Place potting soil into an egg carton. Fill each socket up with dirt. Sprinkle a couple of snapdragon seeds on top of the soil and place in sunlight. Do this 6 to 8 weeks before you expect the last frost. Water the seeds sparingly.
Dig a 2-inch-deep row in your garden in an area that receives direct sunlight or light shade. Add about 1/2 inch of compost or peat moss and mix with the same amount of soil.
Place the seedlings into the row about 1 inch apart. Fill with remaining soil and water.
Pinch back the plants after you see about five leaves on them. This will encourage the plant to crow bushy instead of tall.
Tie the plants to a stake with a soft cloth when they reach about 12 inches tall.