sure the soil can drain well.
Fill the bucket with garden potting soil until the soil is 5 inches below the bucket rim. Poke three, 2-inch-deep holes spaced 3 inches apart in the center of the bucket with a pencil. Drop a corn seed in each of the holes and cover the holes with soil.
Set the 5-gallon bucket in the bathtub and sprinkle 1-gallon of water over the soil. Water may or may not come out of the holes at the base of the bucket.
Lift the bucket out of the tub and move it to a sunny, warm location in the house. A south- or westward-facing window is best for this. Place a plant pot saucer on the floor or table and then place the bucket inside the saucer. The saucer will catch any water that drains out of the bucket.