Mix two pounds of 16-16-16 all-purpose fertilizer into 100 square feet of soil before planting the onions in early spring.
Use a hoe to dig furrows into the soil that are 1 inch deep and as long as you would like them to be based on the number of onions you will be planting. Place the onion plants into the soil 3 inches apart and cover them with soil. Firm the soil around the plants.
Water the onions for at least ½ hour weekly. When the weather gets warmer, water two to three times per week for ½ hour.
Apply ½ cup of ammonium sulfate 21-0-0 fertilizer per 10 feet of planted row four to five weeks after the onions are planted.