Virtually any gardener can grow red onions. Red onions are very tolerant of different types of soil. They also grow well in both cold and warm climates, making them the perfect garden crop in almost every part of the country. Even though red onions are tolerant of cold, they should not be planted until all possibility of frost has passed for your area. For best results and highest yields, plenty of organic fertilizer (cow or steer manure) should be worked into the soil before the seeds are planted and additional organic fertilizer should be applied during the critical bulb-growing period.
Purchase your red onion seeds or collect them yourself from your own onions.
Layer 1 1/2 to 2 inches of organic fertilizer on top of your garden soil and then use your spade to work this material into the top 8 inches of your garden soil. Loosen the soil thoroughly and mix in the organic matter well.
Use your finger to poke holes 1 inch deep and approximately 1 1/2 inches apart. Drop one onion seed in each hole and cover with 1 inch of soil.
Sprinkle your garden with water until the soil is damp but not soggy. Sprinkle every day or two to keep the soil damp; more sprinkling will be required in extremely hot weather or if there are drying winds.
Expect your onions to sprout within seven to nine days. Thin your onions to 3 inches apart when your plants have five to 10 leaves--the onions you pull can be used as scallions.
Keep your onions damp at all times. Onions have very shallow roots and drought conditions during the critical bulb-forming stage can result in small or leathery bulbs. Do not be concerned if bulbs grow partly above ground.
Wait for the leaves of the onion plants to droop and lay on the ground before harvesting your crop.